Embed Size (px)
Citation preview
t-i”..’= “--- .“--’ -
i --’
. .
.
.._ .....
.“.:
. . .. .
. ..’.- ...
,.
f“”””””’..,.,.
.
FLEET WEATHER CENTRAL/JOINT TYPHOON
Guam,MarianaIslands
---.
,
i
r’
WARNINGCENTER
‘
SEE EDGE INDEXON BACK COVER
. ....u&J+e* - ..a..+=.-& *----- -- - .“ .. .<- .4. -.
From:
To:Via:
Subj :
Ref:
U. S. FLEET WEATHER CENTRALJOINT TYPHOON WARNING CENTER
COMNAVMARIANAS BOX 12
FPO SAN FRANCISCO 96630
FWC/JTWC: HLH: lmr
521~/4 21Ser.16 JAN 1970
Commanding Officer, U. S. Fleet Weather Central/JointTyphoon Warning Center, GuamChief of Naval OperationsCommander, Naval Weather Service Command
Annual Typhoon Report, 1969; submission of
(a) OPNAV Instruction 3140.17E of 29 Ott 65(b) SECNAV Instruction 5600.16 of 2 Nov 60
1. The Annual Typhoon Report, 1969, is submitted herewithin accordance with reference (a).
2. During calendar year 1969, 13 typhoons, 6 tropical stormsand 4 depressions were detected in the Western North Pacificfrom the International Date Line to the Malay Peninsula. Atotal of 430 warnings were issued during the 108 calendar daysof “warning status” for the Joint Typhoon Warning Center, Guam.
3. Reference (a) directs Fleet Weather Central Pearl Harborand Fleet Weather Central Alameda to foreward annual summariesof tropical cyclones in their respective areas to this commandfor inclusion in Annual Typhoon Reports. Fleet Weather CentralPearl issued no tropical cyclone warnings during 1969. FleetWeather Central Alameda was in warning status 67 days during1969 and issued a total of 219 warnings on 4 hurricanes, 6tropical storms and 5 tropical depressions.
4. This report has been reviewed inence (b).
J
,.,Y. H;
I
)
accordance with refer-
U. S. FLEET WEATHER CENTRALJOINT TYPHOON WARNING CENTER
COMNAVMARIANAS BOX 12
FPO SAN FRANCISCO 96630
J. H. NEGELECaptainr U. S. Navy
COMMANDING
JOHN J. R. KINNEYLt Col, USAF
DIRECTOR, JOINT TYPHOON WARNING CENTER
STAFF
CDR Herbert L. Hansen, USNLT James H. Bell, USNLT Ralph E. Jacobs, USNLT Michael A, McAllister, USNCAPT Henry M. Baddley Jr. USAFCAPT David F. Solem, USAFTSGT William W. Harra, USAFSGT Thaddeus C. Settle, USAFSGT Larry M. Plotkin, USAFAG3 Kenneth R. Klingenrneier, USNAG3 Jessie J. Scoggins, USNAG3 David L. Gnilka, USNAG3 Dennis C. Holcomb, USNSGT Louis M. Ballard, USAFMrs. Lillian M. Rau
TRANSFERS DURING 1969
SSGT Joseph Halsteter, USAF ,SSGT John H. Depew, USAFAG3 Richard P. Flakr USNAG3 Joseph L. Mangan, USN
1969ANNUAL TYPHOON REPORT
0H
ad
--y-+
%2-z
---n
lx-
l-l
CJ
d--n
‘8L
a!>
..
-0=r
cddHE
l
FOREWARD
This report is published annually and summarizes WesternNorth Pacific Tropical Cyclones. Annex A summarizes TropicalCyclones from 180 degrees eastward to the North American Coast.
When directed by CINCPAC in May 1959, CINCPACFLT redesig-nated Fleet Weather Central Guam as Fleet Weather Central/JointTyphoon Warning Center (FWC/JTWC)r Guam with the following re–sponsibilities:
1. To provide warnings to U. S. Government agencies forall tropical cyclones north of the equator and west of 180degrees longitude to the coast of Asia and Malay Peninsula.
2. To determine tropical cyclone reconnaissance require-ments and assign priorities.
3. To conduct investigative and post-analysis programsincluding preparation of the Annual Typhoon Report.
4. To conduct tropical cyclone forecasting and detectionresearch as practicable.
Air Force Asian Weather Central at Fuchu, coordinatingwith U. S. Navy Fleet Weather Facility Yokosuka was designatedas alternate JTWC in case of failure of FWC/JTWC Guam.
The JTWC is an integral section of FWC/JTiVC Guam and isauthorized to be manned by three ~Air Force and three Navyofficers and five enlisted men from each service. The seniorAir Force Officer is designated as Director, JTWC.
The Western Pacific Tropical Cyclone Warning System con-sists of the Joint Typhoon Warning Center (JTWC) , the U. S.Air Force 54th Weather Reconnaissance Squadron stationed atAndersen Air Force Base, Guam and U. S. Navy Airborne EarlyWarning Squadron One (VW-1) stationed at Naval Air Station,Agana, Guam.
The Joint Hurricane Warning Center in Hawaii, a coordinatedagency composed of the U. S. Weather Bureau, Honolulu, the AirForce Central Pacific Forecast Center, and Fleet Weather CentralPearl Harbor, is responsible for tropical cyclone surveillanceand issuance of warnings in the Central North Pacific area be-tween 180 degrees and 140 degrees west.
U. S. Navy Fleet Weather Central, Alameda, California, isresponsible for issuance of warnings from 140 degrees westlongitude to the North American Coast.
i
TABLE OF CONTENTS
Chapter 1A.B.c.D.E.F.G.
Chapter 2A.B.c.D.E.
Chapter 3A.
B.
c.
D.
E.
F.G.H.I.
Chapter” 4
Operational ProceduresGeneral ------ ------ ----- ----_- _____ ----
Analyses and Data Sources ------ ----- ---
Forecast Aids ------ ------ ----------- ---
Forecasting Procedures ------ ----- ----- -
Warnings ------ ----------- ----- ----- ----
Prognostic Reasoning Message -----------
Tropical Weather Summary ------ ----- ----
ReconnaissanceGeneral ------ ------ ------------ ------ --
Reconnaissance Responsibility ------ ----
Evaluation of Data ------ ------ ------ ---
Communications ------ ------ ------ ------ -
Summary of Reconnaissance Support ------
Joint Typhoon Warning Center StudiesAn Analysis of Tropical Cyclone WindVelocity Forecasting Accuracy ------- ---
A Discussion of Tropical Cyclone ForecastVerification Methods and Seasonal Dif-ferences in Forecasting Difficulty -----
Frequency Distribution of Error in JTWCOfficial Forecasts ------ ------ ----- ----
Causes and Cures for Forecast ErrorsExceeding 200 N.M. ------ ------------ ---
A Comparison of Objective Techniques forTyphoon Movement ------ ------------ -----
Confidence Forecasting ------------ -----
Fujiwhara Effect-Case Studies ----- -----
Climatology ------ ------ ------ ------ ----
Satellite Data Fix Accuracy ------------
Summary of Tropical Cyclones 19691969 Tropical Storm and Tropical De-pression tracks ----- ------ ---------- ---
1969 Typhoon Tracks ------ --------------
Summary of Western Pacific TropicalCyclones of 1969 ------- -------------- --
1969 Tropical Cyclones ------------ -----
Tropical Depression Position Data ------
Tropical Storm Position Data ------ -----
Forecast Verification ------ ------ ------
Twenty-Year JTWC Official Forecast Ac-curacy ------------ ------ ------ ------ ---
Forecast Error Tabulation --------------
Distance Between Operational WarningPositions and Best Track Positions -----
1969 Average Forecast Errors ------ -----
Individual Typhoons of 1969 24-HourVerification Error ------ ------------ ---
1969 Right Angle Forecast Errors ------ -
1-1
1-1
1-21-31-41-51-5
2-12-12-12-22-2
3-1
3-8
3-13
3-17
3-193-243-283-403-43
4-14-2
4-34-54-74-8
4-11
4-124-13
4-144-15
4-164-17
ii
5-Year Right Angle Error Comparison----
Chapter 5 Individual Typhoons of 1969Phyllis -------------------------------Susan ------ ------ ------ ______ ______ ---
Tess ------ ------ ------ -----_ ------ ----
Viola ------ ------ ------ ---_-- ------ ---
Betty ------ ------ ------ ------ ------ ---
Cora ------ ------ ------ ------ ------ ----
Doris ------ ----- ------ ---------- ----- _
Elsie ------ ------ ------ ------ ______ ___
Grace ------ ----------- ----- ----- _____ _
Helen ------ ------ ------ -----_ ______ ---
Ida ------------ ------ ------ ------ -----
June ------ ------ ------ ------ ------ ----
Kathy ------ ------ ----- ------ ----- -----
Annex A Summary of Tropical Cyclones in theEastern North Pacific1969 Tracks of Tropical Depressions andTropical Storms ------ ------ ------ -----
1969 Hurricane Tracks ------ ----_- -----
Summary of 1969 EastPac TropicalCyclone Season ------ ------ ------ ------
Summary of 1969 Reconnaissance ----- ---
Tropical Depression Position Data -----
Tropical Storm Position Data _.--A------
Individual Hurricane Tracks for 1969 --Hurricane Bernice ------ ------ ------ ---
Hurricane Doreen ------ ------ ----_- ----
Hurricane Glenda ------ ------ ------ ----
Hurricane Jennifer ------ ------------ --
Appendix A Abbreviations and Definitions ------ ---
4-18
5-15-7
5-115-155-195-235-295-335-395-455-495-535-57
AN- 1
AN- 2
AN- 3AN- 5AN- 6AN-7AN-9
AN-11AN-15AN-19AN-23
AP- 1
iii
CHAPTER I
OPERATIONAL PROCEDURES
A. GENERAL
Services provided by the Joint Typhoon Warning Center (JTWC)include forecasts of tropical cyclone formation, intensification,direction of motion, speed of movement, wind intensity andchanges in the size and intensity of the cyclone. The primaryproduct of JTWC providing these services is the tropical cyclonewarning issued in 1969 at 05Z, llZ, 17Z and 23Z whenever tropicalcyclones existed in the JTWC area.
FWC Guam provides computer and analysis support for JTWC.
Communications services for JTWC are provided by the FleetWeather Central Nimitz Hill Division of Naval CommunicationsStation, Guam.
B. ANALYSES AND DATA SOURCES
1. FWC ANALYSES:
Surface polar projection isobaric; 0000Z, 0600z,12002 an~”1800Z.
b. Surface mercator projection isobaric; 0600Z and18002.
Surface micro-analysis of South China Sea region;00002, O~60Z, 1200Z and 1800Z.
d. Sea surface temperature charts; daily.
e. Checkerboards (Stidd Diagrams) of selected tropicalstations.
f. Time cross sections of selected tropical stations.
2. JTWC ANALYSES:
Sectional surface isobaric charts; hourly and 3hourly a~”required.
b. Reconnaissance data.
c. 700 mb mercator projection contours; 0000Z and1200Z.
d. 500 mb mercator projection contours; 0000Z and1200Z.
e. 300 mb mercator projection contours; 0000Z and1200Z.
f. Stidd diagrams of selected stations in the van ofan approaching storm.
1-1
3. SATELLITE DATA:
The quality and quantity of satellite data available in1969 was greater than ever before. ESSA 6 (later replaced byESSA 8) and NIMBUS 3 provided local morning direct readoutpictures. Nimbus 3 provided infrared direct readout picturesat night. Local afternoon ATS satellite pictures were availableas a rectified digitized mosaic chart after an eight hour delayfor processing.
4. RADAR:
Installation of weather radar at FWC Guam was completedin time for the 1969 typhoon season, but did not see much action.
5. COMPUTER PRODUCTS, 0000Z AND 1200Z:
a. Hemispheric analyses and barotropic prognoses for1000 mb, 700 mb, 500 mb, 300 mb, and 200 mb.
b. Decomposition fields of the 500 mb (SD, SR and SL)analyses and prognoses. The SD, SR, and SL fields correspondto small scale disturbances, mean flow and long wave patternrespectively.
Computer analysis of tropical streamlines for the700 mb, :60 mb, 400 mb, 300 I’llkI,250 mb, and 200 mb levels fromFWC Pearl fields were used in 1969.
d. The HATRACK typhoon steering program based on SRprognostic fields was used on an operational time basis as aforecast aid.
e. The TYRACK typhoon steering program was operation-ally used during the 1969 season. This program utilizes theFWC Pearl tropical streamline fields for determining forecastmovement.
f. Divergence charts based on FWC Pearl streamlinefields were produced for evaluation beginning about 20 July.A preliminary report is included in Chapter III.
c. FORECAST AIDS
1. CLIMATOLOGY:
The following climatological publications were utilized:
a. Tropical Cyclones in the Western Pacific and ChinaSea Area (Royal Observatory, Hong Kong), covering 70 years oftyphoon tracks.
Climatological Aid to Forecasting Typhoon Movement(lst Wea%er Wing).
1-2
. Climatological 24-Hour Typhoon Movement (McCabe,J. T., 1~61).
d. Western Pacific Typhoon Tracks, 1950-1959 (FWC/JTWC).
e. Far East Climate Atlas (First Weather Wing February1963).
f. Annual Typhoon Report, 1968 (FWC/JTl?C), coverin~tracks for 1959 - 1968.
2. PERSISTENCE :
Extrapolation of storm movement using averagemean direction was the most reliable method for 12 toforecasts.
3. COMPUTER PRODUCTS:
speed and24 hour
. The HATRACK typhoon steering program was run on theFWC Guamacomputer on an operational basis during 1969. Steeringforecasts were made using the decomposition mean flow fields(SR) of the 700 mb, and 500 mb levels for prognostic fieldsthrough 72 hours. Empirical modification based on apparenterror in earlier forecasts was used to obtain improved fore-cast positions.
TYRACK computer forecast steering from the 700 mb,500 mb, ~60 mb, 300 mb, mean 700/500 mb and mean 700/500/400/300 mb levels were used during 1969.
4. OBJECTIVE TECHNIQUES
During 1969 the following individual objective fore-casting methods were employed:
a. ARAKAWA - surface pressure grid model.
b. HATRACK - based on 700 mb SR prognosis.
HATRACK - modified from 700 mb SR prognosis for 12hour err~~. (for 24 hour forecasts)
d. HATRACK - modified from 700 mb SR prognosis for 24hour error. (for 48 hour forecasts)
e. HATRACK - based on 500 mb SR prognosis.
f. TYRACK - based on program-selected best steeringlevel from Pearl tropical fields.
Evaluation of these techniques is contained in ChapterIII.
D. FORECASTING PROCEDURES:
1-3
An initial track based on climatology and extrapolation isdeveloped for a 3 to 4 day period. The track is modified byconsidering the existing and forecast upper air patterns, numeri-cal steering forecasts and the ARAKAWA objective method.
Subsequent forecasts become “educated” by longer periodaveraging of extrapolation error in speed and direction andthrough modification of computer forecasts to compensate forerrors observed in earlier computer forecasts. A combinationof extrapolation and climatology is the starting point for eachforecast, with mesoscale analysis of the 700, 500 and 300 mbcharts and the ARAKAW’A objective forecast model used to modifyor reinforce the extrapolation forecast. Position of tropicalcyclones with respect to the 700 mb high center and ridge tothe north and the 700 mb trough or break in the ridge to thewest are the primary keys to 24 hour forecasting of recurvatureor speed changes. The 200 mb level has been used to anticipatechanges in intensity through assumptions of divergence in thesoutheast quadrant and convergence in the southwest quadrant ofanticyclones. Tropical cyclones approaching a 200 mb anti-cyclone from the southeast are forecasted to intensify and thoseemerging from the west side of a 200 mb anticyclone are normallyforecasted to weaken.
Extended range forecasting is based on extrapolation ofthe 24 hour track with reversion toward climatology and modifiedby SR and SL 500 mb forecast contours.
The resulting official forecastobjective and subjective techniquesand direction the weighted favorite
E. WARNINGS:
is an integration of bothwith persistence in speedfor short term forecasts.
Tropical cyclone warnings are numbered consecutively with-out regard for upgrading or downgrading of the storm betweenintensity stages. If warnings are discontinued and the stormagain intensifies, warnings are numbered consecutively from thelast warning issued. Amended or corrected warnings are giventhe same number as the warnings they modify. Forecast positionsare issued as follows:
Tropical depressions 24 hr
Tropical storms 12, 24, and 48 hr (72 hr at 05Z and17Z only)
Typhoons 12, 24, and 48 hr (72 hr at 05Z and17Z only)
Forecast periods are stated with respect to warning time.Thus a 24 hour forecast verifies 26 hours after the aircraftfix data, 29 hours after the latest surface synoptic chart and29 to 35 hours after the latest upper air charts.
1-4
Warning forecast positions are verified against the corres-ponding post analysis “best track” positions. A summary ofresults from 1969 is presented in Chapter III.
F. PROGNOSTIC REASONING MESSAGE:
Whenever warnings are being issued, an amplifying messageis issued at 06Z and 18Z. This prognostic reasoning messageis intended to provide meteorological units ashore and afloatwith technical and non-technical reasoning appropriate to thebehavior of current storms and the logic of the latest JTWCwarnings.
G. TROPICAL WEATHER SUMMARY:
This message is issued daily from May through Decemberand otherwise when significant tropical cyclogenesis is fore-casted or observed. It is issued at 0600Z and combined withthe prognostic reasoning message when warnings are being issued.It describes the location, intensity and likelihood of develop-ment of all tropical low pressure areas and significant cloud“blobs” detected by satellite.
1-5
CHAPTER II
RECONNAISSANCE
A. GENERAL
Land station and ship reports continue to be scarce inareas of tropical cyclone formation. The tropical cyclone warn-ing system depends upon aircraft reconnaissance data to fix thelocation and strength of tropical cyclones. Only on rare occa-sions are land radar fixes or sequential reports available tocompare with reconnaissance data. Increased satellite coverageduring 1969 proved to be an invaluable aid in scheduling air-craft reconnaissance to achieve maximum effectiveness. Inter-pretation of storm intensity and center location from satellitepictures only is presently not sufficiently reliable for opera-tional use. Continuous surveillance of tropical cyclones isof the utmost importance as illustrated by the explosive deep-ening of typhoon Kathy on November 6 from a system requiringgreat skill and persistence to locate in the afternoon to anighttime reconnaissance indication of 60 knots only 12 hourslater.
Four fixes per day were scheduled on all tropical cyclonesfollowing the initial fix which was normally coordinated withthe earliest availability of reconnaissance aircraft on thescene. As a general rule VW-1 made fixes at 09002 and 15002at low and intermediate levels and 54WRS made fixes at 21OOZand 03002 at intermediate (700 mb) level. High level (500 mb)fixes were made on storms in the vicinity of higher terrain.Most storms were taken into warning on the basis of daylightinvestigative flight data.
B. RECONNAISSANCE RESPONSIBILITY
Squadrons responding to the reconnaissance requirements ofJTWC through the TCRC in 1969 were U. S. Air Force 54th WeatherReconnaissance Squadron (54WRS) flying WC-130 aircraft fromAndersen Air Force Base, Guam and the u. s. Navy Airborne Early
Warning Squadron ONE (VW-1) flying WC 121N aircraft from theNaval Air Station, Agana, Guam.
c. EVALUATION OF DATA
Eye data from tropical cyclones is provided by low levelpenetration, intermediate level penetration or radar fixesfrom outside the center. Penetration data provides the bestquality data including dropsonde soundings, minimum 700 mbheight and sea level pressure, maximum observed wind (estimated),shape and character of the eye and feeder band information. Theprimary center of the cyclone is based on the location of min-imum pressure at the surface, a parameter best obtained by lowlevel penetration, however the nearly vertical structure ofmost tropical cyclones promises only slight loss of accuracyon intermediate penetration fixes. Radar fixes made outsidethe center introduce an attenuation and radar accuracy errornot present in penetration fixes. Radar fixes are also basedon the radar center rather than the pressure center of the storm.Not infrequently reports of centers determined independently by
2-1
wind, clouds, pressure and temperature will vary by 10 miles ormore. The eye report contains a subjective estimate of fixaccuracy which must also be taken into account in the deter-mination of the storm location at warning time. A final factorin this determination is the forecasters ability to accuratelyforecast the direction and speed of movement of the storm. Ona statistical basis this error rate is 4 to 5 miles per hourof forecast time. During 1969 the mean difference between thepost analysis warning position and the published operationalwarning position was 20.7 N.M. Since the mean time differencefrom fix to warning time is two hours the forecast error contri-bution is 9 to 10 miles leaving a residual value of 11 N.?!. at-tributed to the mean accuracy of reconnaissance fixes.
Short term variability in the actual cyclone track and themean amount of “smoothing” incorporated in the best track analy-sis are subjective factors included within the 11 N.M. accuracyaccorded reconnaissance fixes in operation use.
Ilaximum differences between warning positions and best trackpositions resulted when reconnaissance was not continuouslymaintained, when the developing storm has an indistinct andshifting center or when fix positions used for the warningposition fell well outside the past season best track analysis.
D. COMMUNICATE ONS
The primary means of communication between JTWC and recon-naissance aircraft was voice single sideband through AndersenAirways (AIE 2) serving as the primary air to ground stationfor both 54WRS and VW-1 weather missioris. Secondary air toground stations were Clark AFB, I?uchu Airways and Kadena Airways.When secondary ground stations were used eye data was passed toJT’WC via the Joint Overseas Switch (JOSS). Eye data messagesreceived by Andersen Airways were simultaneously received atJTWC by direct phone patch. A hard copy backup message wastransmitted from Andersen over local teletype circuit SDE 9.
Average delay time from time of fix to receipt in JTWC byphone patch was 20 minutes including message preparation timein the aircraft and time to copy the message in JTWC. Haximumdelay time by phone patch was 1 hour 21 minutes and minimumdelay just a few minutes. Direct communications with reconnais–sance aircraft permitted direction of aircraft on synopticmissions into areas of suspicion appearing on satellite.
E. SUM14ARY OF RECONNAISSANCE SUPPORT
A reconnaissance fix accreditation system was devised in1965 in an effort to establish an objective evaluation of recon-naissance effectiveness. The system has been in use with minormodifications since that time.
Fix times are scheduled as near as possible to warning timeto still permit receipt of the data for consideration by JTWC
2-2
forecasters before release of the official warning. Prior to1967 it was necessary to schedule fixes three hours before warn-ing time. Improved communications in 1967 made it possible toschedule fixes only two hours before warning time.
AIRCRAFT RECONNAISSANCE DATA
(NUMBER OF FIXES AND INVESTIGATIONS)
1961 1962 1963 1964 1965 1966 1967 1968 1969—— —— —— __ _,
350 496 465 772 666 674 845 807 468*
*76 preliminary or intermediate (No Credit) fixes not included.
In addition there were 203 synoptic tracks flown in 1969.
TABLE 2-1
DELAY IN RECEIPT OF RECONNAISSANCE FIX DATA FOR 1969
NUMBER OF MAX DELAY MIN DELAY AVG DELAYMETHOD CASES* TIME TIME TIME
PHONE PATCH 402 1 HR 21 MIN O HR 01 MIN O HR 20 MIN
SDE 9 49 2 HR 11 MIN O HR 10 MIN O HP. 33 MIN
OTHER 33 1 HR 57 MIN O HR 10 MIN O HR 30 MIN
*Does not include 60 fixes made on cyclones that did not develop.
TABLE 2-2
2-3
MAX DELAY TIME
AVG DELAY TIME
MIN DELAY TIME
PERCENT OF EYEMESSAGES DELAYEDMORE THAN 1 HR
NUMBER OF FIXESy RECEIVED AFTER
& WARNING TIME
PERCENT OF FIXESRECEIVED AFTERWARNING TIME
COMPARISON OF DELAY TIMES WITH PREVIOUS YEARS
1965 1966 1967 1968
60 HR 09 MIN 4 HR 33 lIIN 11 HR 20 MIN 6 HR 25 MIN
1 HR 05 MIN 1 HR 02 MIN 0 HR 43 MIN O HR 25 MIN
0 HR 09 MIN FEW MINUTES FEW MINUTES FEW MINUTES
39% 38% 16% 4%
34 30 23* (j*
5.7% 5.4% 3.1% 0.7%
*since lg67, fixes scheduled 2 hours prior to Warning time ViCt2 3 hours priortime during previous years.
TABLE 2-3
1969
2 HR 11 MIN
O HR 22 MIN
O HR 01 MIN
2.8%
3*
0.6%
to warning
,,
DEFINITION OF FIX CREDITS AND EVALUATION OFTIMELINESS OF RECONNAISSANCE FOR 1969
CLASS DEFINITION
1 FULL CPSDIT
2 I?ULL CREDIT
3 EARLY/LATE
4 VERY EARLY/VERY LATE
5 ATTEMPTED BUTMISSED FIX
6 MISSED FIX
7 FULL CREDIT
8 FULL CREDIT
9 NO CREDIT
1969
From 1 hour before to 1/2 360hour after levied time.
Aircraft in assigned areawithin 1 hour before to 1/2hour after levied time butunable to locate a center. 14
Center located 1 to 1 1/2hours before or 1/2 to 2hours after levied time. 10
Greater than 1 1/2 hoursbefore or more than 2hours after levied time.
Recon provided some usefulperipheral data but no fixwas made. Reasons mayinclude clearance problems,mechanical trouble, lowfuel, etc. o
Missed fixes not fallinginto any category above. 6
Fix made on investigativeflight or synoptic track. 32
Investigative flight, nofix made. 49
Preliminary or intermediatefix made between scheduledfixes. 76
TABLE 2-4
2-5
CHAPTER III
JOINT TYPHOON WARNING CENTER STUDIES
A. An Analysis of TropicalAccuracy.
1. BACKGROUND:
A revised techniquevelocities was used in 1969.
Cyclone Wind Velocity Forecasting
for forecasting maximum windIt is based ~n a smooth curve
extrapolation of central pressures along the forecast track.The forecast central pressure and forecast latitude are usedas arguments to enter the JTWC pressure/wind correlation toobtain a forecast velocity. Modification of this initial fore-cast velocity is made subjectively according to the stormsposition with relation to the subtropical ridge, divergencepatterns along the track, cloud organization as depicted bysatellites and the sea surface temperature gradients whenappropriate.
2. DISCUSSION:
Errors in forecasting by this technique result from:
a. Normal instrument and/or reporting error in centralpressures reported by reconnaissance aircraft.
b. Latitude error in the forecast track.
c. Failure of the intensity curve to follow the pat-tern established
Aircraftlevel of + 5 mb.in the pl~cementminimum pressureincluded in this
during early phases of the storm.
dropsonde pressures are used on the confidenceBoth instrument error and minor differences
of the dropsonde relative to the absolutein the eye on consecutive soundings areconfidence level. An analysis of the past
several soundings is used to determine a consistent trace. Lowlevel aircraft penetrations with direct readings of pressureimprove the confidence level somewhat and provide anchor pointsfor the tendency curve.
Errors in forecast latitude displace the entry on thepressure-wind correlation graph but generally contribute only5 knots or less to the total error.
The primary source of error resulted from the break-down of the extrapolation assumption when, as with typhoon Ida,a 55 millibar deepening was observed over an 18 hour period.Some typhoons go through more than one phase of intensificationor do not follow a simple intensification-decay cycle.
3. DATA:
Table 3-1 records the 1969 season verification ofmaximum wind forecasts at warning time and all forecast times.
Figure 3-1 is the 24 hour maximum wind forecast
3-1
verification for individual typhoons of 1969.
Figure 3-2 is the frequency distribution of errors for12, 24, and 48 hour forecasts of maximum winds.
Table 3-2 records the 1966 season verification forpurposes of comparison.
4. ANALYSIS :
During the first 48 hours of each forecast period in1969 absolute mean error increased at a mean rate of 2 knotseveryb~ hours from an initial error of 4.9 knots at warningtime. The algebraic mean error was minus in all time categoriesindicating a forecast bias on the low side. The low bias in-creased from 1.9 knots at warning time to 6~8 knots at 48 hours.
The largest intensity errors were associated with thetwo most intense typhoons (Viola and Elsie), together withTyphoon Ida whose rate of intensification was unusually rapidand with Typhoon Susan, an off-season typhoon that ignoredclimatology in reaching 105-knot sustained velocity. Onlythese four typhoons significantly exceeded the mean absolute24 hour forecast error of 13.7 knots.
The 24 hour intensity error distribution ranged from-45 to +35 knots with the median forecast 5 knots low andthree-fourths of the forecast errors falling between -25 and+15. The 48 hour intensity error distribution ranged from -55to +60 with the median forecast 5 knots low and three-fourthsof the forecast errors falling between -35 and +10.
It is evident fkom the appearance of the forecast errordistribution curves (Figure 3-2) that maximum wind forecasterror increases with time and shows little skill at 48 hours.The median 12 hour forecast is accurate within ~ 10 knots; themedian 24 hour forecast is accurate within + 37.5 knots.
In order to evaluate the relative success of thecentral pressure forecasting technique, the same analysis wasmade of the 1966 season accuracy of forecasting maximum winds.The results are reported in Table 3-2. Comparison shows asignificant improvement in 1969. This is attributed to in-creased emphasis on forecasting maximum wind velocity and theeffectiveness of the central pressure technique devised forthis purpose.
5. CONCLUSIONS:
Forecasts of maximum wind for 12 and 24 hour timeperiods in 1969 have mean absolute accuracies of 9.0 and 13.7knots respectively with a 5 knot bias toward underforecasting.These figures reflect a significant improvement over the 1966season and indicate that the procedure described in this sectionis effective.
3-2
6. ACTION:
Continued use of the central pressure method of fore-casting maximum winds is indicated for 1970 with an attempt tocorrect the tendency for slight underforecasting.
a. The algebraic mean values might suggest that fore-casts could be improved in 1970 by merely increasing all fore-casts by 5 knots, however, the frequency distribution in Figure3-2 shows a modal value at zero error. Simply displacing thecomplex curve five knots to the right would not improve thedistribution significantly. If the curve were pictured assymmetric with the errors on the positive side, the excess offorecasts in the range 10 to 25 knots too low becomes evident.
b. A study of these cases is indicated as the bestway to improve performance in 1970. A further improvementmay be realized from a climatological approach to mean ratesof intensification. The climatic average values for the seasonused as minimum intensification forecasts should reduce thenumber of underforecast cases and produce a slight positivebias in mean values with a better centralized distribution.
3-3
TYPHOONINTENSITYVERIFICATION
I ABSOLUTEMEAN ERROR (KTS) I ALGEBRAICMEAN ERROR (KTs)
FORECAST FORECAST
STORM WARNING 12-HR 24-HR 48-HR 72-HR WARNING 12-liR(CASES) (CAsES)
24-FiR(CASES)
48-HR 72-HR(CASES) (CASES) (CASES) (CASES) (cAsEs) (CASES) (CASES)
PHYLLIS 10.0 (21) 11.1 (19) 10.6 (16) 16.2 (12) 24.0 (4) -1.0 (21) + 4.7 (19) + 7.1 (16) +16.2 (12) +24.0 (4)
SUSAN 8.9 (21) 15.9 (19) 20.8 (21) 39.5 (13) 33.3 (4) -8.9 (21) -14.1 (19) -19.7 (21) -34.5 (13) -26.7 (4)
TESS 4.Q (lo) 9.3 ( 7) 13.8 ( 8) 25.0 ( 1) - (0) +1.0 (lo) + 6.4 ( 7) + 2.5 ( 8) +25.0 ( 1) - (6)
VIOLA 2.9 (24) 9.1 (23) 17.7 (22) 27.5 (16) 35.8 (6) -0.8 (24) + 3.5 (23) - 3.2 (22) -21.9 (16) -35.8 (6)
BETTY 2.0 (15) 7.1 (12) 12.7 (11) 9.2 ( 6) 15.0 (1) -0.7 (15) + 0.4 (12) 0.0 (11) + 9.2 (6) +15.0 (1)
CORA 1.0 (25) 3.2 (28) 7.4 (29) 13.2 (22) 15.6 (8) +0.2 (25) + 2.1 (28) + 2.9 (29) + 1.8 (22) - 5.6 (8)
IX3RIS 1.7 ( 9) 4.3 ( 7) 10.0 ( 5) 15.0 ( 1) - (0) -0.6 ( 9) - 4.3 ( 7) - 4.0 ( 5) +15.0 ( 1) - (0)
ELSIE 5.3 (31) 10.2 (28) 17.2 (30) 34.5 (22) 46.7 (9) -0.8 (31) : 0.5 (28) - 2.8 (30) 0.0 (22) - 3.3 (9)
GRACE 6.0 (29) 6.5 (23) 14.2 (25) 26.5 (17) 38.0 (5) -4.3 (29) - 2.6 (23) - 9.4 (25) -10.0 (17) - 4.0 (5)
HELEN 6.7 (15) I ~~.4 (14) 13.6 (14) 31.9 ( 8) 12.5 (2) -6.0 (15) -11.4 (14) -12.9 (14) + 0.6 ( 8) -12.5 (2)
IDA 4.8 (24) 12.7 (22) 18.9 (22) 31.6 (16) 55.8 (6) -4.0 (24) - 7.3 (22) -13.4 (22) -30.3 (16) -55.8 (6)
JUNE 5.6 (27) 8.5 (24) 9.3 (27) 10.3 (18) 17.1 (6) 0.0 (27) - 3.1 (24) - 5.6 (27) - 9.2 (18) -15.7 (7)
KATiiY 3.2 (22) 8.3 (20) 10.0 (18) 12.1 (14) 11.0 (5) +1.4 (22) + 5.3 (20) + 7.2 (18) + 3.6 (14) - 7.0 (5)
ANNUALTOT?LL 4.9 (273) 9.0 (246) 13.7 (248) 22.9 (166) 30.2 (57) -1.9 (273) - 1.4 (246) - 4.2 (248) - 6.8 (166) -13.3 (57)
TABLE 3-1
ANNUAL TOTAL
TYPHOON
ABSOLUTE
INTENSITY VERIFICATION
1966
MEAN ERROR ALGEBRAIC MEAN
24-HR 24-HR
17.2 KTS —3.4 KTS
TABLE 3-2
ERROR
3-5
INTENSITY FORECASTING SKILL 1969
30I
28 -II
26 t
24I
12HOUR ~22 24 HOlJR -----
Ii
‘“48HoUR ~
20
18 1
L I \
\lll
z 16 f II.Ll I: 14I.LlCL fli
12 A I
;1:
10 A/“ a ‘ I t
8 f % 0 I0 I
6 ir
#f k
44 I,/
I\
\$
2 4 I \
e ●’ I-
‘ %.I
-45-40 -35 -30 -25 -20 -15 -10 -5 0 +5 +10 ,15 .20 ,25 .30 ,35 ,4D .45
FIGURE 3-2
B. A Discussion of Tropical Cyclone Forecast VerificationMethods and Seasonal Differences in Forecasting Difficulty.
1. GENERAL :
a. Mean Error: The verification method for tropicalcyclone forecasts used since the establishment of JTWC hasbeen mean absolute error, with the 24 hour error receiving themost attention. (See Figure 4-1)
b. Right Angle Error: Recognition of some basic in-adequacies of the mean absolute error led to addition of theright angle error charts (See Figure 4-3) to depict trackforecasting Aility apart from speed errors.
c* Median Error: Occasional large forecast errorscontribute disproportionately to the annual mean error as seenin Figure 3-3. All mean values are greater than their cor-responding median values. In 1969 the median error for theover 200 MI cases was 265 MI. Six errors of 70 MI are neededto balance 200 MI errors. The extreme effect of this could beseen in 1960 when multiple storms? overtaxed reconnaissanceresources and erratic tracks combined to produce more largeforecast errors and resulted in a spread of 46 N.M. betweenmedian and mean values. Median error provides a more con-servative and meaningful measure of forecast accuracy for theseason. Since median error represents the 50 percent confid-ence level, any desired specific and significant point in thefrequency distribution of errors (67%, 75%, 80% or 90%) couldbe selected as a more valid measure of skill than the meanabsolute error. The few large forecast errors that do occurwould contribute equally to the combined figure on a one fore-cast-one vote basis. It is interesting to note that both 1968and 1969 median scores of 97 N.M. were records for the 11 yearperiod of record.
d. Seasonal Differences: The increased differencein 1969 between the median score of 97 N.M. and the mean scoreof 111 N.M. illustrates the influence of a few large errors onthe annual mean in a “light” typhoon year. The 1968 and 1969seasons both had six recurving typhoons and a similar number ofopportunities for large error during recurvature or on northeast-erly accelerating storms even though the total number of warn-ings issued in 1969 was only about half of the 1968 total.Through midseason 1969 including Typhoon Doris the JTWC absolutemean error was 89 N.M. The influence of recurving TyphoonsGrace, Helen, Ida, June, and Kathy was not balanced by anystraight-running, late-season cyclones. The year ended witha respectable but disappointing 111 N.M. mean error. Thepotential for breaking 100 N.M. in mean error for a seasonremains good but depends on limiting the larger errors and thechance occurrence of well-behaved cyclones. This illustratesa basic difficulty in evaluating forecaster performance fromyear to year in the tropics. A sample of 100 tropical cyclonesmight constitute a representative sample of all situations
3-8
24 HOUR MEAN AND MEDIAN ERRORS
180-FOR JTWC TYPHOON FORECASTS
MEAN ~ _ –170MEOIAN ~
160
150 ‘
140aiJi
130
120 F
110
100 i
YEAR
FIGURE 3-3
faced by the forecaster at one time or another, but a one-season sample of 20 or 30 cyclones is liable to contain adisproportionate number of recurving or erratic cyclones,resulting in a relatively high mean error. A sample contain-ing straight-running cyclones, on the other hand, would producea cushion of better than average forecasts. A method of evalua-tion including a measure of forecast difficulty would providea more realistic appraisal of forecaster performance.
e. Displacement as Measure of Difficulty: A skill-scoring method sometimes mentioned for extratropical storms isbased on error as a ratio of actual displacement during theforecast period. This method was used by LCDR Jerry Jarrellof Naval Weather Research Facility to examine JTWC annual fore-cast verifications from 1959 through 1967. (unpublished) Thestudy has been updated for 1968 and 1969 and is presentedgraphically in Figure 3-4. The assumption made in this approachwas that if a cyclone moves 500 N.M. in a 24 hour period, anerror of 100 N.M. shows more skill than if the cyclone movedonly 250 N.M. in the same period. In this system forecasterrors are expressed as miles of error per mile of movementrather than the usual miles of error per 24 hour time period.In,the first case the error rate would be 100/500 or .200.The error rate of the second example would be 100/250 or .400.
An implication of this system applied to individualforecasts is that slow-moving storms are easier to forecastthan fast-moving storms. Such is not alwyas the case, asillustrated by recurving storms which execute the greatestchange of direction and present the most difficult forecastingsituation while moving at their slowest speed. The error-producing combination of deceleration, rapid change of directionand then acceleration challenge the ability of any forecaster.Even though the 24-hour distance moved in a recurve track isthe same as that on a straight track, the recurving storm isa much more difficult one to forecast. A quasistationarystorm could never score well in the system because of thesmall denominator in the skill ratio. An excellent verifica-tion error of 50 N.M. made while the storm only moved 75 mileswould not appear to have much skill. Applied to yearly meanvalues the system may avoid objections raised on the basis ofindividual forecasts. In the application of this techniqueto JTWC forecasts the mean displacement value and mean errorare used to produce mean error ratings for each year. Thevariability of individual years in mean displacement values isevidence of significant differences in mean storm behavior fromyear to year. Under this rating system the 1969 season witha mean 24-hour speed of 12.4 knots for all typhoons would bemore difficult to forecast than the 1968 season when a mean24-hour speed of 9.2 knots was recorded. Compared with thepast 11 years the 1969 season ranked 1st in difficulty and1st in accuracy by the mean error to displacement ratio.
f. Objective Technique Scores as a Measure of Dif-ficulty: A second indication of basic differences between
3-1o
NM290
280
270
260
250
240 I
230
220
210
200 ‘
MEAN ERROR TO DISPLACEMENT RATIO
RATIO.90
.80 \
.70
.60
.50
An.Tu
.30
.20
.1024 HR ERROR/ DISPLACEMENT RATIO =======
YEARFIGURE 3-4
seasons is the variability noted in extrapolation and Arakawaobjective technique scores in Table 3-3. The samples used inconstructing the table included forecasts for tropical cyclonesof all classes. (The JTWC values in this sample therefore maydiffer from official verification figures which include onlythose cyclones reaching typhoon strength.)
EXTRAPOLATIVE TECHNIQUE SCORES
YEAR
1967
1968
1969
JTWC EXTRAP
121 NM 136 NM
103 NM 108 NM
121 NM 131 NM
ARAKAWA
NOT USED
119 NM
137 NM
TABLE 3-3
Extrapolation as used at JTWC includes a consider-able amount of subjective judgement by the forecaster. Theextrapolation forecast is usually the starting point for eachofficial forecast. The fact that official forecasts have im-proved upon intelligent extrapolation by 5% in 1968, 9% in1969 and 11% on a small sample in 1967 indicates a consistentmean skill on the part of the JTWC forecasters to do what theypurport to do-forecast typhoon movements. A function of thedifference between extrapolation error and mean error mightserve as a measure of forecaster skill and JTWC performance.The Arakawa technique has consistently proved to be the bestof truly objective techniques. This method eliminates the sub-jectiveness of extrapolation and may reflect the differencesin difficulty between seasons better than any other simple method.The technique is firmly based in extrapolation. Errors record-ed by this technique should be a good measure of the amount ofnonsteady state change occuring. The 1969 mean Arakawa errorof 137 N.M. compared to the corresponding 1968 value of 119 N.M.is interpreted to indicate that 1969 cyclones were more ir-regular in movement than those of the previous year, a factwell supported by personal observation.
2. CONCLUSIONS:
a. An objective means of rating the difficulty of atyphoon season should be considered in addition to the singlevalue of mean or median accuracy. The Arakawa technique isfavored for this purpose.
b. Median scores should be included in future annualreports as an alternate measure of forecast accuracy.
c. The error to displacement ratio is not consideredan indicator of forecasting skill, but displacement serves topoint out the differences in storm behavior between one seasonand another.
3-12
c. Frequency Distribution of Error in JTWC Official Fore-casts.
1. BACKGROUND :
Operational use of JTWC tropical cyclone warningsrequires an appreciation of the frequency and nature of fore-casting error likely to be encountered. This article is aneffort to describe the frequency distribution to form a real-istic basis of understanding for both the operational user andthe JTWC forecaster.
2. PROJECT SCOPE AND DESIGN:
Mean 24-hour absolute errors on all storms designatedas typhoons from 1959 to the present were counted and totaledby 10-knot intervals. The total frequencies were graphed anda smooth-curve analysis made (See Figure 3-5). A total of4236 forecasts were included in the study. In order to providean operationally useful tool the individual interval totals wereconverted to cumulative percentages for two periods: 1959-1967and 1968-1969. (See Figure 3-6.) It is difficult to estimatewhether the improved performance of the last two or threeseasons can be maintained in future typhoon seasons. Bothcurves have been presented to show the long-time and recentexperience.
3. DISCUSSION:
The cumulative percentages on the Y-axis can be usedas desired levels of confidence to find the error margin inN.M. associated with this confidence level on the X-axis.
CONFIDENCE TABLE
LEVEL 59-67 (NM) 68-69 (NM) IMPROVEMENT
50% 118 97 17.8%
67% 162 126 22.2%
75% 186 147 21.0%
80% 206 164 20.4%
90% 260 220 15.4%
TABLE 3-4
3-13
(dI
FORECAST ERROR FREQUENCY DISTRIBUTION 1959-1969
300. T
280 -
260 d \r
240 7
220 L
200 1 L
180
160 A
140 7
120’ r \
1oo- A
80 * \
60 F
40 L
20
IQ 23 3444 5Q 6CJ7Q 8Q 9_0100110120130140150160 170180190200210220230240 25026027028029030031(
TOTAL ERROR (NM)
FIGURE 3-5
t ,
CUMULATIVE PERCENT OF FORECAST ERRORBY MILES OF ERROR
1-=Eawa
FIGURE 3-6
4. CONCLUS IONS:
It is noted that even though median and modal scoreshave rea~~ed record accuracies in 1968 and 1969, they don’tmeasure the full extent of the forecast improvement realized.The maximum improvement is recorded near the one sigma levelwith over 22% improvement made in two-thirds of all forecasts.
b. The area of major improvement in the curve wasbetween 40 N.M. and 160 N.M. and in this area represents a30 to 40 N.M. increase in confidence level.
c. The failure to limit large errors is evident asthe 90% and greater confidence levels are entered. Less im-provement has been made in the upper 10 percent than in theaverage forecast range.
d. The incidence of errors exceeding 200 N.M. hasbeen reduced from 21% to 12% but remains the necessary areaof concern both because of the disproportionate influence onmean values and the potential for severe weather damage dueto lack of adequate or timely warnings.
e. Very little improvement has been realized in theupper 5%. About 15 or 20 forecasts per year are so unpredic-table that 24-hour errors will exceed 300 N.M.
f. In addition to this graphic approach to confidencelevel, the nature of each forecast situation should be con-sidered. A storm moving in a northeasterly direction is, forinstance, less accurately forecasted than other situations.
3-16
D. Causes and Cures for Forecast Errors Exceeding 200 N.M.
1. GENERAL:
A study of errors over 200 N.M. for the 1968 seasonwas made to determine contributory factors and identify areasof possible improvement.
It was noted that the individual characteristics ofeach storm predispose large forecasting errors. Eleven ofthe 20 typhoons of 1968 had no forecasting errors greater than200 N.M. The nature of each storm is, however, more a matterof hindsight rather than an evident feature of a storm priorto onset of looping, acceleration or generally erratic move-ment. Errors over 200 N.M. occur during all phases of thelife cycle of tropical cyclones. In 1968 the early phases ofa storm accounted for one-fourth, the late phases for one-fourth and the mature stage for the remaining one-half oflarge errors. The six identified factors contributing tolarge errors were:
a. Forecaster Technique 1/6
b. Misleading Recon Data 1/6
c. Lack of Recon Data 1/6
d. Looping Motion or Quasistationary Periods 1/6
e. Acceleration on Northeasterly Track 1/6
f. Unusual Motions to Southwest or SharpRecurvature etc. 1/6
Fujiwhara motions would also result in large errorsbut have not been common in 1968 or 1969.
Improvement of individual forecasts in the six cate-gories is the present subject of JTWC operational research.The study of forecaster confidence reported in this annualpoints up the basic inability of the forecaster to anticipatelarge errors in many situations. Even under those circumstanceswhen he can recognize the potential for large error, he is ableto limit his error to average values in only half of the cases.
A forecaster’s handbook for JTWC is being prepared asan aid to improve forecaster technique in minimizing theseerrors, particularly those resulting from misleading recon-naissance data.
The lack of reconnaissance data during the first 12 to18 hours of warning of many developing storms is common. Whena daylight investigation locates a depression, continuousreconnaissance is generally planned for the following morning.If the cyclone is moderately well developed when first located
3-17
or forecasted to develop rapidly, fixes are requested as soonas possible. During the initial period of development pre-diction of the direction of movement of tropical cyclones isfrequently not very successful. Only after two or three“fixes” are we able to state with good confidence where thecyclone is or is going. The selection of the initial trackis made on the basis of climatology, synoptic steering, andvarious objective techniques. Because of aircraft schedulingproblems and the need to place cyclones in warning as soon astheir development can be predicted, only small improvement canbe expected in this area in the future.
Looping motions are a two-edged sword to forecastingaccuracy. The sometimes sudden deceleration finds two orthree forecasts far overshooting the storm and a consequentacceleration out of the loop leaves two or three quasistation-ary forecasts far behind. A study of loop duration, exitspeeds and directions and a means of anticipating the breakoutwill be undertaken to provide a degree of error reduction inthis difficult situation.
A study of accelerations on northeasterly tracks revealsa persistent underforecasting of northeast movements during1968 and 1969 as well as in many years past. The average 24hour error for northeasterly moving storms in 1968 was 156 N.M.on 52 cases. The 1969 average of 127 N.M. for 45 cases wassome improvement, but forecasts remained persistently behindactual acceleration. During 1969 ten of forty-five northeast-erly forecasts were in advance of actual movement, none by morethan 65 miles. In 1968 ten of fifty-two forecasts were inadvance of actual movement, six of them on the same storm andthree of these 160 to 180 N.M. in advance of actual movement.
The experience of 1968 and 1969 is being used to ident-ify storms with an expected accelerating track to the north-east and to compensate for the persistent underforecasting ofmovement seen in past years in 1970 operational forecasting.
The final category of movements to the southwest, sharprecurvatures and other unusual actions will continue to pro-duce a few large errors. The best hope for improvement in thesestorms that fail to follow extrapolation may be found in theanalog technique now under development.
A follow-up study in 1969 found that three typhoonsaccounted for 72% of the 24-hour errors over 200 N.M. and allof the 24-hour errors exceeding 300 N.M. Elsie, Grace andJune were the misbehaving ladies. Elsie settled down after arather unpromising beginning but Grace and June remained erraticthroughout their lifetimes.
3-18
E. A Comparison of Objective Techniques for Typhoon Movement.
1. STATUS :
Forecasts using seven different objective techniqueswere used and verified for all four warning times for all 24hour forecasts issued by JTWC in 1969. Techniques showing thebest results in 1968 were retained and those failing to showpromise were discontinued.
2. 24
a.
b.
c.
d.
e.
f.
9“
HR OBJECTIVE TECHNIQUES:
JTWC - official forecast for comparison.
EXTRAPOLATION - a semi-objective method by whichforecast points are determined by recent pastvalues of position, speed and direction.
ARAKAWA - grid overlay values of surface pressureare entered into regression equations and handcomputed.
700 mb PROG - HATRACK forecast based on 700 mb SRforecast fields.
700 mb PROG MOD (12 Hr) - (d.) is modified by twicethe recent 12 hr vector error.
500 mb PROG - HATRACK forecast based on 500 mb SRforecast fields.
700/500 mb PROG RENARD - method using HATRACK 700 mblongitude and HATRACK 500 mb latitude (reported in1968 annual).
3. MODIFICATION TECHNIQUES:
a. A single correction vector equal to twice the mostrecent 12 hour error correction vector is applied to the 700 mbprog forecast to produce the 700 mb prog mod forecast.
b. A 12 hour history position is provided as an inputto the TYRACK program. The apparent speed and direction overthe past 12 hours is computed and used to select the best steer-ing level and to correct the forecast steering of that level forobserved differences from history.
4. TESTING AND RESULTS FOR 24 HOUR FORECASTS:
A homogeneous sample of 210, 24 hour forecasts, fortropical storms and typhoons was assembled for 1969. ResU1tsare summarized in Table 3-5. The following general observationsare offered:
3-19
STORM (CASES)
T. PHYLLIS (13)
T.S. RITA ( 3)
T. SUSAN ( 5)
T. TESS ( 3)
T. VIOLA (14)
T.S. WINNIE ( 3)
T.S. ALICE ( 2)
T. BETTY ( 9)
T. CORA (25)
T. ELSIE (23)
T. GRACE (25)
T. HELEN (14)
T. IDA (20)
T. JUNE (25)
T. KATHY (17)
T.S. LORNA ( 9)
ANNUAL MEANVALUES (210)
* 700PROG MOD (12)
OBJECTIVE METHODS STATISTICS 1969(24 HR MEAN VECTOR ERRORS N.M.)
JTWC
150
60
74
134
93
120
195
108
88
78
186
184
88
140
146
129
124
EXTRAP
160
56
99
96
127
100
222
115
85
97
254
242
94
138
139
156
142
ARAKAWA
154
54
63
66
129
108
243
118
87
94
337
215
86
123
144
108
144
TABLE 3-5
700P 700P*
183
540
333
314
232
266
123
246
187
225
292
406
138
170
240
268
235
230
162
282
150
161
267
121
57
222’
158
116
100
168
201
154
500P
379
320
398
232
194
242
171
255
198
238
398
342
122
244
354
314
272
RENARD
160
542
291
338
207
296
171
276
198
228
278
361
129
141
192
218
221
TYRACK
175
292
252
90
177
182
276
250
113
267
505
337
271
205
240
150
251
has only 124 cases. Comparisons cannot be made on ahomogeneous basis-between this and other objective methods. Many of themissing forecasts involved extreme forecasts and were omitted as not mean-ingful.
3-2o
a. JTWC official forecasts are again significantlybetter than any single objective technique.
b. Extrapolation continues to be the single most re-liable objective technique. The 1969 extrapolation error of142 N.M. increased 28 percent over the 1968 value of 111 N.M.The improvement over extrapolation of the JTWC official fore-cast increased from 5 percent in 1968 to 13 percent in 1969.
c. Arakawa forecasts remain very close to extrapolationand increased 16 percent over the 1968 value of 121 N.M.
d. The HATRACK 700 mb prog again verified better thanthe 500 mb prog but total error of 235 N.M. is excessive.
e. The 700 mb prog mod (12 Hr) - again improved onthe performance of the unmodified forecast with performanceapproaching that achieved by the Arakawa surface pressuremethod.
f. The 700/500 mb prog Renard method again improvedupon the performance of both the 700 mb and 500 mb HATI?ACKforecasts by 7 percent over 700 mb and 19 percent over 500 mb.
9“ The TYRACK forecasts were disappointing in totalaccuracy but provided the most realistic and usable track fore-casts during the season, particularly for recurving storms.Large speed errors continue and show need for additional programcontrols. The continued improvement in 48 and 72 hour rightangle error is in part due to guidance from the TYRACK trackforecast.
h. Individual forecasts in a non-homogeneous samplewere examined from the viewpoint of determining the forecastmethod producing the individual absolute best verificationscore. The results are presented in Table 3-6.
BEST INDIVIDUAL OBJECTIVE FORECASTS
JTWC EXTRAP ARAKAWA 700P 700PM0D 500P RENARD TYIWCK
#TOP 76 49 66 11 29 15 14 34
CASES 282 279 265 235 134 227 224 256
RATE .270 .176 .249 .043 .217 .066 .063 .133
TABLE 3-6
The JTWC forecast does not always produce theabsolute best forecast but is more consistent. Cases whereextrapolation or Arakawa produced a best forecast often in-volved a difference of only a few miles from the official fore-cast. Mean deviation from the JTWC forecast in these cases was
3-21
48 N.M. for extrapolation and 53 N.M. for Arakawa. This pointsout an area of potential improvement since 115 of 282 casescould have been improved by closer use of extrapolation orArakawa objective techniques. Since all forecasts begin withextrapolation the remaining 167 forecasts must represent situa-tions where extrapolation was correctly modified to produce abetter official forecast. Further research aimed at develop-ing procedural rules for limiting the deviation from Arakawaand extrapolation should improve some of the 18 cases in whichthe JTWC error was over 100 N.M. greater than extrapolation orArakawa.
i. Tables 3-7 and 3-8 present stratified analyses of1969 objective methods. Table 3-9 applies stratification bylatitude to JTWC official forecasts. The 1969 sample is notlarge enough to guarantee representative figures in all strati-fications but most results support previous observations. Thefollowing tentative conclusions based on stratification areoffered:
(1) All ccq?uter mthcxk except the 700 mb progmodified for 12 hour error performed best at higher latitudeswith northeasterly moving storms. Arakawa did not work wellat all for tiese storms. Extrapolation error was high due toacceleration. The 700P(MOD) provided a fair overall forecastfor northeasterly moving storms.
(2) The most forecastable storms were those southof the ridge l~ne. JTWC, Arakawa and extrapolation scored beston these. The 102 N.M. error for Arakawa on 77 westerly movingstorms is very convincing.
(3) Stratification by wind extensity shows im-proved steering with increased intensity for all except theextrapolative techniques.
3-22
OBJECTIVE FORECAST STRATIFICATIONERRORS BY DIRECTION OF MOVEMENT
001-0900
JTWC 152 (44)*EXTRAP 179 (44)ARAKAWA 231 (44)700P 197 (44)700P (NOD) 168 (30)500P 205 (44)RENARD 187 (44)TYF@CK 224 (44)
091-259°
226 (15)246 (15)218 (15)307 (15)186 (lo)457 (15)299 (15)249 (15)
260-300°
98 (74)110 (74)102 (74)262 (74)150 (39)290 (74)247 (74)260 (72)
* Cases shown in parens
TABLE 3-7
OBJECTIVE FORECAST STRATIFICATIONERRORS BY INTENSITY
MAX WINDS <50 KT ~50 KT
JTWCEXTRAPARAKAWA700P700P(M0D)500PRENARDTYRACK
132130128286186295277282
(60)(60)(60)(60)(26)(60)(60)(59)
121146151215146263198239
(150)(150)(150)(150)( 98)(150)(150)(149)
* Cases shown in parens
TABLE 3-8
OFFICIAL JTWC FORECASTSTRATIFIED BY LATITUDE
24 HR 48 HR
SOUTH OF 20N 103 (132) 202 ( 63)20iN to 30ii 117 ( 96) 240 ( 82)SOUTH OF 30N 109 (228) 224 (145)NORTH OF 30N 134 ( 20) 330 ( 21)ALL CASES 111 (248) 237 (166)
301-360°
113 (77)130 (77)121 (77)218 (77)143 (45)258 (77)200 (77)259 (77)
ALL WINDS
124142144235154272221251
72 HR
305 (16)346 (31)332 (47)429 (10)349 (57)
* Cases shown in parens
TABLE 3-9
3-23
F. Confidence Forecasting.
1. BACKGROUND:
Forecaster confidence in his product is an often dis-cussed parameter. If a forecaster were able to anticipate hisgood and bad forecasts, operational users would benefit fromthis information. In response to discussions of the 1969Typhoon Conference an operational research project was designedto record and evaluate the accuracy of forecaster confidenceat the time of forecast at JTWC.
2. PROGRAM SCOPE AND DESIGN:
The confidence forecast sample was 205 separate con-fidence forecasts from April through October of 1969. Thesample included tropical storms as well as typhoons. TheDirector, Operations Officer or Typhoon Duty Officer completeda series of objective and subjective forecasts of confidenceafter each official warning but prior to the next aerial recon-naissance fix. The objective methods used were:
a. Area Climatology of Errors Based on Mean 1968Experience: The assumption of this approach is that the dif-ficulty of forecasting can be predicted from the location ofthe cyclone at the time of forecast.
b. Area Climatology by Category: This approach usedthe same data base as the first but makes only the categoryforecasts of average (110 N.M.) below average (70 N.M.) or aboveaverage (150 N.M.)
c. Mean Climatology: A representative mean climatologyof 110 li.M. was applied to all forecasts.
d. Persistence: The 24 hour error determined at fore-cast time was forecasted to persist for the next 24 hours.
e. Subjective Forecast: Forecaster confidence inthe subjective feeling a TDO has about his knowledge of wherea cyclone is now, where it has been and where it is going. Thefollowing values were suggested from the 1968 season:
1st three warnings (no good 12 hour history) 150 N.M.
20 to 30 knot winds at forecast time 120 N.M.
Northeasterly movement 140 N.M.
Best confidence limit 40 N.M.
Worst confidence
The original
limit 200 N.M.
impetus for this study was the understand-
3-24
able desire to express statistically the increased confidencethat was believed to accompany the reduction in forecastingerror noted in the last few years thus enabling closer passageby mobile operating forces to tropical cyclones when forecasterconfidence was better than average.
3. ANALYSIS:
a. General: Only the subjective method was significant-ly better than the other four methods tested. On the whole,forecasters’ subjective estimates tended to be conservative,averaging 9 N.M. greater than observed mean error. Seventy-five percent (75%) of the confidence forecasts verified witherrors no more than 20 N.M. greater than the forecast value.This figure compares with seventy-six point-five percent (76.5%)that would have verified under the same ground rules using amean error value of 105 N.M. for all forecasts. The secondmethod approximates the manner of applying confidence impliedin current SEVENTH FLEET Operations orders and presents afair argument for retention of the present doctrine.
The relatively poor performance of the error fore-casts by geographic area of origin is undoubtedly due in partto the limited sample size of the error climatology. Whenever1968 error history was not available the mean value for 1968was substituted. The relatively poor final performance of thearea climatology, both mean values per 2 1/2 degree squareand three category assignment, indicates negative correlationbetween forecast errors in the same geographic location fromone year to the next. A tentative hypothesis for these datais that geographic errors are less significant than dynamicerrors associated with storm intensity, speed of motion,direction of motion and its relation to large scale synopticfeatures of current weather charts. The expansion of errorclimatology based on geographic area would eventually producea forecast showing some skill due to a concentration of stormswith similar characteristics in the same area, but a moredirect approach considering the dynamics of intensity or speedand direction of motion should be superior meteorologically.
The poorest of the objective methods is the per-sistence forecast. The results here indicate that large errorsor small errors are unlikely to repeat themselves over a 48hour period and also that forecasting of extreme values resultsin larger errors than forecasting mean values. We must concludewith some conviction that yesterdays performance is less in-dicative of todays confidence than is last years mean errorvalue.
Even though the mean value of subjective forecasterconfidence shows little skill over last years single mean value,the possibility of skill in one or more confidence categoriesis worth investigating.
3-25
b. Better Than Average Confidence (25 N.M. or less):Forecasts of good confidence are useful if (1) they can bereliably made and (2) they can result in a significant changein operational decisions. Relative to the first criterion,12 of 49 confidence forecasts (24% of better than averageconfidence (85 N.M. or less) verified with greater than averageerror (135 N.M. or more.) From this we might describe a 76percent confidence level that our forecast of “better thanaverage” will verify as “average” or “better than average.”Relative to the second criterion the best confidence used dur-ing the period was 50 N.M. The median error of the confidenceforecast was 42 N.M. ~ operational decision at the 75 percentconfidence level would thus involve the difference between asingle mean error of 105 N.M. and the adjusted subjective fore-cast of 92 N.M. A maximum reduction of a “clearance criterion”for tropical storms of only 12 percent or 13 N.M. would result.my of the 12 “bust” forecasts from the “better than average”forecast group might have encouraged a closer approach thanwould otherwise be considered prudent to the subsequent trackof a typhoon if the confidence forecast were used in deter-mining an evasion course. It is doubtful if the potentiallysmall gain justifies the loss of confidence level.
c. Average Confidence (90 to 130 N.M.): One hundredfive (105) of the two hundred five (205) forecasts in the samplewere forecasted to be in the average range (90 to 130 N.M.)and only 21 of them (20%) verified with greater than averageerror. One would normally expect many more “bust” forecastsfrom the average confidence group than from the better thanaverage group if predictable skill were involved.
d. Below Average Confidence (135 N.M. to 200 N.M.):Twenty-four (24) of fifty-one (51) below average confidenceforecasts (47%) verified correctly in the above averageerror group suggesting considerable skill in the recognitionof large error potential at the time of forecast. Even whencircumstances of missing or questionable data create doubtin the forecasters mind and lead him to anticipate large poten-tial errors, persistence works toward verifying a conservativeextrapolation forecast. Verification of an expected largeerror with better than average accuracy is no indication oflack of forecaster skill. On the contrary it indicates thata difficult situation was recognized and correctly forecasted.The greater frequency of large errors in cases where they areexpected would be valuable information to the Captain desiringto exercise all caution due an uncertain forecast of hazardousweather.
4. CONCLUSIONS :
a. Confidence as a forecast parameter is subject tothe same range of inaccuracies experienced with other forecastparameters.
3-26
b. The best method of forecasting confidence found inthe initial project was the subjective opinion of the fore-caster.
c. The only occasion when a subjective confidenceforecast showed significant skill was when large errors wereanticipated.
3-27
G. - Fujiwhara Effect - Case Studies.
1. INTRODUCTION :
There are many problems to be faced in tropical cyclonemovement forecasting. One of these, which occurs only seldombut which is capable of injecting exceptionally high errorsinto movement forecasts, is the interaction of vortex centerswith one another. This is often referred to as a demonstrationof the Fujiwhara effect in honor of the first primary investi-gator of this phenomenon. This interaction or Fujiwhara effectis characterized by a cyclonic rotation of two vortex centersabout some point located along a line connecting their twocenters. This rotation is usually co-existant with a mutualattraction of the two vortex systems. The combined effectsof rotation and attraction greatly affect forecast accuracy,since cyclone behavior deviates sharply from normal underthese conditions.
Before forecast improvement can be achieved throughpractical application to compensate for the Fujiwhara effect,a better understanding of cyclone behavior under influence ofbinary interaction is necessary. To aid in this understanding,research was conducted on two cases of previous cyclone inter-action. These cases were picked at random with the hope ofobtaining cases representative of most occurrences.
Individual cyclone movement was investigated to seeif it was feasible to combine cyclone rotation rates and someform of translation of a point common to both cyclones toobtain a reasonable estimate of actual individual cyclone speedof movement.
The first case investigated was that of Typhoons Kathyand Marie during the period 14/00002 through 19/00002 August1964 (See Figure 3-7). The second case was that of TyphoonsMarge and Nora during the period 24/12002 through 28/12002August 1967 (See Figure 3-8).
The first case appeared to be a more classical exampleof binary cyclone interaction than the second case, but therewas a definite interaction of the two cyclones in the secondcase also.
2. PROCEDURE:
The two cyclone tracks within each case were plotted onthe same chart so that a visual representation of their relativeinteraction could be observed. Lines were drawn between eachof the cyclone tracks connecting locations at correspondingtimes, so that angles of rotation could be determined. Amidpoint between the cyclones along each connecting line wasdetermined.
3-28
Though the use of the midpoint as the rotation pivotis a very simple method, it does not consider relative sizesof the interacting cyclones. Therefore a second set of rota-tion points was obtained to include a relative size factor.Many authors have theorized that rotation during binary cycloneinteraction occurs about a point corresponding to the center ofmass of the two interacting systems. Mass of any meteorologicalsystem is a very vague term and one which is hard to define.To incorporate this theory into an actual study, a previouslysuggested method using a maximum wind speed ratio was utilizedusing the following formula;
DV2dl=~+ V2 [11
where
dl is the center of mass location fromcyclone 1.
D is the total separation distance of thetwo cyclones.
V2 is the maximum
VI is the maximum
wind speed of cyclone 2.
wind speed of cyclone 1.
By using these two points, the midpoint and the centerof mass point, rates of rotation were determined. Afterwardthe translation speeds of these points of rotation were addedwith the rotation speed in hopes that a good approximationof actual cyclone speed could be determined. A twelve hourtime period was used for all calculations. The followingformulae were used:
s ‘Sr+St
Sr = 1.4X10-3 d~ (for 12 hour
‘t = D*/12 (for 12,hour
where S: total speed of movement
Sr:
St:
d:
z:
D*:
speed of movement resulting
speed of movement resultingof the point of rotation.
[2]
period) [31
period) [4]
from rotation.
from translation
angle of rotation over the 12 hour period.
the average radius of rotation.
distance point of rotation moves in 12 hours.
3-29
NOTE : Direction ofto the direction ofcalculated movement
3. DISCUSSION:
An analysis
movement ofthe cyclonespeeds.
the point of rotation relativerotation was not considered in
of the movement speed calculated by boththe center of mass and the midpoint methods showed that ingeneral the computed speed of movement was more accurate forthe northernmost cyclone. The computed values for speed ofmovement for the southernmost cyclone were generally too high(See Figures 3-9 and 3-10).
One cyclone investigated, Typhoon Nora, fit these generalobservations but the calculated speeds were exceptionally un-realistic up to 27/00002. After that time calculated valuescompared favorably with the actual cyclone speed. At that timeNora became the northernmost cyclone of the pair and also beganto show a slow intensification. This large error was probablycaused by the fact that prior to 27/00002, Nora was just form-ing and moving very slowly. Her strength was only 20 knots orles$ during this period and she appeared to be no more than aweak, but well organized, tropical low.
Investigation of Case I (Typhoons Kathy and Marie)indicated that for Typhoon Kathy the center of mass point ofrotation method gave exceptionally good results for the entireinteraction period with an average error of only 1.5 knots.This was an average percentage of error of 27%. For Kathy themidpoint method gave good results also with an average errorof 2.5 knots representing an average percentage of error of 36%.
For both methods, one time period was characterized byan unreasonable error. Estimated speeds for Kathy during the12 hour period 17/12002 to 18/00002 were calculated as 7.5knots and 7.1 knots for the center of mass method and the mid-point method respectively. During this time period Kathy wasmoving south, becoming the southernmost cyclone after previouslybeing the northernmost cyclone. During this time the directionof rotation was perpendicular to the point of rotation move-ment therefore the rotation speed alone should have given thebest estimation of the actual movement speed. The rotationspeeds for the center of mass method and the midpoint methodwere 5.6 knots and 6.8 knots, respectively. These compared morefavorably to the actual movement speed of 4 knots.
The average results for Typhoon Marie were comparableto the results obtained for Kathy with an average error of 2.7knots when the midpoint method was used. This correspondedto an average percent of error of 32.9%. When the center ofmass method was used a much greater average error of 5.9 knotsand an average percent of error of 60.6% was obtained. A lookat Figure 3-9 shows that after 17/00002 the errors for themidpoint method decreased and remained fairly accurate. At thatsame time the center of mass method increased in accuracy but
3-30
after 18/OOOOZ the accuracy decreased significantly. It wasfound that for every time there were poor comparisons the cyclonewas either moving at large angles to or in the opposite directionto the movement of the rotation point. ‘i’hisindicates that acomponent of the point of rotation movement speed relative tothe direction of movement of the cyclone should be consideredin order to achieve the best results.
It was also observed that the original northernmostcyclone actually slowed to a minimum movement speed about 6 to12 hours after the calculated speeds of both the midpoint andthe center of mass methods indicated a minimum in speed. Atthe time the two interacting cyclones became east and west ofeach other the cyclone moving south tended to slow sharply inmovement while the cyclone moving north began to accelerate.Shortly before this the point of rotation either slowed inmovement speed or became erratic in movement.
Investigation of Case II (Typhoons Marge and Nora)indicated that the midpoint method gave slightly better resultsfor both cyclones considered together, but neither method gavegood results for Nora until 27/00002. As mentioned earlier, be-fore this time Nora was only a weak developing tropical low andas such her movement is considered unrepresentative of normalcyclone movement under Fujiwhara effects.
Excluding the results for Typhoon Nora, the comparisonof actual versus computed speeds of movement for this casecompared favorably with those of Case I. The speeds of movementcalculated for Typhoon Marge indicated that the center of massmethod gave slightly better results for the overall investigatedtime interval. The center of mass method gave an average errorof 2.3 knots as compared to 2.5 knots for the midpoint method.The corresponding average percents of error were 31.2% and 38.7%,respectively (See Table 3-10). The midpoint method gave except&on-ally good results during the first part of the investigationperiod up to 27/12002 with an average error of 1.0 knots andan average percent of error of 8.4%. Both methods were verygood until 27/OOOOZ.
After 27/00002, Marge became the southernmost cycloneas the two cyclones slowly rotated. After that time the cyclone’smovement was perpendicular to or in the opposite direction ofthe rotation point movement. This case, therefore, also indi-cates that more accurate results could be obtained by using thecomponent part of the rotation point movement corresponding tothe cyclone movement.
Although Nora was very weak during the initial timeperiod of this case study, she evidently had some definiteinfluence on the movement of Typhoon Marge. Nora was too weakin comparison to Marge to ever cause a full rotation but Shewas able to alter the track and speed of Marge (See Figure 3-8).At the time when Nora moved north of Marge’s 0900 bearing,attraction of the two cyclones seemed to cause a rapid decelera-
3-31
tion of Marge and shortly thereafter Marge experienced a changein direction to a north of west course.
As noticed in Case I, the points of rotation for Case IIslowed in movement or changed direction abruptly approximately6 to 12 hours preceding a decrease in the speed of movement ofthe cyclone moving toward the south. (See Figure 3-10.)
The angle of rotation (=) is one of the major vari-ables contributing to the estimation of a cyclone speed ofmovement while experiencing Fujiwhara effect. Since little isknown about what elements cause significant changes in valuesof @ , a short investigation of its characteristics evident inthese two case studies was conducted. It appears that thereis some influence on ~ caused by changes in intensity differencesof the two interacting cyclones and changes in the averagedistance of separation. An investigation of this variance ofti in relation to values of intensity differences compared withcyclone separation indicated that an increase in w occurs witha decrease in separation distance and an increase in the in-tensity difference of the two cyclones. It also appears thatvery little rotation occurs at separation distances greaterthan 600 or 700 N.M. no matter what the intensity differenceis. See Figure 3-11.
4. CONCLUSION:
The results of this research indicate that cyclone speedof movement during interaction can be closely approximated bytheoretical calculations which combine the rotational effect ofthe cyclones and the translation of the point of rotation.
Results were exceptionally good when the cyclone wasmoving in the same direction as the point of rotation. Itwas also noticed that when a cyclone was moving in an oppositedirection to that of the rotation point better results wereachieved by subtracting the translation speed of the rotationpoint. For inbetween cases, such as when the cyclone was mov-ing at angles to the direction of movement of the rotation point,calculated speeds would be improved by adding or subtractingonly that component of movement speed of the rotation pointthat corresponded to the direction of movement of the cyclone.
Consideration of cyclone intensity by using the centerof mass method was necessary only for cases of excessive dif-ference in the intensity of two cyclones. Even for excessiveintensity differences the midpoint method will generally givesatisfactory results.
By using the translation of the point of rotation asa contributor to the cyclone speed of movement, we are assumingthat the speed of movement of the rotation point is in directproportion to the steering flow. We are also assuming thatthe steering flow is homogeneous for the entire rotating system,which requires the horizontal shear to be zero. This is a
3-32
tenuous assumption since horizontal shears are seldom zero overan area as large as that representing these rotating systems.Therefore it must be concluded that the presence of excessiveor large horizontal shears can definitely inject significanterrors into speed calculations.
It was noticed during analysis of computed cyclonemovement speeds and the corresponding actual cyclone movementspeeds that at the time the points of rotation began to slowin translation speed or became erratic in movement, the cyclonepairs reacted much in the same manner for both cases. At thetime the point of rotation began to slow or became erratic,the cyclone moving toward the south slowed in movement withinthe following 6 to 12 hour period while the cyclone movingnorth began to increase in speed of movement within the next6 to 12 hours. After firm substantiation by investigation ofseveral more cases, this observed reaction could prove bene-ficial in the short range forecasting of changes in cyclonespeed of movement of two interacting cyclones.
There are definite possibilities for future use ofbinary cyclone interaction theories for assisting in fore-casting movements of interacting cyclones but considerablymore research is needed before a reliable forecast tool evolves.From equations [2], [3], and [4], we can see that if Sr andSt can be predicted with reasonable accuracy for a period oftime, say 12 hours, then an average speed of movement of thecyclone can be obtained for that 12 hour period. Keep in mindthat a component of St would have to be added or subtractedfrom Sr, depending upon an estimated direction of movement forthe cyclone in question. It appears that a reasonable answercould be reached simply by adding St to Sr for a westwardmoving cyclone and subtracting St from Sr for an eastward mov-ing cyclone.
Now that the use of the predicted Sr and St is necessary,we come to the perplexing problem of how a prediction of Sr andSt can be reached. Although not researched in this study, itappears that a reasonable value for St could be reached by steer-ing the rotation point with the integrated steering flow muchas would be done for forecasting the movement of a single cyclone.(The possible errors in using this method were suggested earlierwhen discussing the assumption of a horizontally homogeneousatmosphere over the interacting system). Prediction of St isdifficult enough but the prediction of Sr at this state of theart is even more difficult. From equation [3} it is noticedthat a value for Sr is dependent upon the angle of rotation fora predetermined time period (=) and u~on the average radius ofrotation (r). A reasonable value for r can be reached by fore-casting the expected distance separating the two cyclones,considering mutual attraction, and if desired, by also usingan estimated intensity of each cyclone. A prediction methodfor - is the major “weak link” in the chain. Present know-ledge of the mechanisms causing significant changes in therotation rates remains at a rather primitive level.
3-33
It may be possible in the future to obtain a reasonableapproximation for the angle of rotation from a graph similarto that in Figure 3-11. For this to be feasible, investigationof many more case studies will be required to increase thedensity of data points to obtain consistently reliable estimatesof the angle of rotation.
As a result of this investigation, it is definitelyindicated that cyclone movement during interaction can not befully explained or forecasted by the use of simple techniques,but continued research in this area has good potential forassisting in lowering errors in the forecasting of tropicalcyclone movement.
MOVEMENT ERROR (CALCULATED VS. ACTUAL)
MIDPOINT CENTER OF MASS
Average Average Average AverageError % Error Error % Error
CASE I Kathy 2.5 kts 36.0% 1.5 kts 26.5%
Marie 2.7 kts 32.9% 5.9 kts 60.6%0
CASE II Marge 2.5 kts 38.7% 2.3 kts 31.2%
Nora 7.7 kts 223.5% 11.4 kts 361.5%4
TABLE 3-10
REFERENCES:
1. Annual Typhoon Report, U. S. Fleet Weather Central/JointTyphoon Warning Center, Guam, 1964 and 1967.
2. Brand, Samson, Interaction of Binary Tropical Cyclonesof the Western North Pacific Ocean, NAWEARSCHFAC TechnicalPaper No. 26-68, Norfolk, Vs., 1968.
3. Riehl, H., Tropical Meteorology, McGraw-Hill Book Company,Inc., New York, 1954, Pg. 345-347.
3-34
vw.vln
y
wm
.,,-.”!,.. lZ% ,,,. ,?,.’”NE‘:,s 404.
37...-
36
““H’’’lH:”’’l”+’“I!2zEH-1-+-d P+-F---v”rzr
‘W.. I [ E I I I I :?
m’““m28. 11 1 A%:
CENTER OF MASS . ......MIDPOINT ‘-----mSPEEO OF MOVEMENT
*
r ‘LPL +U “+J<i- ,,
//
/—/
.
.. —.
——.,
./
.
! 90 Kii,. . . .IN KATHYC” !
E
.
/’/
/
/—
,,, ,
,0. 4,LA..S2,m, .,,. OU.,m
y’.mw..i! o,,
o ‘T
80Z-N
A,m
m:!
.r—-e—
~—
—----
---—
—~~.
wE.+--I
.!‘.
1–\+
&-
HiF
F+
”.i””--+-”--i”+
~:-f””#-F-w
&iY
i-Pf
-
l“.
VT
”-?Sn
7’Tr-’z’m
l!!-
22
20
u-)+1 8x
16i-Z~; 4
z~12
>010
E
LL8o
6
8W4
0-W*
o
28
26
24
22
20
38+’x
‘1 6
EZ,4
;12
>
;10
~8
o
n6IJLL14
%2
o
TIM$5,mPERlc)),2 (GMT)1a# 1+;2 1yom 1 t5g2 1 ;&03 1 7/12 181C0 18T~214/12 15 /00 1%2 16;%0 16/12 17,00
TO17[7? 18100 18T$2 19(OC
KATHY
.--~ ]-\
/,, ....-..’ ——.\
/~ l--/ -i/ ““...,\ / + L
/.+, ,,,. .,.. . . .
/ 1 / .....-.--’-”’”””
$ ~[’
“.., \... \<
/:/ .“
\
[ \ /\ ,~ :’
..../
.,. ....”
=.- / ......... ,. .....(p
ACTUAL$------$ MIOFOINTc------~ CENTER OF MASS
TlM:5mpER[~5~2(GM:~m::%& 1:g2
:?{;1712
yj: A17$2
15 /00 1%2 1+%!! 1:$2 181cx3:%:
1903
,,,..-.. )
MARIF ,.,$...,,
./....’6)-x------CY >‘.., .,..’
.,.$ ‘... ,,,”... z....,..’ ....”....’ ,..,’
,,,,..” ...’‘;,
t) ,’~------n -. i: ....’ ------,:’ JY ,: )
,,~ ‘\\ ((! / /’ ‘\ Y1.,.“., i
,,. /’ \\~\...” )~ “ \<\% ) ‘,:’;
\;\,...”, [@ /{!” AL\:\
/9A / .\-
//c~
/‘. /=--_u ,~A ACTUAL
0——•___::_~ MIOFQINTMASS
FIGURE 3-9
22
20
Gt-1 8x
16
1.L13
o6
c1
~4
II(J-J2
o
28
26
24
22
-20
K’Y
1-Z
8
6
TIME PERIOD (GMT )24;&2 2w# 25Jj2 26{.$ 26{&2 2 $/:0 2 q~2 28T~W
2!5[00 75 17 76 /00 76 /17 ? 7/00 77/17 7s[nf) 7s/1?
MARGF
.............,., h......,......”
=-[ 1<
“,\ -.—.\. 1..
/-- r[1
,..A ,/’ ,..
/./
,,.
./. ..
...”...... (...
.. %......-””””
L
A~ ACTUAL❑ —-—-a iw4DmlNT. . . . . . . . . . . . . . . 0 (_F NTFR OF viASS
TIME PERIOD (GMT)2;g2 2m# 2722 2 f5#c 261i12 271CQ 27112 27~oo
25100 25/12 26/00 26/12 2 7/00 2%2 2& 28 11?
...-...””
NORA...’
....’.,-,
...”’
c’...’
,,.,“
....’
J,/cl
A—A0———0 d0--0 CENTER OF MASS
o I I I I I I I I
FIGURE 3-10
I
3-38
Sl)i
r33
N3&
13dd
laA
11S
N31
NI
?~ 10
3C
o
\—
—
L.— ...
m——
./
●✍
●✍
�✎�
/
I
‘--?.—I -13
——
H. Climatology
1. TYPHOON FREQUENCY:
Typhoon frequency climatology was slightly decreased bythe small number of occurrences experienced this season. Theaverage annual typhoon frequency decreased from 20.6 at the endof the 1968 season to 19.9 at the end of this season (see Table3-11) .
2. TYPHOON DISTRIBUTION:
Figure 3-12 depicts the typhoon distribution of 347 ty-phoons which have been detected over the past 18 year interval.Notice that the months of high formation probability remainthe months of July through November after the inclusion of 1969typhoon data.
3-40
TYPHOON I’REQUENCY11 YEAR PERIOD
YEAX JAN I’EB im.u APR NAY JUIJ JUL AUG SEP OCT Nov DEC ANNUAL TOTAL
1959 0 0 0 1 0 0 1 5 3 3 2 2 17
1960 0 0 0 1 0 2 2 8 0 4 1 1 19
1961 0 0 1 0 2 1 3 3 5 3 1 1 20
1962 0 0 0 1 2 0 5 7 2 4 3 0 24
1963 0 0 0 1 1 2 3 3 3 4 0 2 19
1964 0 0 0 0 2 2 6 3 5 3 4 1 26
1965 1 0 I o 1 2 2 4 3 5 2 1 0 21
1966 0 0 & o 1 2 1 3 6 4 2 0 1 20
1967 0 0 1 1 0 1 3 4 4 3 3 0 20
1968 0 0 I o 1 1 1 1 4 3 5 4 0 20
1969 1 0 0 1 0 0 2 3 2 3 1 0 13
AVG .2 0 .2 .8 1.1 1.1 3.0 4.5 3.3 3.3 1.8 .7 19.9i \ \ ?
TABLE 3-11
IbPh)
18 YEAR MONTHLY DISTRIBUTION OF 347
80
70
60
50
40
301
20
10
0
W ES’ ERN PACIFIC TYPHOONS
1952 ~ 1969
m
m
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
*
FIGURE 3-12
1. Satellite Data Fix Accuracy.
1. BACKGROUND:
A study of satellite fix accuracy was presented in the1966 Annual Typhoon Report. Since that time a new generationof space hardware and improved technology have been developed.This study was made to reflect any improvements in terms offix data reliability.
2. METHOD:
Satellite bulletin fix positions were compared to theJTWC best track positions for the time of the satellite fixes.Results are reported in Table 3-12.
SATELLITE POSITION ERROR (N.M.)
1965 1966 1969
NUMBER OF CASES 75 71 75
AVERAGE ERROR 81 49 39
MEDIAN ERROR 55 39 34
RANGE OF ERROR O-425 5-219 5-105TABLE 3-12
3. CONCLUSIONS:
Slight improvement since 1966 is indicated, however,1969 figures were limited to storms whose best track windvelocities were 35 knots or greater. This eliminates the mainsource of disproportionately high errors during the formativestages and may account for some apparent gain in accuracy. The1969 mean and median position errors represent the practicaltotal resolution presently available from satellite systemsrelative to location of tropical cyclones.
3-43
CHAPTER IV
SUMMARY OF TROPICAL CYCLONES 1969
TROPICAL STORMS AND TROPICAL DEPRESS95. ,, 30 c row 10s, ,,0’
‘ ‘ -’ ;’”t~-——t -,---- ---t. 7“=!7 ‘? ,
120,,.i .=::,.
125. !30, !3Y 140. S4S. I 50’... . ., ., +-. D-.-7-+? ,.= , , ,. . . -- +. . . . . . 1
‘TA . I I
$M\ ‘‘—++-++++
‘P+y%,,,*,8,%T3w#
. a “+* -+--.lP , “, I ,,h.
,.,.- ,9! :.,,’
,,0.. .—--, +— . ..- --- ,,. ., ... _
,yA&i&~.{#” ‘~: +p”ql ‘~. ...4 .,. I. ,.. .,kid. .kid —L-, !. , ,. J., .. JL., ,,”., ,, ,,, ,”., ,– ;,:,..
INS OF1969__960, !65. 170. I 75. [..!, mm 100, ;,,! ,m!.r. I 75’
‘“’l”’’T ”l’’-”””-r’i”’ ‘7”:
,..: .. . . . . ,.r..:.r
,+J++:,++,.,..+’7+:-:+ i ;;+ ~,. .,..,. .,.,-...,.,<+
+ :‘“..$-+:’;~;t+:-:$; +–4-.
+ *+.._uM:_;,,;,,+;2,: g: :4,s, . ,$,,,, P ..,.
., .,. ..... ., ,, .,, ,,, ,,, ,,
,..,. ,..,, ..,,, .. ,,-.,~*.+__+,-+ *W
+-+ +- -+ -tMf-
. .
,60’
T’2-:-;-:<w“ I&-?’ !......%.:.
,,. . . ,, .,....,.+ -—+.,. ..,,
.,...,. .,..”,. ... ,1
+++ + 42.3+-+ v--i . . -+++.., w’ ‘ . . . . . ..
,. 10, I1O~“
~:- ~~~~~ / : ~~ ~~~~~ ~~~~~ .
,,0.”&*.
.-..+.+,—+. .
i..>%.%-.. .’=--= .7-
+–+–+4 - -F+lo, .-l ++0? ~ ; + ~ ‘“ w--i--i-+.l-t:’LI
‘:~~1“”“,!0’ ,“’, .”’
4...
I 1–+-+- –+. * u
e.:::..:~:.::::::;.‘!7
.$
?i.>~k ~ 1~1-1~ : :“’2
ml.,.,
u, ,%2. iw>-,,..,–. 2 . . . . ... . 1,, ..,..,.,, ,.-a.~ . . . .
,.I TYPHOONS OF 1969
175’,,. - ,W W,LW44 !7s. 170.
. ::,:p~-
,. ..7-.7 . . . .. ...=.,. . . .
!.
,40.. .+. +1-+---L- -,-.,40. !-- --- ,—+–+ +<
,W’’’’ ””” l.”
~~ Ii :
,,.
,.:
+$t - ..* _,. L _-
“! -!2) YI+!2,X . -..
. .
in+ -+–- -. ~++ .7+ !
,..
,. &’W:’ “,. ”
.
+--+ +-- ---+5&bx@+””J
“$ ,“~ ++ + + ++
-’%-4-.. ‘-4”-/. +4.xY.\.<::l\”ll”i”:l” $“!$ ! I “1”20
> . . ..llxJ\. J. %,. \L/L L. ..4. L .?:-, L.. .& . ...& .& . . . .
j:..++4k%~’”\’u” ‘!””+.t+tt+-+w-t+--&+.-.+ +.-4+++-+-4+W+++++--
+
.,.
&*
!,
+ Pf’1-- ~ -~ ‘~--t-’’tf%+i“+’”””+’ ““””
AtA-.d&.++++++ttt~ ++d?y,+.++,+..+. , L-+- ‘j+ww8 +.p+.-...l + .;--, L ,-+ ~ +--,
1. L. 1. .,%. L 1. ,1. .1“.ql ! \ , I ....
k+ I I l++ I ! +0
,
SUMMARY OF WESTERN PACIFIC TROPICAL CYCLONES OF 1969
During 1969, the Joint Typhoon Warning Center issued 430warnings on 13 typhoons, 6 tropical storms and 4 tropical de-pressions while in a warning status for 108 days. When com-pared with previous years, it is evident that 1969 was an un-usually inactive year.
There were no tropical cyclones passed to JTWC from out-side its area of responsibility and JTWC passed no tropicalcyclones to other agencies.
There were two “Super Typhoons” (maximum sustained surfacewind of 130 knots or greater) during the 1969 season comparedwith five in 1968 and four in 1967. Typhoon Elsie registereda 890 MB center pressure which is one of the lowest ever record-ed in the Western Pacific.
The following figures and tables are provided to presentrepresentative statistical data from the 1969 tropical cycloneseason and provide a ready reference for comparison with pre-vious years.
4-3
SUMMARY OF WESTERN PACIFICTROPICAL CYCLONES
OF 1969
1960-1967(AVE j
TOTAL NUMBER OF WARNINGS 781
CALENDAR DAYS OF WARNING 160
NUMBER OF WARIJING DAYSWITH TWO OR MORE CYCLONES 59
NUMBER OF WARNING DAYSWITH TH~E OR MORE CyCLONES 15
TROPICAL DEPRESSIONS 6
TROPICAL STORMS 11
TYPHOONS 21
TOTAL TROPICAL CYCLONES 38
,.
TABLE 4-1
SUPER TYPHOONS DURING 1969*
CYCLONE INCLUSIVE MAX -.NUMBER NAME DATES I~~ENSITy
1968—-—822
142
68
15
4
7
20
31
1969.—430
108
15
1
4
6
13
23
MIN MINSLP 700 MB llT
05 VIOLA 21 - 28 JUL 130 KNOTS 897 MB 2137 m
14 ELSIE 19 - 27 SEP 150 KNOTS 890 MB 2140 m
* Typhoons with maximum sustained surface winds of 130 knots orgreater.
TABLE 4-2
4-4
1969 TROPICAL CYCLONES
WARNINGS ISSUEDCALENDAR MAX MIN RADIUSDAYS OF SFC OBS SFC NO. AS
CYCLONE TYPE NAME DATE* WARNING WND* SLP CIRC TOTAL TYPHOONS
01
02
03
04
05
06
b 07I
ul08
09
10
11
12
13
T
TS
T
T
T
TS
TS
T
T
T
TD
TD
TD
T
. TS
T
PHYLLIS
RITA
SUSAN
TESS
VIOLA
WINNIE
ALICE
BETTY
CORA
DORIS
ELSIE
FLOSSIE
GRACE
17 JAN-22 JAN
07 MAR-09 MAR
18 APR-25 APR
08 JUL-11 JUL
21 JUL-28 JUL
29 JUL-31 JUL
02 AUG-04 AUG
05 AUG-08 AUG
14 AUG-23 AUG
31 AUG-02 SEP
07 SEP-11 SEP
07 SEP-08 SEP
11 SEP-12 SEP
19 SEP-27 SEP
29 SEP-05 OCT08 OCT-09 OCT
29 SEP-06 OCT
6 85
3 40
8 105
4 70
8 130
3 45
3 45
4 70
10 85
3 65
5 30
2 25
2 30
9 150
9 60
8 95
TABLE 4-3
966
993
943
974
897
984
982
962
948
973
990
996
996
890-..,
(,956,;.. .,
937
240
300
240
300
420
240
300
360
330
240
180
120
150
600
270
300
24 15
12 0
29 12
13 3
26 18
07 0
10 0
14 4
34 15
9 3
18 0
05 0
04 0
34 26
32 0
29 21
DISTANCE
1968
684
882
906
1854
480
678
1242
2226
612
648
174
216
2760
2598
2172
..-- ——-—--- ------ -. -—-. — . . . .lYb Y TRWPICAL CYCLONES (COnt ‘a)
MAx WARNINGS ISSUEDCALENDAR MAX MIN RADIUSDAYS OF SFC OBS SFC NO. AS DISTANCE
CYCLONE TYPE NAME DATE * WARNING WND* SLP CIRC TOTAL TYP1iOONS TRAVELED*
17 TD 30 SEP 1 30 997 120 02 0 42
18 T HELEN 08 OCT-12 OCT 5 105 930 330 20 10 2340
’19 T ‘“-IDA 15 OCT-22 OCT 8 115 917 360 26 17 1296
20 T JUNE 28 OCT-05 NOV 9 105 936 500 33 21 1782
21 T KATHY 03 NOV-08 NOV 6 110 930 420 24 19 2040
22 TS LORNA 24 NOV-28 NOV 5 50 985 360 17 0 582
23 TS MARIE 19 DEC-21 DEC 3 40 994 150 8 0 480
1969 TOTALS 108 430 184
*DATA TAKEN FROM BEST TRAcK
TABLE 4-3 (Cent’d)
r,. 4
1969 TROPICAL DEPRESSION POSITION DATA
WARNINGNO.
010203040506070809101112131415161718
DTG.—
070500ZO711OOZ071700Z072300Z080500ZO811OOZ0817002082300Z090500ZO911OOZ091700Z092300Z1005OOZ1011OOZ1017OOZ1023OOZ1105OOZ1111OOZ
WARNINGNO. DTG
01 072300Z02 080500Z03 O811OOZ04 081700z05 082300z
WARNIIJGNO. DTG
01 1111OOZ02 111700Z03 112300Z04 1205002
TROPICAL DEPRESSION ELEVEN07 SEP - 11 SEP
BEST TRACK POSITLAT LONG
19.7N 119.2E18*8N 118.8E18.2N 119.2E18.3N 119.6E18.8N 119.4E19.2N 119.3E20.ON 119.6E20.7N 119.9E21.5N 120.OE22.ON 119.9E22.4N 119.8E22.8N 119.8E23.3N 120.3E23.5N 121.OE23.2N 121.7E23.4N 122.4E23.lN 122.4E22.6N 122.2E
WARNING POSITLAT LONG
20.5N 119.OE20.3N 117.5E19.ON 118.OE18.ON 118.3E18.5N 119.5E19.ON 119.OE19.6N 119.OE20.2N 120.4E21.4N 120.lE22.4N 120.lE22.8N 120.2E22.5N 119.5E23.ON 119.8E23.9N 121.3E23.9N 122.5E24.ON 123.OE23.5N 122.5E23.lN 122.4E
24 HOURFORECAST POSITLAT LONG
19.7N19.5N18.5N17.4N18.5N18.7N19.lN22.ON23.4N25.9N25.8N
24.5N26.9N27.7N26.3N23.5N23.lN
112.9E111.3E115.5E117.4E119.5E118.OE117.6E121.3E120.6E121.9E121.7E
120.2E125.3E126.3E126.6E122.5E122.4E
TROPICAL DEPRESSION TWELVE07 SEP - 08 SEP
24 HOURBEST TRACK POSIT WARNING POSITLAT LONG IJIT LONG
13.5N 111.4E 13.6N 111.4E13.2N 111.OE 13.4N 11O.9E12.9N 111.3E 13.3N 11O.4E13.lN 112.lE 13.2N 109.9E13.8N 112.8E 14.5N 113.OE
TROPICAL DEPIU3SS10N THIRTEEN11 SEP - 12 SEP
BEST TRACK POSIT WARNING POSITLAT LONG LAT LONG
16.3N 130.6E 16.lN 130.8E17.ON 129.5E 16.8N 129.8E17.8N 128.7E 17.8N 129.OE18.8N 128.OE 18.7N 127.6E
FORECAST POSITLAT LONG
13.2N 108.6E13.ON 108.9E13.ON 108.3E12.9N 107.9E
24 HOURFORECAST POSITLAT LONG
19.7N 127.4E20.9N 127.OE22.lN 126.8E22.9N 124.9E
4-7
TROPICAL DEPRESSION SEVENTEEN30 SEP - 01 OCT
WARNINGNO. DTG
01 302300Z02 O1O5OOZ
WARNINGNO. DTG
01 070500Z02 O711OOZ03 071700Z04 072300Z05 080500Z06 O811OOZ07 081700Z08 082300Z09 090500210 O911OOZ11 091700Z12 092300Z
WARNINGNO. DTG
01 292300Z02 300500Z
24 HOURBEST TRACK POSIT WARNING POSIT FORECAST POSITLAT LONG LAT LONG LAT LONG
15.4N 118.5E 17.3N 118.OE 19.ON 117.OE15.9N 118.lE 16.5N 118.5E -
1969 TROPICAL STORM POSITION DATA
TROPICAL STORM RITA07 MAR - 09 MAR
BEST TRACK POSITLAT LONG
05.3N05.6N05.9N06.2N06.5N06.8N07.lN07.3N07.5N07.7N07.7N07.7N
168.9E168.2E167.4E166.4E165.4E164.5E163.5E162.5E161.5E160.3E159.lE157.9E
TROPICAL29 JUL
WARNING POSITLAT LONG
05.4N05.7N06.ON06.ON06.4N07.lN06.9N07.3N07.5N07.7N07.8N07.8N
168.6E167.4E165.9E166.OE165.6E164.5E163.OE162.8E161.6E160.4E159.4E157.7E
STORM WINNIE- 31 JUL
BEST TPJiCKPOSIT WARNING POSITLAT LONG LAT LONG
16.ON 133.4E 16.ON 133.5E17.2N 132.3E 16.6N 132.6E
03 3OO11OOZ 17.9N 131.lE 18.ON 131.OE04 301700Z 18.4N 129.6E 18.9N 129.6E05 302300Z 18.7N 128.lE 19.ON 127.9E06 3105OOZ 19.ON 126.8E 19.ON 126.7E07 3111OOZ 19.3N 125.8E 19.ON 126.lE
24 HOURFORECAST POSITLAT LONG
06.4N06.4N06.5N06.5N07.ON07.5N07.5N08.ON08.ON08.lN08.lN08.lN
162.7E161.5E160.OE160.9E161.3E159.5E157.9E158.6E157.OE155.7E154.6E152.8E
24 HOURFORECAST POSITLAT LONG
18.8N 129.7E.19.3N 129.2E21.2N 127.2E22.3N 126.2E22.7N 123.6E20.lN 123.3E17.7N 123.5E
4-8
CLlcdklwkalar.1.lr.d
-l$emo
cmm
mm
..00...
●I
KlcdGardElfdKiGlcdmrJJrdbawl
G.lwEaKIGacdMGaFdkl
I-lrimmme+fiommm
mm
wcom
mNm
l+FrNr-.
...0.●
.**#e
●*.*..
..**.*
Inwln-rw
olNom
olwti
mm
mm
lmlxm
m=
rr-ww
6J~mN~l’’JmNNmNm
fxe4mltvNrNlw
mloJoJm
JmF
I!-!I+I+I-I?-11-I?
-IAI+A
?-4
?-iA
l-lrll+i-lr-il-lrlr-lrlrl
Zzzzzzzz
wo~
m?-im
eo●,.*,,
..
Inwm
oolmw
bO
JCvmm
mm
mm
Zzzzzzzzzzzzzz
Zzzzzzzzzz
I--amlnw
oer-mr-lw
mO
mlnl+
olmlm
(vmm
oo...........*
......
.,...0
r-om
mo
ul+el-lsln
qmlnm
mln-yw
-=r=$ulm
ml-io
Jmc.Jm
tNm
mtN
rueJF
4Ncw
Nmm
eJmr.Jm
lvmlm
I
klkardG.LdKIE-lKlrdkl
Wltlco
lnd
l-mw
lnco
G.lwriirdmrilfilr.drdrawwr.dr.il
,QKlklrdriicdrdblwklklwm
InO
mco
=rcn-m
om
mm
=r~mm
mm
mm
m-
+Ww
qm●
.*.*..,0...
...0
...0
0...
..*.
...**.*,.
r.tQlnu-llrl*-Yw
-3ulm
mm
mm
mm
mm
mA
1-ldr-11-lt+d
t+r+rl
Zzzzzzzzzz
-Or-l-loonlaulm
●****.
,,.0
F)w
wl-co
mo
c-iNm
CN
mm
txr-lr.lrnro
lnm
Zzzzzzzzzzzzzz
Zzzzzzzzzz!zzz
m~m
r-lwm
mbm
-lrlfaw
l+mo
lncN
o!6Jm
com
co(ncnw
m‘&WklEIKik!MGalilcdEl
020mulm
wem
mcn
●.****
....
Fbtou)lnwqqw
mtim
mm
mm
mm
mm
d!-id
dl-11+1-11-fd
ri
.0.00..
..
..
..*.*.,
..
..
..
,**
m~wm~mm+m-l!+
‘2JOJ(w
lwm
mm
mcla=r
U-)u)qt-+r-lm
clm(vm
mm
lmm
olm
mSlolm
lcur+m(volm
cwolm
lNine-l
1+1-ir+rld++l+f+r-ldrl
1++1-11+1-il-i!-it-l+rll-ieiI-II-It-i
Zzzzzzzzzz
I-r--mo
om
mm
mw
●✎
☛☛
✌✌
●☛
✎☛
m-m
t=com
o+m
mN
m(vcW
@J(N
mm
mm
NNNNNNNNNN00000000000000000000m
dfim
m~r-m
tnd
O+elm
lol-leim
lo!i
mm
tww
mm
mm
ew
INNNNNNNNNNNNNNNNNNNNNN
NNNNN0000000000
Ooaom
maeac)
aaoo
o00’00000000000
0000000000000000—
—-
——
——
mm
+r-mm
dh
mm
d~m
md
t-mm
d~m
m+b
mm
d0101-11-lcw
orld
cwo
+I+m
lol+l+m
od
rfmo
i-1rlNo
t-1tn
oo
oo
dd
+f+m~
Nm
mm
mm
-r-r=ywm
mm
mco
mtw
mm
mm
oo
oo
o00000000000000000
0000000000
rl’mlm
=ru)w
i-mcn
o000000000.+
+mm
qm
w~m
mo
dc4m
dIm
h91-w
mo
dm
fnem
wr-
Oo
oo
oo
oo
oi++
F1l-tl-lf+f-ir+f-if-im
l(’um
rJr.40101N
WARNINGNO. DTG
28 081700Z29 082300Z30 090500Z31 O911OOZ32 091700Z
WARNINGNO. DTG
0102030405060708091011121314151617
2411OOZ241700Z242300Z250500Z251100251700Z252300Z260500Z2611OOZ261700Z262300Z270500Z2711OOZ271700Z272300Z280500Z2811OOZ
WARNINGNO. DTG
01 1911OOZ02 191700Z03 192300Z04 200500Z05 2011OOZ06 201700Z07 202300Z08 2105OOZ
TROPICAL STORM29 SEP08 OCT
BEST T~CK POSITLAT LONG
28.9N 135.5E31.lN 137.8E34.ON 141.8E37.3N 146.5E41.ON 151.OE
TROPICAL24 NOV
BEST TRACK POSITLAT LONG
09.9N 133.lE10.4N 132.6E10.9N 132.lE11*6N 131.7E12.2N 131.3E12.9N 131.3E13.5N 131.5E14. 3N 131.6E13.7N 131.7E13.5N 131.3E13.7N 130.9E14.lN 130.6E14. 4N 130.lE14.5N 129.6E14. 8N 129.2E15. 3N 128.9E15.7N 128.6E
TROPICAL19 DEC
BEST TRACK POSITLAT LONG
15.2N 141.7E16.2N 141.4E17.lN 141.2E17.9N 141.3E17.8N 142.3E18.3N 143.6E18.9N 145.lE18.ON 144.4E
FLOSSIE (Cent’d)- 05 OCT- 09 OCT
WARNING POSITLAT LONG
29.ON 135.4E30.8N 137.6E34.7N 140.8E37.4N 146.3E41.3N 150.2E
STORM LORNA- 28 NOV
WAPJJING POSITLAT LONG
09.8N10.3N10.8N11.5N12.4N12.6N13.4N14.5N14.2N13.3N13.9N13.9N14.4N15.5N16.4N14.8N16.3N
132.9E132.6E132.lE131.7E131.2E131.OE131.5E131.5E131.8E130.7E131.lE130.7E129.5E128.6E128.2E129.5E128.5E
STORM MARIE- 21 DEC
WARNING POSITLAT LONG
15.3N16.3N17.lN18.5N17.8N18.3N19.ON17.8N
141.7E141.lE141.3E141.OE141.6E143.3E145.2E143.OE
24 HOURFORECAST POSITLAT LONG
36.4N 142.OE41.ON 143.3E
24 HOURFORECAST POSITLAT LONG
11.2N11.9N12.8N13.5N15.4N15.2N16.2N18.2N15.5N14.8N13.9N13.9N16.lN19.8N20.2N16.5N
129.lE129.6E129.4E129.7E130.2E130.2E131.9E132.3E132.7E131.3E131.lE130.7E128.lE128.4E128.6E128.5E
24 HOURFORECAST POSITLAT LONG
19.2N 140.3E20.3N 140.9E19.9N 141.3E22.7N 143.7E20.lN 142.7E21.2N 146.7E
4-1o
Forecast positions for the 24, 48 and 72 hour forecastsare verified only as long as the best track analysis estimateswinds in excess of 33 knots for tropical cyclones which reachtyphoon intensity.
In addition to this method of verifying absolute error dis-tance, a computation of closest distance to the best track (rightangle error) has been included to indicate the demonstrated abil-ity to forecast the path of motion without regard to speed.
The following tables and figures are presented to graphicallydepict the distribution of forecasting error in JTWC forecasts.
FORECAST VERIFICATIONAVERAGE mmo~ (NAUTICAL MILES)
1950-5819591960196119621963196419651966196719681969
24 HR
170*117
177136144127133151136125105111
48 HR
---*267
354274287246284303280276229237
72 HR
------------
476374429418432414337349
*FORECAST POSITIONS NORTH OF 35N WERE NOT VERIFIED.
TABLE 4-4
4-11
JTWC OFFICIAL FORECAST ACCURACY
N.M.
500 ‘
475476
450429 432
425 — 72 HR.
400
375 v3s4 374
350
325 337
300 “303
275 r 374267
250 T246225 I 229
200 I24 HR. 177
175 170 A
150151
125 136 136
127
100n7
105
75
50
25
00 50-58 59 60 61 62 63 64 65 66 67 68 698
FIG 4-1
FORECAST ERROR TABULATION - 1969
MEAN ERRORCASES (N.M.)
24 Hour
Whole SampleBelow 20N20N - 30NBelow 30NAbove 30N
48 Hour
Whole SampleBelow 20N20N - 30NBelow 30NAbove 30N
72 Hour
Whole SampleBelow 20N20N - 30NBelow 30NAbove 301?
24813296
22820
16663
1::21
5716314710
111103117109134
237202240224330
349305346332429
TABLE 4-5
4-13
DISTANCE BETWEEN OPERATIONAL WARNINGPOSITIONS AND BEST TRACK POSITIONS
NUMBER AVERAGE MAXIMUM MINIMUMOF DISTANCE DISTANCE DISTANCE
CYCLONE WARNINGS (NM) (NM) (NM)
1. T. PHYLLIS 24 16 45 012. T.S. RITA 12 26 87 083. T. SUSAN 29 14 39 034. T. TESS 13 29 150 005. T. VIOLA 26 16 42 026. T.S. WINNIE 07 20 37 087. T.S. ALICE 10 19 55 068. T. BETTY 14 15 45 059. T. CORA 34 14 52 05
10 ● T. DORIS 09 11 19 0311. T.D. 18 42 118 0612. T.D. 05 50 128 0513. T.D. 04 20 27 1714. T. ELSIE 34 17 61 0415. T.S. FLOSSIE 32 19 60 04
T. GRACE 29 35 128 03;$: T.D. 02 82 118 4518. T. HELEN 20 20 88 0519. T. IDA 2.6 15 59 0320. T. JUNE 33 17 71 0321. T. KATHY 24 19 80 0422. T.S. LORNA 17 29 104 0623. T.S. MARIE 08 28 82 05
1969 SEASON 430 20.7 150 00
TABLE 4-6
4-14
TYPHOON
PHYLLISSUSANTESSVIOLABETTYCORADORISELSIEGRACEHELENIDAJUNEKATHY
TOTALCASES
MEANERROR
1969 AVERAGE
24 HR FORECASTSCASES ERROR
16210822102905292514222720
248
9161
16899
107776392
186123
87139145
111
FORECAST ERRORS
48 HR FORECASTSCASES ERROR
12130116062201221708161814
166
14011036018124320348
176429438176267338
237
(MI)*
72 HR FORECASTSCASES ERROR
0404
060108
090502060705
57
220184
167330405
316715420288319498
349
* INCLUDES FORECAST ERRORS DURING TROPICAL STORM INTENSITY.
TABLE 4-7
4-15
—I
1OacoaIAo
4@?
h?@
.
4-16
TYPHOON
PHYLLISSUSANTESSVIOLABETTYCORADORISELSIEGRACEHELENIDAJUNEKATHY
TOTALCASES
MEANERROR
1969 RIGHT ANGLE FORECAST ERRORS(CLOSEST DISTANCE (N.M.) TO BEST TRACK)
24 HR FORECASTSCASES ERROR
16 5221 4608 9422 6310 4529 5805 5429 4625 11714 5422 7227 5820 79
248
65
48 HR FORECASTSCASES ERROR
12
130116062201221708161814
166
8891
268109
97180
48102188
18132123209
130
72 HR FORECASTSCASES ERROR
0404
060108
090502060705
57
129178
11133
349
151265
65200173409
209
* INCLUDES FORECAST ERRORS DURING TROPICAL STORM INTENSITY.
TABLE 4-8
4-17
RIGHT ANGLE ERROR
5256
0 --- \
N.M.
27!
25(
I72 HR. ’35 \
225 229~zog!
200 211I
175172
48 HR.
150
125138
I100 I I
I 8224 HR.
75
I71 64
b~
50 I25
Ioo~ 1965 ‘1966 ‘1967— 1968 ‘1969d
FIG 4-3
,
CHAPTER V
INDIVIDUAL TYPHOONS OF 1969
NOTE . See Appendix A for definitions or clarification of wordsor phrases that appear in this chapter.
TYPHOON PHYLLIS - 01/17/0500Z TO 01/22/2300Z
I. DATA
A, STATISTICS1. NUMBER OF WARiiINGS ISSUED - 242. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 153. DISTANCE TRAVELED DURING WARNING PERIOD - 1968 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 966 MBS AT 1821OOZ2. MINIMUM OBSERVED 700 MB HEIGHT - 2819 M AT 1821OOZ3. LMAXIMUM SURFACE WIND - 085 KTS (FROM BEST TRACK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 240 f41
II. DEVELOPMENT
A. INITIAL IMPETUS - LOW LEVEL SURGE INTO CYCLONICCIRCULATION FROM THE SOUTH WITH SUBSEQUENT DIVERGENCEAT 200 MB LEVEL.
B. INITIAL SURFACE VORTEX1. EMBEDDED VORTEX AT 140000Z2. SURFACE PRESSURE LESS THAN 1006 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - SOUTHEAST2. UPON REACHING TYPHOON INTENSITY - SOUT}lEAST
III. FINAL DISPOSITION
A. DISSIPATED OVER WATER
5-1
w
A
+.. r :’:- ““-‘“- ‘“- “’”-““ “, ,:; ,.J’s”:“. w -....”: -’. - -- -.. q’.- -., . ---- ---- -- -.. ~~~
u 1
/. .1..T’,j- -“”’” -o’’””- ‘“’”’” ““”- ‘“””- ““”- ““”- ““””--, . ...,,...,
,.,.,;.+..}.+..+.7 --130 30 ~, 30 34 t-+--+---– *W..+ . ...+. -+._...+
H - - -- -:: rr - “ 1 ~
.,. .d ,, ””” “’”’ ‘“” “’” ““”
. -,,
..- -.. .- -.. .- -.. .- -.. .- -,. . . ,...
~o 130’ 14Ls. Iw Iw BEST TRACK,M,. . . . . -. . ..- -. @..- -....- -,.,,- -.,.- -. .,’.- -, 17cr
9i6 ?‘~i:$bw 25; ; ; ‘“””” - ‘WW’!M” - ‘“’”- -’”’;” -:;’:” -;;;;- -;:;:- -,;;:TYPHOON PHYLLIS
f +-t-t+ Q 17-22 JAN 1969,a !,srwo J!UA
.&. - -’- -.”- -’”- -’”%- -’”’- -“’””” ‘“’”- ‘“”’”
CYCLONE 01,.. --.. ,-, .,,, rn,~z --- -- --- -..
r
mI
LA)
18N
16N
14N
12N
ION
OtFn
TYPHOON PHYLLIS 21105 Z
CYCLONE 01 >,
BLOW UP *
20/17Z-21/llZ JAN 1969/
20/23Z 21’112
mG SPEED INTENSITY
20/172 8 6520/232 6521/05z ; 6521/llz 11 55
:
:
142E 144E 146E 148E~
150E 152E 154E 156E 158E ~
11
11
11
11
11
1II
IIII
III
II
IIll
8I
II
I1
81
2111-
11
11
1111Ill1
11
3>3
-L-V
U
IllIllIllIII
.2,3
.>
-TT
z.-ii-,M~
,3.2
w-u
-u.+
.
31111tall
III:
II
1II
III
II
II-1
II
III
dz.-L1
3
II:Ill1
1%
Ilz
IllII
II
IIlllllilI
III
II!1
11
11
11
11
InntillIzllI
(1
Itll1
11
11
1!1
11
11
It
II
II
I!-u’u
II
II
tI
l++
\\\\\\\=.\
1)
II
II
IN-O
.XJ1I
I1
1fsl
II
1-
-1I
II
t1
=1
II
1-
\~\\\\\\\\\
\\~
II
II
IIf-1
1=1
-*
1A
L1
I1
s1L
.-1..
II
+1
-1I
II
1I
,U1-11
II
I\\\\\\\\\1
t-lcl
1t
II
,.-..-..,*
II
I1
Ial
I0
1=
I!
II
l-uI
)J
.t-fI
II
I1
>1
Im
tll.=
x‘-u
-u
c
Illlf1
11
11
11
11
1
IT)=
,~...
I>D‘-u
-u
Ir-s,ntnzn.
‘n-+
-lax,n
1I
II1
=1
II
II
IIIx
llI
1I
1II
1=)
I1
Ld
.L1
x
5-4
11
11
.1r_121111zli_171
.<<31
L~
<-IIJ!11I
Izl.?3
1d-l.-
1ra
i3-
IIIIllIll
JJ
ztlllll>T
llllllJ
J3
11
11
11
J-t
I
III
●III
I11.ztlt
.L
II1(
II:
11
11
11
11
11
11
;1
11
:11
Ollll!f)ll
11
+lo
-11
-J-1
11
1’u
llItw
l!wl
J>\
l\\\\\\\\\\\\
k-1
1-:
ltlmll
lfolm
l.
..-..0.,-,
,-..
11
11
11
11
11
11
ItllllIllltl
Ill(It
1(1
:11
Ww
,wl.d
wid
klw
wtd
uW
wn
--l’T
l--)cm
I)O
e*e*(lJ
Ix.
..
..
..
..
..
..
5-5
UIi
m
WARNNO.
%0304
:?)0708
09101112
13141516
17181920
DTG
17050021711OOZ17170021723002
18050021811OOZ18170021823002
19050021911OOZ19170021923002
20050022011OOZ20170022023002
2105OOZ2111OOZ21170022123002
WARNING POSITLAT LONG——
08.7N 171.OE08.9N 169.8E09.2N 167.7E09.3N 166.OE
09.5N 164.3E09.7N 162.5E10.7N 160.5E11.lN 159.2E
11.5N 158.OE11.8N 156.9E12.3N 1S5.2E12.8N 153.6E
13.4N 152.OE13.6N 151.4E14.lN 150.OE13.8N 149.8E
13.8N 149.4E14.2N 149.8E12.9N 148.9E13.4N 146.4E
TYPHOON PHYLLIS
TROPICAL CYCLONE 01 -- 01/17/11002 TO 01/22/17002POSITION AND FORECAST VERIFICATION DATA
BEST TRACK 24 HR FCST 24 HR ERROR 48 HR FCST 48 HR ERROR 72 HR FCST 72 HR ERRORLAT LONG LAT LONG DEG DIST LAT LONG DEG DIST LAT LONG DEG DIST— — . — — — — —
08.9N 171.3E09.lN 169.5E09.2N 167.7E09.3N 165.9E
09.7N 164.lE10.1N 162.4E10.7N 160.8E11.lN 159.3E
11.5N 157.9E11.9N 156.4E12.4N 154.9E12.8N 153.6E
13.3N 152.4E13.8N 151.3E14.ON 150.3E13.7N 149.7E
14.2N 149.9E13.5N 149.9E12.8N 148.7E13.3N 146.7E
09.5N 165.4E09.7N 163.8E10.ON 161.4E09.7N 159.8E
10.2N 157.6E10.3N 155.71212.8N 154.lE13.ON 153.8E
12.9N 152.9E13.lN 152.lE13.6N 150.5E14.5N 147.8E
14.9N 147.OE14.8N 147.5E14.9N 146.OE14.9N 146.2E
14.3N 147.7E14.2N 149.8E12.3N 142.5E13.5N 140.5E
AVERAGE 24 HOURAVERAGE 48 HOURAVERAGE 72 HOUR
--.-----------------------------
--------107-0078144-0048164-0084
189-0078201-0102299-0048046-0012
134-0030134-0054153-0024293-0114
284-0168300-0150308-0198345-0096
10.1N10.5N10.5N10.ON
10.7N10.9N15.ON14.6N
14.2N14.4N14.9N15. 8N
14.6N14.8N14.7N15. 3N
14.5N14.5N12.ON12.9N
ERROR - 0091 MI.ERROR - 0140 MI.ERROR - 0220 MI.
160.4E157.9E155.4E154.2E
151.5E149.7E149.4E150.2E
148.3E147.9E146.2E143.OE
142.4E144.2E142.7E142.4E
145.9E148.5E137.OE135.4E
---------------------------------
--------------------------------
---------134-0114168-0114169-0168
198-0162208-0192321-0072024-0054
270-0090295-0126311-0186305-0258
10. 8N
11.5N
11.6N
18.ON
15. 3N
16.2N
14.2N
14. 3N
14.4N
12.ON
156.OE
149.6E
146.4E
145.OE
144.7E
142.OE
137.7E
139.5E
144.2E
132.OE
.-------------------------------
----- ---------------------------
--.---.-------------------------
----------------194-0150--------
233-0252--------
326-0372--------
TYPHOON SUSAN - 04/18/05002 TO 04/25/05002
I. DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 292. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 123. DISTANCE TRAVELED DURING WARNING PERIOD - 882 MI
B. CHARACTERISTICS AS A TYPHOON1. iMINIMUM OBSERVED SLP - 943 MBS AT 21213022. MINIMUM OBSERVED 700 MB HEIGHT - 2615 M AT 22213023. MAXIMUM SURFACE WIND - 105 KTS (FROM BEST TRACK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 240 MI
II. DEVELOPMENT
A. INITIAL IMPETUS - 200 MB ANTICYCLONE OVER THE SURFACECYCLONE
B. INITIAL SURFACE VORTEX
1. EMBEDDED VORTEX AT 16050022. SURFACE PRESSURE LESS THAN 1007 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - SOUTHEAST2. UPON REACHING TYPHOON INTENSITY - SOUTH
III. FINAL DISPOSITION
A. DISSIPATED OVER LAND
5-7
.’.fpi
(2!..
4.
!w.
t
“W
1--i-kI“
I‘:]”
/’0+-
,y,,mf
.8;’T”””
.J--
.T.
..
..
.
.b
BE
.’-...=.,+
..
$,””&:”
:::;::%
...O
s”’”7””
Q,,,
~-.1—
5-8
LYE FI~E!jCYCMW; 03IJN1 [- I)(YS (MS Ml,
FIX1 L’i t dK!YS
PIETIIUU FL1 LvL SF c MIN (Uor.m 1 VL EYE. OR 1LN- LY’11No. TIME P051 I
.+Al_L-ACGY LVL WWJ $,IV{) SLP l-lb 1 rl/iu FUkv.1 (ATIUN IJIH LLuu(l
------- ------- ------- ---- ------- ------- ------- ------- ------- ------- -------- ---- ------- ------- ------- ------- ---”-.
it?343678910;;
1.314151617181921J212Z23242526~?282Y30313233343536
160508217U411Z1HU5107180530z18213UZ1902>5219041721907Z5Z1909U5Z192!1002200230Z2?00s122200740z2008452201400Z20204sZ21U230Z21061122114i)oZ2121.$c)z2202u5Z220518Z22092572212UOZ2214>022?221302230315223061322308.?72231530Z2321uOZ24021JOZ24052(-)Z240842Z2409U5Z2414uOZ
07.011 143.OEOb.ON 14300Eu9.ON 1+0.OEUb.4N 139.9EU7.lN ]3802EOb.9fJ 137*4E08.ON IY7.OE06.ON 13706E07.3N 1S608E07.3N Id4.9E07.4N 134.OEU7.5N 133.UE07.3N 133.lE07.5N 133.lE07.7N 13203E07.W 131.5E07.81’4 l~o.9E08.ON 130.5E08.ON 129.4E06.2N Id9.OE08.4iN Id8.8E08.SN 128QOE(J’+.ON 128.2EOY.2N II?8.2EU9.4N ]27.4EU90!5N ld7.oElU.lN Id6.2E10.oN 126.OE09.71w lZe.lE09.8N II?6.lE10.ON ld6.oE10oOIl 1Z5.9E10.ON 1C!5.!5E10.ON 12601ElU.ON 1Z6.OE09.9N IZ5.8E
SLTLS STG CSLTL5 STG CSLTL> srG d54-i’-LJ.<-llz 0350454-P-III-1(I 700MIJ54-P-111-05 0460WSLTLS SIG dVW-)+----15VW-P-U5-10 0320*i54-P-U5-04 700$!U54-P-U5-04 700MYSLTLS STG isvw-k ----15VW-P-U3-03 04504.$VM-R-US-11)54-P-U’3-03 700M1354-P-Z%-0”1 7oowhsLTLS STG XvvJ-R-d(l-(i~54-f’-U:i-o2 ?ooMt?54-P-I(J-01 70UM+SLTLS STG XVW-R-U+-05VW-R----O5VW-R-U5-U554-P-u.i-133 700W54-P-U5-O? 70UMtJsLTLS STG AVw-d-uj-oll/4-R-u5-ij5
;:-;-::-:: ~oo~d--- 5ooMliSLTLS SIG KVW-I+----}%
Vw-d-ub-o%Vd-ii-uj-(]q
UIAIJLFIIJIA
033USEIUJUUIA------048U41
I.)lA---U(2
--- ---,J55%“ 978-”
--- --- ---UC15 l)b5 !Jb3003 IItio 950uIA Uj 8N[\s 3--- --- ---
UY5 (l&5 943Ub5 lUO 943uIA US fitt)s 4---- --- ------ --- ------ --- ---
UY5 --- 944075 1)65 S&u
uiA U3 8NI~s 4- - - --- - ----- --- ---
(J,S --- ---
Uso --- ---UIA U3 I+%)s d--- --- ------ --- ------ --- ---
---3ut2---
------
21 /2511/102i /25
/-. --
2: /d41;/1214/12
/-. --~~ /~~
/-. --
lf/il21/lu
/-. --
2t/lr24/18
-./---./--
/--- -. --~b,5”(l*
11/12
y?< IF/lu,.
/--- -- --/--- -- --
---- ().2/55--- 09/’J1
/---- ---/-- - - . --
--- /----
--------
----------------
--------
----
------------
------------
--------
12’15
?315Idid
Ill(J9
UY
1<ud
Id
{J6C’c!2U
lU10
---.-.
--------
IJ!J----
----------
(J3--
--
--
--1*.t.lj.IJ.Fou.
WARNNO.
08
09101112
13141516
::1920
21222324
25262728
lYTG
192300Z
20050022011OOZ20170022023002
2105OOZ2111OOZ21170022123002
22050022211OOZ22170022223002
230500Z2311OOZ23170022323002
240500Z2411OOZ241700z242300Z
WARNING POSITLAT LONG——
07.4N 134.6E
07.5N 133.6E07.6N 132.8E07.8N 131.9E07.9N 131.2E
07.9N 130.4E08.lN 129.8E08.ON 129.OE08.3N 128.8E
08.4N 128.6E09.lN 128.lE09.5N 127.2E09.5N 126.8E
10.2N 126.lE09.9N 126.OE09.9N 126.OE10.ON 126.OE
10.ON 125.8E10.ON 126.OE09.9N 125.7E09.8N 125.5E
TYPHOON SUSAN
TROPICAL CYCLONE 03 -- 04\18i0500z TO 04\25\0500zPOSITION AND FORECAST VERIFICATION DATA
07.4N 134.7E
07.5N 133.8E07.5N 133.OE07.6N 132.2E07.7N 131.4E
07.8N 130.6E08.ON 129.9E08.2N 129.4E08.4N 128.9E
08.7N 128.5E09.ON 128.OE09.3N 127.5E09.5N 126.9E
09.6N 126.5E09.8N 126.2E09.8N 126.lE09.9N 126.OE
09.9N 126.OE09.9N 126.OE09.9N 126.OE09.9N 126.OE
24 HR FCSTLAT LONG— —
08.3N 131.6E
08.4N 130.3E08.6N 129.3E08.9N 128.6E08.8N 128.3E
08.8N 127.8E09.ON 127.lE08.6N 126.3E09.ON 126.5E
08.7N 127.8E10.3N 126.OE09.5N 124.2E09.6N 124.4E
12.2N 124.4E10.6N 125.OE10.5N 125.lE10.8N 125.3E
10.ON 126.OE09.7N 124.8E
AVERAGE 24 HOURAVERAGE 48 HOURAVERAGE 72 HOUR
HR ERRORDEG DIST
030-0048
060-0030055-0048064-0066019-0036
341-0036320-0042314-0054308-0036
279-0036270-0048238-0078211-0030
114-0126348-0030261-0108259-0090
326-0162307-0066306-0060326-0060
09.4N 128.6E
09.2N 127.lE10.ON 126.7E10.3N 126.2E10.4N 126.lE
ERROR - 0061ERROR - 0110ERIW3R - 0184
09.5N 125.6E09.7N 124.9E09.ON 123.7E09.3N 124.6E
08.9N 125.6E10.8N 123.7E08.7N 121.3E08.8N 122.2E
14.3N 123.6E12.ON 124.OE11.8N 124.lE
MI.m .MI.
48 HR ERRORDEG DIST
--------
------------------------------ --
---------------------- --348-0060
291-0078309-0090309-0090322-0066
263-0048266-0072251-0144246-0084
197-0060292-0138256-0282254-0228
72 HR FCSTLAT LONG——
10.3N 124.OE
11.8N 124.4E
09.5N 123.6E
08.5N 121.0!3
08.9N 123.6E
08.2N 118.3E
17.3N 124.3E
13.2N 123.4E
72 HR ERRORDEG DIST
--------
.----------------------------.--
---------------------------- -----
----------..---------------------
286-0150--------
321-0150--------
261-0138--------
255-0300--------
TYPHOON TESS - 07/OS/1100Z TO 07/11/1100Z
I. Dti.A
A. STATISTICS1. IsJUMBEI?OF WARNINGS ISSUED - 132. NU?.lBIZP.OF WARNINGS WITH TYPHOON INTENSITY - 033. DISTANCE TRAVELED DURING WARVING PERIOD - 906
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 974 l~s AT 100S40Z2. 1.IINIIIU14OBSERVED 700 NIB HEIGHT - 2859 M AT 10021523. MAXIMUM SURFACE WIND - 070 KTS (FROM BEST TRACK)4. MAXIMUM RADIUS OF SIJp~ACE CIRCULATION - 300 ~,11
II. DEVELOPYIENT
A. INITIAL IMPETUS - DEVELOPMENT OF DIVERGENCE AT 200 !4BOVER SURFACE CYCLONIC CIRCULATION
B. INITIAL SURFACE VORTEX1. JUNCTION VORTEX AT 050000Z2. SURI’ACE PRESSURE LESS THAN 1009 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - NORTHEAST2. UPON REACHING TYPHOON INTENSITY - EAST
III. FINAL DISPOSITION
A. DISSIPATED OVER LAND
5-11
,.
~tiO3NO1OAO
/
-{6961lflfII-M)IOIJJ
SS31NOOHdA.J. 0
)lWtil1s38
050439Z06063&+z080s4020904U070904452090638209090520913U5Zl)914uoz09212021O”OOU(JZ10U2’15Z100737Z1007*5Zloof340i!1012UOZ1014UOZ1015UOZ1017Z5Z10211OL11OOUOZ11OZ*5Z110254Z111010%1110302
U8.01~ .135.OE0800N 128.OE11.01* 1Z2.OE13.2N lltI.8E13.2N Ilt3.7E13.ON 118.5E13.41N 117.8E13.81U 11608E14.OIN 1115.5E14.31~ 114.4E14.5N 11308E14.bN 113.3E14.ON 111.5E14.9N 1A2.lE14.9N 11202E15.2(% 111.3E15.6N 111.lE15.l+N 111.13Elb.ON 11O.5Elb.OIY I0908Elb.5d IU9.lE16.tJN IU8.6E17.0(4 1U1300E17.(JN IU704E16.9N 107.2E
SLTLSSLTLSSLTL554-P----10I/w-f+----lo
SLTLSVW-P----10VW-R----1I)VW-P----O554-R---- o54-P --..-(j~
54-P----05SLTLSVW-R----2(JVW-P ----10vw-~----lovw-p----lJ)
vw-R ------Vw-p----lo54p ----1554-P----O5‘54-P----05SLTL5VW-F?----U5VW-R ----02
STG BSTG BSTG X50UMtj7oot.ltj
STG X223011
700MH700M(4700M13700MH
STG X
02904
700MH
700MH7ookllj70(JMij700Mi-j
STG X
I)lAL)lAUIA035---
I)LA---------0354)52(.)t15lJiA---------llta5------IJbs
()/0obsI.)lA------
-- BNrIS -‘- 13NoS -U2 BNgs k’
945 991 ------ --- ---
U2 BNi)S 2(165 ,9tio ------ --- ------ ---<--$lb 295u--- ‘..,3069!)70 9~9 :2874070 --- 2tJ59
U+ BNI)S I?--- ---
070 9j4 :::--- --- ------ 914 29H4--- . . .---
964 ---2962
--- 987 2’484000 9U9 29901]60 9t19 3011
u~ 8NIIS ~--- ---(J25 9’j6 ~1~
01/55- ,/--
/--4 --
xii/-----19/1420/09
/-- --
29/25
;:;;;
;;;;;16/1220/1516(12
/-- ----/--
CIHCLJIW
--------
tLfPCIUCCIUCCJHL
---------------------
CIRC----
CINCLJtiC
--------
--------
I*W->L
----
----
----
----
----
----
40
lblU
----
1-----.---
Iu
-------------.----
----
TYPHOON VIOLA - 07/’2l/23OOZ TO 07/28/0500Z
I. DATA
A. STATISTICS1. NUMBER OF t’7ARNINGSISSUED - 262. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 183. DISTAYJCE TRAVELED DURING WARNING PERIOD - 1854 ?11
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 897 MES AT 2G21OOZ
2. ~.:lN1}luMOBSERVED 700 ~,~BHEIGHT _ 2137 ~4AT 262100Z
3. MAXIMUM SURFACE WIND - 130 KTS (FROM BEST TRACK)4. J’JVAXIMUMRADIUS OF SUP5?ACE CIRCULATION - 420 MI
II. DEVELOPMENT
A. INITIAL I.MPETUS - 200 MB ANTICYCLONE OVER THE SURFACECYCLONE
B. INITIAL SURFACE VORTEX1. JUNCTION VORTEX AT 180000Z2. SURFACE PRESSURE LESS THAN 1008 MBS
c. 200 MB FLOW A130VE SURFACE VORTEX1. INITIAL - EAST2. UPON REACHING TYPHOON INTENSITY - SOUTHEAST
III. FINAL DISPOSITION
A. DISSIPATED OVER LAND
5-15
-1 ,- ,P~ i+,
‘L4
. ..6T ... ,..
.,. ,,, ,
*
0
30+ —H
,..
.
14(T
.J
;m$i~w:
+ &--t--- – +1--+-+1,sNo J!MA
,.’,
‘W”=hn
-1...
+10”+ 0 –t’-+
L. ’I.L. . ..O.
BEST TRACKTYPHOON VIOLA
21-28 JUL 1969 -CYCLONE 05
LEGEND +–H 6 HR BEST TRACK POSITS
* ** M’FEEN&— ~T~~t4 OR TKOPICAL
‘---TROPICAL DEPRESSIONcm FORMATIVE sTAr3E
+—-%15
%., 16< A
.\b.
. ..” “K 1.,,, .T .,..
t+.. . ..L
+x
t
*Y; ““ ‘A?s’i..u“‘ “’L+.+$ii3 II.13, , .’40.!3,0 “M
23Z. ..,,.,.,..
‘1” ~
. . ..
L
“l’ %)....-,.- -.. ..
/%x ‘,EN,wi,m-
1,.- .12,’’”””’”” ‘2m’Ar0L-...
-t -ttW ,..+- t-ilo,l-+- -+-t-+o +10++-’
,.. y#~w 1.. ,., .,. ,,, ,,-
4bK“”
+
.--.--------------.---Q(.--
--
--
--
--
+{,--
--
Q(Ic1
c1--p,)
01
----1)(1
--
~[1
::
F{If1)nr--
.-
.-------
----
----
----
----
----
------------
----------------
--------
=lq-MN--------
..---------------
qq-mrd
7C-MN
/ ----/ ----/ ----/ -.--/ -.--/ ----/ ----/ ----/ ----/ ----
--/--
=!:: / ----/ .---
Q1/l?/ ----
9T/z?/ ----/ ----/ ----/ ----
?r/!??FT/9?
/ ----/ ----
+1/81+T/6T
/ ----/ ----/ ----
?T/9[nl/qI
Tr/9T9?/9z
7.1/’=T?1/s1+7/9?G?/G?
/ ----
+7/+.?+?/s?
-------------------------------------------------------------------------------------
---------------------------------~btl------
---o)ntwnol---
---
---
---
Len
---
---
---
---
Ccn------,
bS(NUcl-lVl(lyfllsSills30*l171NO*T?------------1(7?106$)1“1onT------------
LCT~Jb\168---OTT---~,,-------------------------------fl}n------I)&l!---
+JsUN14QOVT(ILF77/@En6q7THTT+{1,77bor1657r001---%~’-,-----eon------qp[$non
tlsLNfl+:()Vl(l
/.(tz’@c76!-JillconO+*?ORI)---d,w::!---::!------------------c,~l,---
*S(fFlfl?IlvTflR<Q?.\@ZG6Tjnl06.0
1LP7‘LILFiG!nq~n
F36?1b0$26---------b.9fffj0+0---
-S(hla--Vlrrbhr%?266S*O0+0F667266---s7n----166()*()-------+766f)+i~So(l------------
-Sdhlw--VT(-I---6L~()+(,()+lfl---000Srci)*ll
-5(’NQ‘-VT(l
3c”07f76”07[70”17[3+”,?7137”2?1Zr?”i??[3$)*F713R”+77[30”$?136”s7’13L”97132”/713E”87130”07[3E”6?IIll“OI?I3B”1FI3z”i?rI36”ZF1qo**fl30”Grl3**9fi3fl”LFl79”8F(30”8rI3*”6FI3?$0+130”1+[3H*1+13s”$+s1311”47*[3?J”f*l3S”E+I30”P+I
-----------------------------------------------------------------------------------------------------------------..-.{11>,,1-)w1nhlr?~iylUei)d0]/111~MC-I-IS(]F.IQ(1h,MlA1.I.l!jk.7)7
A33v-1~c(-1~
-tiaIPn3A2TATPwllfll
7*I1“(V4
NIW3-!\>AJ<1\lLlI
114111-w13w114.’~wSa(-1
xl+SRI:11+
go~,lf),,~oSqy,j2A;’“’”
.
TYPHOON VIOLA
‘1’ROPICALCYCLONE 05 -- 07/21/23002 TO 07/28/05002POSITION AND FORECAST VERIFICATION DATA
BEST TRACKLAT LONG——
09.3N 141.5E09.8N 140.7E10.6N 140.OE
11.6N 139.2E12.6N 138,2E13.7N 137.2E14.8N 135.9E
15.4N 134.4E15.7N 132.9E16.2N 131.5E16.4N 130.3E
16.7N 128.9E16.9N 127.8E17.lN 126.9E17.6N 126.3E
18.3N 125.5E19.lN 124.4E19.5N 123.2E19.8N 121.8E
20.4N 120.6E21.lN 119.6E21.7N 118.4E22.4N 117.4E
23.3N 116.6E
24 tiRFCST 24 HR ERROR 48 HR FCST 48 HR ERROR~T LONG DEG DIST LAT LONG— — DEG DIST——
72 HR ERRORDEG DIST
WARNNO.
030405
06070809
10111213
14151617
18192021
22232425
26
WARNING POSITLA’S LONG— —
09.ON 141.3E09.7N 140.5E10.4N 139.9E
11.3N 139.OE12.7N 138.3E13.6N 137.4E14.9N 135.9E
15.7N 134.7E16.3N 132.5E16.4N 131.3E16.4N 130.2E
16.8N 128.8E17.lN 127.8E17.3N 126.6E17.3N 126.4E
18.ON 125.5E19.2N 124.lE19.9N 123.OE20.lN 122.OE
20.4N 120.4E21.ON 119.4E21.7N 118.5E22.2N 117.4E
23.3N 116.3E
72 liRFCSTLAT LONG— —DTG
2211OOZ22170022223002
23050022311OOZ23170022323002
24050022411OOZ24170022423002
25050022511OOZ25170022523002
26050022611OOZ26170022623002
27050022711OOZ27170022723002
2805002
10.6N11.9N12.5N
136.9E136.4E136.4)2
12.ON13.5N14.7N
133.OE132.8E132.9E
------ ----------226-0066
176-0114211-0138202-0114170-0138
147-0108069-0144070-0150033-0132
014-0126307-0132310-0102275-0060
264-0108239-0090234-0090138-0132
117-0114314-0024333-0012180-0012
249-0078
----------------- - ------
--—_____------------------------
--------178-0222156-0174124-0180
098-0162054-0252047-0246002-0174
329-0162272-0258269-0192242-0102
251-0126242-0132238-0120143-0258
134-0144
..15.lN 129.lE
18.5N 128.OE
21.5N 125.5E
22.ON 118.lE
21.ON 115.OE
22.5H 113.7E
24.ON 112.OI?
23.3N 115.6E
-------------- -------- - .
--------------------------------
---------------—--- - -- ----------
----------------133-0174--------
086-0138------- -047-o174--------
304-0168--——----
258-0186--------
253-0162
13.8N16.6N17.lN18.3!i
135.5E135.3E134.lE131.6E
131.8E131.4E130.lE126.4E
16.3N19.4N19.9N20.5N
18.8N18.3N18.2N17.7N
129.5E125.9E125.5E125.2E
20.7?419.3N19.4N19.ON
124.OE119.81z119.8E120.21?#
18.lN18.3N18.6N18.lN
123.6E123.OE121.9E123.4E
118.4E117.4E116.5E120.2E
19.7N20.ON20.6iJ18.9N
co1+
A
122.4E119.2E118.2E117.3E
118.5E114.5E114.5E
19.5N21.4N21.9N22.2N
21.ON24.7?424.7N
MI.MI.MI.
22.8N22.8N23.8N
115.lE114.lE114.OE
AVERAGE 24 HOUR ERROR - 0099AVERAGE 48 HOUR ERROR - 0181AVERAGE 72 HOUR ERROR - 0167
TYPHOON BETTY - 08/05/0500Z TO 08/08/11.00Z
1. DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 142. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 043. DISTANCE TRAVELED DURING V?ARNING PERIOD - 1242 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 962 MBs AT 08020022. MINIMUM OBSERVED 700 MB HEIGHT - 2796M AT C)7211OZ
3. MAXIMUM SURFACIS WIND - 070 KTS (FR0M BEsT TRAcK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 360 MI
II. DEVELOPMENT
A. INITIAL IMPETUS - UNSTABLE EASTERLY WAVE UNDER 200 MBDIVERGENCE
B. INITIAL SURFACE VORTEX1. JUNCTION VORTEX AT 021800Z”2. SURI’ACE PRESSURE LESS THAN 1008 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - NORTHEAST2. UPON REACHING TYPHOON INTENSITY - EAST
III. FINAL DISPOSITION
A. DISSIPATED OVER LAND
5-19
WII-do
L::i:::h:::t.:.:b147 AS
I
i+--+-i+
.. .. .. .. .--..
G
K –’101* +- -,,,
. . . . .0,
.- -.. . BEST iRACK,.. .
TYPHOON BETTY :.
+’+
t
1
t ‘4-T :x. M..”.\ ../*do.
05-08 AUG 1969 +CYCLONE 08 .
LEGEND
“r
-4P4 6 HR BEST TRACK FOSITS
~ ‘~ %??EEN21TY— TYPH~N OR TROPICAL
----?~~I~AL DEPRESSION t020 ~RMATiVE STAGE
_* :....- ,L: ~-+; ,.I
*.X ““”””””””””””””””../*’” ““ ‘.
/
: ~~ ~,,/+/ 1‘W!tiibl&uNtlA2W~
&L-+-- .+*-.,-. .+ ..+.. 6A .... ... +..,.+ _+-,. . .- .. . . . .- -...,
‘~! 1- -’”’-
di~”!iii : ~ ; -w ! :!: A/a :2:::: + :-: ~ ~ +?!+:i. . . KwAJAm,.Qmix t
..-+–-l—k -- l-------1- -+”+-+
. .
u-lI
041J23UZ050(JztizlJ505bbzo~f?iz~zU6U2152
060517Z06iJbUOZ06u9d(17ub14+5z[)621U(JZu7u2ubZU70SUUZU706U(J.Z07iJblbZ07U63UZI)7(J?UOZ.07ut$lluzU71J9UOZ07L1900ZO’7U9U(JZU709LIUZ0711007U712U07.0713UUZu714(l(j~0714U(JZ07141010715u(J~0716UOZ072UUUZ072110Z07Z2U(JZU723UOZOHUZIJOz
dt+UZUIJlUH02UUZ0H023UZ0P0231JZlJHL)4SIJz
0H05U07(JH06U01oHoluuzUI+OHUUZ0HL193UZOHIU(J(JZ
u9.9PJ I*202E13.4N 138.6E14.21’4137.9Ei?.lN 134*8E11.’3N 133.7E18.UN 132.5EltI.9N 131.lE19.fdv 131.lEZU.3N 13u.2E
54-P ----3054-P ----2014W-P----(J554-P----1554-p----2~
SLTLSVW-R----Z()VW-P----20‘JW-P----10
046(JML1460M03UON700MM700MU
STG C
0240.,?Oom
54-P----,,3 ‘700Mti54-P ‘---03 700MtJLN(J Nbl?LND Nl)ftSLTLS S16 XLNIJ NL)RLND HI)RLND NOR
LNIJ RL!RLND i+bRLNO lil;~vw-p----()~ (J230.ILND ii[)RLND hl)RLM) KI)R
LNI) HIJRLND NI.JRVd-1-l----loLNl) KIJRLN[) UI)HLNO dI)R54-P----U? 500MiiLNI) HIIRLNIJ tiIIRLW ~(,1~
LNL) itll~54-p----,,~ SOUMt~LNL) HI!RLhjl) Iil!k
LND HIRLND I<IIRL hjo HIIRLND ltI)RLN1) HIIRLN1) k,J~
LNII tt(l~
030 {)15 (JU5(J35 025 “001--- ()!J5 9931)>5 --- 9d7U45 IJ4(J 989UIA ‘- tlNqs ---- --- -=-
U41J U45 965055 --- ---045
ub(j----
---
uIA-“-----------------uf!li---------------------------Odo------------
u/(J----------------------------
IJbo 9800 ro 975--- ------ ---
0,? fjpl!]s3----+-------------Ufo--------------------------------------------------------------------------
-----------------, -973---------------------------
905------------
90,?!---------------------------
---------
29952’+87
---------
2951Z897------
-------------------------------------------------
2/96-------------------------------------------
24* 2426) 2427)2514/1014/11
-- /--
2542313/u915/1.116112
t-- ----/--
-- /--
t-- ----/----/--
/-- ----/..-~5/25
4-. --/-- --/-- --/-- --4-- --4-- --
-..,---- --4--, --
02/ 52-- /--
I-- --/-- --
/-- --
(J2‘5bt-- --f-- --
-..t---- t---- t---..t-..-..4--
t-- ----t--
CIHC----
Chic--------
----CIHCCIRCCIRGLt+tc--------
------------------------
UIRC---------------------
Clitc------------Clue----------------
CIHC------------------------------------
----
----
----------------
----
----
----
----
33
L)5
2(Jdu14If?
lz
15
lb
1>
------
F*II.F.ria
----
--
(I3t.)j----
----
--
------
,) 6--------------.---1)5--------
t,>---------.-------..
-------- .. -----
WARNNo.
010203
WI 04INw
05060708
09101112
1314
DTG
0505002O511OOZ051700Z0523002
060500ZO611OOZ06170020623002
0705002O711OOZ0717002072300z
0805002O811OOZ
‘1’ Yl?HUUN BE’T’LX
TROPICi& CYCLONE 08 -- 08/05/05002 TO 08/08/11002POSITION KND FORXCAST VERIFICATION DATA
NARNING POSIT BEST TRACK 24 HR FCST 24 HR ERROR 48 HR FCST 48 HR ERROR 72 liRFCST 72 liRERRORLAT LONG LAT LONG LAT LONG DEG DIST LAT LONG DEG DIST— — — — . — L?.T LONG DEG DIST— — — —
14.ON 138.OE15.ON 137.2E16.ON 136.5E17.3X 134.5E
18.6N 133.OE20.ON 130.7E20.6N 129.8E21.5N 128.lE
22.6N 126.5E23.6N 125.OE24.6:4 123.6E24.8N 122.4E
25.7N 121.7E26.3N 120.lE
14.ON 138.lE15.2N 137.OE16.4N 135.8E17.4N 134.5E
18.4N 133.OE19.6N 131.2E20.6N 129.6E21.6N 128.OE
22.6N 126.5E23.5N 125.lE24.2N 123.6E24.8N 122.6E
25.7N 121.6E26.3N 120.3E
17.8N 134.9E -------- 20.5N18.7N 134.OE -------- 21.4N19.4N 133.OE -------- 22.3N20.9N 130.lE -------- 24.ON
22.8N 128.4E 108-0108 26.9N24.2i4 125.6E 109-0162 28.4N24.2N 125.4E 110-0204 27.7N25.9N 122.5E 110-0120 30.lN
26.7N 120.8E 084-0102 -27.7N 119.4E 030-0048 -28.4N 118.6E 090-0096 -26.6N 117.lE 360-0066 -
28.2N 117.9E 325-0072 -28.4N 115.9E 330-0096 -
AVERAGE 24 HOUR ERROR - 0107 MI.AVERAGE 48 liOURERROR - 0243 MI.AVERAGE 72 liOURERROR - 0330 MI.
131.4E129.8E129.OE126.2E
125.6i?122.2E121.7E118.OE
------------ ---------- - ---------
--.-.---------------------------
115-0294116-0282111-0312104-0192
072-0222038-0156
23.ON 126.9E
25.ON 125.OE
31.9N 125.8E
--_--——_---------- --------—-----
- - - --------—--------------------
------------------- --- - --- - . . - .-
119-0330--------
TYPHOON CORA - 08/14/23002 TO 08/23/0500Z
I. DATA
A. STATISTICS1. NU,MBER OF WARNINGS ISSUED - 342. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 153. DIATANCE TRAVELED DURING WARNING PERIOD - 2226 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 948 MM AT 19Z1OOZ
2. MINIMUM OBSERVED 700 MB HEIGHT - 2652M AT 20023023. MAXIMUM SURFACE WIND - 085 KTs (FROM BEST TRACK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 330 MI
II. DEVELOPMENT
A. INITIAL IMPETUS - 200 MB ANTIcycLONE OvER THE suRpAcECYCLONE
B. INITIAL SURFACE VORTEX1. JUNCTION VORTEX m 120600z2. SURFACE PRESSURE LESS THAN 1007 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - SOUTHEAST2. UPON PJIACHING TYPHOON INTENSITY - SOTJTHEAST
III. FINAL DISPOSITION
A. BECAME EXTRATROPICAL
5-23
[111,3, -L-. 1. Q. .. -l. 7,4 .-l. .’---
163
5.%6
w i!–t. 4– -+
q;-, ‘g :“:$14W .
;~h.iv
Lui!mQ
I
.,.. .
e &i ~_ll?BEST TRACK FOSITS +1–-t--+--- ,+-i-4.. -- ....
.’$,.Wu.
+-t+
+ *“* WARTY +
LWcd’mi I I
t
“::[.,
-.+201 –+ --++–-+
o WAKE~,~,
,.
,,, ,,
“1,..--t-t-++-+-l
.,.
~ ii4wi1w” :2W,W ,
I—or+- +— t—-t=
-,84KWAJA,E,N&,,. ,,
. ,.. .-., .-,, ., ,. .,. ,,. ,.i I ! A W? “f 1-+-I--&K”;::--l---t– I.,, : 14/2sz . -. . . .-. ..- -. ..- . . . . . . .. . .+ . ...4-.... -L . . . .4- . . . .&. . . .& . . . L.. .
I I
,
,?..1
___
-..
1
.J-
1.11
1:;-11
..
AL
Iulll>
1-111-
lT>l*ln
-)>1
IVII
I,O,
,,,,
1:-,:,z
--11-1111:1
Iltk
111IllIllIll
8IllIll
1111
1Ill
IllI
1Ill
tt
tllIll
::
IllI
III
1’
:/
I:
-JJIIJ
III,.J,
Zxllxllllrl
--11-1111-I
2.JIIJII,,.J,
I-11-lw
+Iw
l-l+d\\\\\\I,n
loo
=I-u
l-l-l-u
*1>151”5..X
ll-lola
Iill+ll
l,,,1111+111,1,
\\\\\\\*lm
lf-lr-\\\\\\\\\\\
‘NI--l-l-l
111i*lllt81Illlw
lll,,,
1114II1!UIll=
II
11
11
QI
11
11
8lltl+l
l&,,,
1111:111111-+,-<
.LJk
5’
.
5-25
W
FIXNo . TINL
LYf_ FIXES CY7LUNE
lJNll-09
fLT .,)t)s ObS Mll! FLTi.lETttOU F“LT LvL 5Fc t41N
lml\l\
700Mt) LVL llYk u,<l LN - tlL +/,1.1PUS I I -ACL.Y LVL WI*[) ,4Iqo SLP nb r iT/ltJ FOI.,4 “Il+)lult l)i(\LLO1li,
------- ------ ------ ------- ------- ------- --.---- ------- ------- -- ------------------- --------- -------------- -------- -,51Sd5354555051E.ti5’+6061(x’63646>(lt]b(tiu697(I71727374-757b7r7b79Hu81l+<R384H>Ho8/80H99(1919d939*95$lb9(9899IrJu
20UH55Z2009.?02201010/zo1415z2014J6Z.?o161oz2021OIJZ21OZ15Z21O’23[)Z.?1U3U(JZZ1U4UOZ.zlu44(Ji!2105ZOZ2106uOZ2109UOZZ1093IJZ2111U(JZ211*25.?2120UUZ‘21211u(lzC’lr?idozZIzluoz21Z2U1)Z2122uozz123doz22UOOOZ2!?00202<?~lu(lz
270200222u31JOZZZIJ4UOZZZ05UUZ2?05392Z.207UOZZ2U5UOZ2Z!U9UUZ
22rJ9ulJ7Zzlluul2212UOZ22121OZc’214iJo72214uOLZ215UUZZ?leuoz
2217uuZZ21HUULZ219UI)Z/2’2uu(J/22Z1UU{2221152.
d?.fm 127.2E.?T.bld 127.4fz7.&14 1Z7*1EZ8.lN 1Z7.HE2d.oN 1<7.4Edb.2N ld7.7Edb.til~lc!7.bE?b.~,f IZ7.UEZ9.2N 1c8.OE2/.UlM IZ7.IE27.(IN IL’7,2Er?9.bIt Idtl.OE2{.214
27*2N29.WJSU.2N3U.2iY3U.7N31.2NJ1.lN31.M31.3N31.314.31.4N31.31431.51431.ZI*31.5N~i.bN31.71*31.W.Id.olu32.ON3.?.4N32.614
]<7.OLIL’6.9E]dkl.2EI<B.OEI<B.4EJZ8.6E129.lEIZ9.2EId9.2EIZ9.3E1.?9.4E]29.6E129*6E1c!9.HE130.2E130.3ElJo*bE]30*9E
LNi) u,l~
VW-R----U4v~-p-..--()~ 700MtfVW-R----OSLND rtUKLNII MbR54-p ------ 7UOM*,LrJ[) N!JR54-p----(J3 7oo*-~ND HIJRLNO til)~
sLTLs Srtix
--- --- ------ --- ------ (Jijl-1------ --- ------ --- ------ --- ---lJi~ --- 958--- --- ---
(JOU (J85 9bl--- --- ------ --- ---i)l/4h.+ UN[)S3
LNl) }([)14LNI) N,,Rv~-~ ----1%vt+-R----l(lVW-P----(J5VW-R----11)LNIJ I~!)RL N() iil!l.(54-P----(J5
LN[) H1)RLN[) t(l,~LND Iil nLNr) !{lIRLNl) tiuR54-P----IJ5
L$il) HIIRLhJ~ I+llu
LN1) kli R
------------
7UOM!’I IJ(b---------
50 UM?! UtJ6---
‘. ---
---
---
---
51J(JW (JU6---
---
---
------------{155---------------------------------------------
---------,---9bU---------
903---------------Yblj--------------.,
31.3E LNLI HIJR ---
31,4E LN13 NIIR ---
31*SE SLTL> Sfti x IJIA 03 BNIS d
32.uE L II 1) <III? ---
32,4E LNI) HIJR ---
LNI) I,(,?Hv~-u----{,.{LNIJ ?tIIRLNO Mlitiv#/-l<----il)VW-H----1~2LN[) d,lnL!du I’(IIHLNIJ -lI$uLNU -(Ill’?LNI) .4,)RL ND 4ti~
L“il) NII*L N1) *{,;R54-P----1IJ
-------------------------------------------
Soovti 000”
--- ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ------ ---
------
/731---------
dr25---
2771------
------------
2748---------
2?(.1---------------------------------
---
--------------------------------------------------
/----/..---
2’1/13--/..---/--
/-- --
16/lU/-- --
17/u9/-- --
--/--
/-- --
/-- --
/-- --
;;.-;;
/-- --
/-- .-
/-- --
u4/uo--/--
/-- --
/-- ---./----/--
u4/uo--/----/-..
/-- --
/-- ----/--
/-- --
/-- --
/-- --
/-- --
/-- --
/-- --
/-- --
/-- --
/-- --
/-- --
/----
/-.. --
/----
/-- --
/----
/----
35/50
------------CIRLC(WLC(KC
CTQC----
----
----
----
------------LI+LCIF?Ctl.lt’--------
L[!il.---------------------
Clf?u--------------------
--------------------------------------------------------------------
----------------
--------NL->11
----
----
--t.,..
--,19
11>
.!0
,).2--1;3_.--
--
--
--
--
113..---------.-----.-.-.--.-.-.--
----.-1:5--.---
t.<.----------------
4.P.(>.
4 $
TYPHOON DORIS - 08/31/0500Z TO 09/02/0500Z
1. DATA
A. STATISTICS
1. NUMBER OF WARNINGS ISSUED - 092. NUMBER OF WARNINGS WITH TYPHOON 1NTENSIT% - 033. DISTANCE TRAVELED DURING WARNING PERIOD - 612 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 973 MBS AT olo250z2. MINIMUM OBSERVED 700 MB HEIGHT - 2865 M lfl’ 91025(Iz3. MAXIMUM SURFACE WIND - 065 KTS (FROM BEST TRACK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 240 Mx
II. DEVELOPMENT
A. INITIAL IMPETUS - DEVELOPMENT OF DIVERGENCE AT 200 MBOVER SURFACE CYCLONIC CIRCULATION
B. INITIAL SURFACE VORTEX1. INDUCED VORTEX AT 300600z2. SURFACE PRESSURE LESS THAN 1006 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - NORTHEAST2. UPON REACHING TYPHOON INTENSITY - NORTHEAST
III. FINAL DISPOSITION
A. DISSIPATED OVER LAND
5-29
+..
.~
....-...+
....+2
%i%
=k-i$‘‘“+.
.““”t”’””t””””t”’y
.+
..
..
+...+
....
,.*
“+”
”.’+””–””+C’U3”””
X,.,,
~’.
..
..
.~1’””’-
.i..
,,.;
+..‘%
.”..
g,,
.~.,..
-...
.,,.
b.,
5-30
TY9HOON Ex3RIS
TIK)PICAL CYCfJ3NE 10 -- 08/31/05002 TO 09/02/0500zPOSITION AND FORECAST VERIFICATION DATA
BEST TRACKLAT LONG——
24 HR FCST 24 HR ERRCIB.
~ “E””’”
48 HR FC$Tf@NG
WARNNO.
01
WARNING POSITW1’G ~ LON——
48 I’IRERROR 72 HR FCSTEG I)IST LA? LONG——
72 HR ERRORDEG DIST
3105OOZ3111OOZ311700Z3123002
14. 6N15.ON15.9N16.4N
116.6E115.6E114.OE113.lE
14.6N 116.6E15.3N 115.5E15.9N 114.3E16.4N 113.lE
16.5N 111.6E16.7N 11O.3E17.ON 109.OE17.ON 107.7E
17.lN 106.7E
16.2N16.5N17.8N18.714
112.OE11O.9E109.7E108.7E
--------------------------------
17.7N 1.07.41?lfl.2N 106.3E19.3N 106.5E21.ON 104.2E
----.---------------------------
------- --—----------------------
---------- - -- -------------------
--------
04
05060708
O1O5OOZ011100201170020123002
111.5E11O.3E108.9E107.6E
16.8N16.8N17.ON17.2N
18.6N17.4N
106.4E105.8E
134-0024111-0030037-0060028-0114
Im .MI.MI.
------------------------------ --
09 0205002 17.ON 106.6E 352-0090 046-0048 -
AVERAGE 24 KOUR ERROR - 0063AVERAGS 48 HOUR ERROR - 0048AVBRAGE 72 HOUR ERROR - ----
, ,
TYPHOON ELSIE - 09/19/05002 TO 09/27/11002
I. DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 342. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 263. DISTANCE TRAVELED DURING WARNING PERIOD - 2760 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 890 M5S AT 24030022. MINIMUM OBSERVED 700 MB HEIGHT - 2140 M AT 240300Z3. MAXIMUM SURFACE WIND - 150 KTS (FROM BEST TRACK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 600 MI
11. DEVELOPMENT
A. INITIAL IMPETUS - DEVELOPMENT OF DIVERGENCE AT 200 MBOVER SURFACE CYCLONIC CIRCULATION
B. INITIAL SURFACE V’0W2EX1. EMBEDDED VORTEX AT 17000022. SURFACE PRESSURE LESS THAN 1006 MBS
c. 200 MB FLOW ABOVE SURFACE VOF3X!X1. INITIAL - VARIABLE2. UPON REACHING TYPHOON INTENSITY - EAST
XII . FINAL DISPOSITION
A. DISSIPATED OVER LAND
5-33
U’1I
wI
u(n
LYE FIXES C((L;;; 14
lJhll I - I)us rJti S Mi!l
FIX METHWJF(-I I HK14S
FLT LvL >k c MIN “(OOMIJ LV1 kYL
----!::-----:!:!--------::::!------:::::-------:::-_--::!---:::---:::---:::--
OKrLli- LYL .’IALLir/lo k“u ,214 lArlul* U14 LLUUi)
----- . ----- --- -- - -- --- - - ----- - ---- - . - ---
1234
5
6789101112131415.161718192021222324?52b2728?Y30313Z333435:]b.37383940414243444346414d
170211218031(1218U445Z190’35821904U9Z1920+5z200230220031/220092822(Ji43Yiz20213022102452210411Z2109d~z2114UUZ21210022203UOZ220314Z22063022ZU9U3Z2211-+.?22214boZ2221UOZ230015223024S2‘2304132z30t31Juz23utJ+ot23i2il)zC’31442.?232113724(J300f2405ilZ24U9LUZZ4L2UIZ,?4141)5124.213gz25UUU072s021s2
2sobluzd5uti41)7251193(lL25104572!s113112251141Z251435%?52U*5Z?5?34114
ib.ON16.UIf17.214i7.8NII*ON17.3N1/.511lb.514lf-).wlb.rdlb.6N16.4!1lb.Sdlb.31’4lb.51$16.414Ib.td16,5N16.dN16.91*16.9Nlb.9NAt).lldlM.01%1H*2N18.014113.6N16.4NiH.Ml*19.11’4lY.7Ni?u.i?l’4C’l*ON21.OIV21.4!4r?l.5N.?<.lf~2.2.2.4r?d.5NC?3.01*22.51V2/.41’4
2Z,V14
Z3.lN.2.2.9Nr?i!.91923.4’423.314
lb6.OElb5.5Elb4.2E104.4Elb3.UEItJ3.4E]8107E]02.OE101.2E12907E1$7.9E]56.8E1>6.55]34.5E1>3.9E132*3E]30*6E130.OE149.3E1+900E]4801E1*7.2E}*5.5~]+4.bE]43,YE1+3.UE142.5E142*IE]41.3E1+0.6E]3d.7E]37.2Elsb.uE13504E134.8E
]S4*5E1J2.4E13Z.lC13104EJ5(J.OE[.29.*E]30.OE1.?9.4E1Z9.OE129.OE]ZH04E1<6.9E1/6.0:
SLTLSSLTLS54-P----%5
54-P -.---,., 3SL rLS54-P ----OR54-P----03SLTLSVW-P----10VW-P----OS54-p----L554-p----o4
SL’TLSVW-P----(),V(4-14----(I754-r ----(,%54-p----~,J
>LTL>VW-R----1,1VW-K----USv~-~----()~
VW-K----US54-p----,, 754-p----,,7
54-P----1)7S1 TL>v@l-14----l?ov~-~----u~vw-~----lov~-p----l)~s4-p----,)~
54-P----U+
5LrLSv~-~----(j7
VW-R----4)7v~-*---- 7b4-v----u?34-P----0254-P----07SLTL>VW-K----?%VW-H----?(IlJ*-p----l~vw-1+-..--~,,Vw-<----,,q
V.!-H----(J554-* ----11)54-P----(J){
srG YSTG d
u43 u,.1
11460*srG c
?00’41{700%
STG C032(JFIl)zli)..IOU%700’41.5
STG !(0990,,!
700M!.3010,.
>rG x
700%31UO!..7uu~l-
STG x
foum-’700’4,,lUI)+l
STG X
7UOY!T(JOMr$7ou$’1*
slG &
UAA19i AUdllUJ.2uIAU35U>2VIA(JJO---
(JIOU(OIJIAlUO---
lUOLV3IJIA------------130IdolUUuIA------------
1U5112uIA------
----
1L5Luu1<5dill------------------
1U5
U(5
-- W)!j --- i+l’)s-
U15 999(Idkl 996
-- HNI)S -41*U 994(,)b5 964
-- nqu~s -1145 9t9,105 974,lb5 911lldu ~bO
U3 H$4>S dIuo 9>5------
lUU ~Y45lio f 937
U3 84{s 3--- J#f--- ------ @------- ----130’’’” ‘+03)Ju -900lJU !396
Uri t<,i,(j j--- ---,)05 ------- .-- - - ---
13U 89b)5(J ki9u
UJ h{g>5 .+--- ------- -’----- ---
JJ(J +lHI 5U 91+13(J 9<1
ur> H4:)S 4
-- - -- -
---- --
--- ;h 8
- -- -- -
--- ---
---- ---
--- 950
Iuo <j-j &
“t-,”
--- 2)3/240,---,A’l. dti/i52&5b 2u/12--- .21)/Ji?~,.
--- --/*-/--- -- .-
---- --/---,..,2(!4FI c!3/123143” lf’J/lu3140r~l” .2fJ/llJ
0,
-------,!
A)4------
(---.,”
2b49 :,-
/----/----
r?l/J3/-- .-
--/--/-- .-
<u/ltJ
20/1+
--------
----------------
----,*C-3N
r’ii->t----
------------------.--------
--------..------------
-------------------------
----------------------------
F.t4.~.h.
-..--
Id------
12Iu--
()u
--I.1I--(Id----
(1‘2
--(lb
,) 9il V(IU(1‘3
~,,:
!!11
11
11
II
IIItt
III
t.nl
II
III
II
litI
ItI
1-1
1I
II
It
IIIIIII1’IIIiiIf”J!
!trl
11
-1IIJ
I1
.i
I1
11
1I
II
1)1
1t
I1
31
@a
1m
81
,m
*4
1#
IE
S*3
1\\\\\\\\\\\
\\\\\\1
IIII
III
It
I*
I1101
tf1It
I*
IIItIII
In!
IIll
II1\
I1!1
II
t~I
1$
11
III
IllI
III!II
III
II
II
tII
Illt
III
ai-IFX
+-1
13
-l>le
c)
k_ll--
1v)
1
CY
x,.
-
F?
Oc
Zz-l_l
I1iIw1=
1>
1-
Ia10t%
lI
-J.N
NN
*r.
3=
0“‘-u
I
5-36
TYPHOOiX GRACE - 09/29/23002 TO 10/06/23002
I. DATA
i%. STATISTICS1. NUNiiER OF WARNINGS ISSUED - 29?4. NUMBER OF WARNINGS WITH TYPHOON 1NTENSIT% - 213. DISTANCE TRAVELED DURING WARNING PERIOD - 2172 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 937 MBs AT 032130z2. MINIMUM OBSERVED 700 MB HEIGHT - 2548 M AT 03213023. MAXIMUM SURFACE WIND - 095 KTS (FROM BEST TRACK)4. L~XIMUM RADIUS OF SURFACE CIRCULATION - 300 MI
II. DEVELOPMENT
A. INITIAL I.MPETUS - A COLD CORE LOW BECOMING WARM COREAFTER DEVELOPMENT OF DIVERGENCE AT 200 MB
B. INITIAL SURFACE VORTEX1. COLD VORTEX AT 28000022. SURFACE PRESSURE LESS TH71N 1012 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - VARIABLE2. UPON REACHING TYPHOON INTENSITY - ANTICYCLONIc
III. FINAL DISPOSITION
A. BECAME EXTRATROPICAL
5-39
U&
..
.
~“””i .,......b8@
a‘T
””’
i:,.,
q!
—4
——
+.
,$:
?
-t-&--
;$l:G
..
“\”!!i
““#i::::~
:::#,.,
.:W
-4:::”Y:::
::::1
/:-t
I1,
II
IL
‘II
1“
hit-
.:::1:..
p ...
..
.~..,:~
;:::::+
‘~::::]:
’:”]’”’”~ ..
./’
I
R:::
C:::
I:-::.L
::U
:::1
..
..
g-
*3
P* “
6.
0:
0’”*-,
.o
.+.
..
..
%i)ii-”4””””1
tN~’::’s--- -
1
0s
5-40
1=
1
T
Id
—
u
—!5w
—--%w
—2
—
u
—!2w
—s
TYPHOON HELEN - 10/08/05002 TO 10/12/23002
I. DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 202. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 1(,)3. DISTANCE TRAVELED DURING WARNING PERIOD - 2340 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 930 MBs AT l10300z”2. MINIMUM OBSERVED 700 MB HEIGHT - 2481 M AT 1103OOZ3. MAXIMUM SURFACE WIND - 105 KTS (FROM BEST TRACK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 330 MI
II. DEVELOPMENT
A. INITIAL IMPETUS - 200 MB ANTICYCLONE OVER THE SURFACECYCLONE
B. INITIAL SURFACE VORTEX1. JUNCTION VORTEX AT 06060022. SURFACE PRESSURE LESS THAN 1007 .MBS
.
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - ANTICYCLONIC2. UPON REACHING TYPHOON INTENSITY - EAST
III. FINAL DISPOSITION
A. BECAME EXTRATROPICAL
5-45
ulIlbm
110. 11s. 120’ 125. I 30. 13s. 140” 143’ 150” 1s5” 160’ !85” I 70. 175” E., tLm@!@ 180.
‘.4, ‘J21Y I J“*’ I x“ I I I ]Iefaz I tP-’l-
t ‘iii .?./+’’-” +.
1“””tlW%
I II III i
. . . . ,,
“1. . ,.! (x
*
,..* ‘-*WMTY— ~T~~N Q~ TFOPICAL. .8. ””- ‘-TROPi~L DEPRESSION.,.
~ @ FORMATIVE STAGE. . . . ., ’11++-+-,.,,..
tti.-1-4- k--.1 .J— + -f--+
‘ ‘7,., . ,.- -:::--- - [’+-k +-- -
~+
'+H;:Ff'~+fl L''`'''`':''''''''''''':'''''`'''''''':"''::'“i”t””t ”””” t””” ”t’’”’t’””t” “.”}”’+”” “:r=--n-+-”’~-F+---t-,.!fJ,,,,~,4,&+..,<%fl,,::,:l,w:,:::,l,:=:@m:::,:wq:,l;::i,,till,,,,,
-ii=..-L. . ..-.
‘2:1 :”:: :1:: ::1:::: 1::: :1:: ::1: :0::::1: :”::c!.:t::::t.i! . . . ...g . $0.,_..-?-----. . . ~.;,7 028””
00 7: ,-3 ....... . . . ..,,-,
‘. .WJ.J. . .. LJ . . ..L... .1 ..r. .d . . ..d-. . ..l.. .. J-....1. .1*.1....1
,
TYPHOON IDA - 10/15/23002 TO 10/22/05002
I. DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 262. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 173. DISTANCE TRAVELED DURIIJG WARNING PERIOS - 1296 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 917 .MBS AT 17205022. MINIMUM OBSERVED 700 MB HEIGHT - 2384 M AT 172050Z3. MAXIMUM SURFACE WIND - 115 KTS (FROM BEST TRACK)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 360 MI
II. DEVELOPI~IENT
A. INITIAL IMPETUS - DEVELOPMENT OF DIVERGENCE AT 200 MBOVER SURFACE CYCLONIC CIRCULATION
B. INITIAL SUF!!ACE VORTEX1. JUNCTION VORTEX AT 13180022. SURFACE PRESSURE LESS THAN 1008 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - SOUTHWEST2* UPON REACHING TYPHOON INTENSITY - SOLJTHWEsT
III. FINAL DISPOSITION
A. BECAME EXTRATROPICAL
5-49
.
mmmi::::::: {z!!5.ii z:s2 +—t+ --t-----t --+i----i:-+---+-+—, ,,wcn:u/---t-- t-----i-–+--+- -i-+-–+--+--+—*+t-
AllSN31NT#+* n7-1,C.
l“””l””” ,,.3N073A3
.~.Tj-, .,,, ., ,:.,,,,,““H
w,.,
......,..,
!4
Tjv-T--Zz91.
.01””””
f...IT
.’-.2““”’”””9N69,,..
.Uoz.z.....
Ozl
I
.Cz.c.
<,&.....
r,,,T::o.;:L” t....
1::.:t::..’::;;t:t””T””’’”’t’’f*~:;;”].;o+::t”x’b-=’~~’”i: .,*.,.!.!,,,,,w,l_#_.,..,,,.-,,-
LYE FIXES CY(:LU14E 19(IN1 r- F“LT
FIXl)tls 05s M1,.$ OL r I dr\NS
MFTHt)IJ FLT LvL SFC r.tlpl /UOMd (.VL LYE u“l’ilLN- tYt,Nu. TItiL POST I
WALL-4CCY LvL wli~ .N() SL P tivT 1“/10 tuu:l r{k(ldi~ l_)[A CLuul)
------ ------- ------- ------------- ------- ------- .------ ------------- ------ ---y--- ---------------- ------ ------- --13.(JN
14.ON
14.71*
14.9N
14.8,4
14.814
14.71+14.914
SLTLSSLTLSLN[) H!)KLNO ut,~LNI) l{,IRLNO +lj~54-p----04
54-P ----,]4
STG A LIIASTG A UIA
---
-. tiNIIS --- tiriqs---- --- --- /----
/----/----/----
2!/~5~!/~~
I-. --I-- --
-./--
I-.. ----/--
2I/d72!h/db
--------
k.ti.F-*H*
---.------lbIu----
-.
lU()o,1nJ &
u e--
(J3(1>
------
Iu[) ?(J5urn
--
07L1810--
-.b.boF.h,N.F*b.N*F-*b.
--- --- --- ------ --- ------
---IJ’300PI0>50390r/f U>8
----
-,.I .,
.. ‘-
----------------
----------------
----------------
------------------------
-------------.---
--------
--- --- ---(JJ5 0U5 ---(IJ(J 002 ---
IJ.5N15.2(414.8,*
i3.9N
15.814
13.5N
15.81*
lb.UN
lb.4N
lb.9N
11.5N1(.lm1[.7,4
~44,0E145.4E144*9E1450ZE144,YE145.oE145017E144.tiE144*7E144.7E
1+5.*OE144.6E144.8E
S1.TL3 STG S
LNI) HI*Qv$J-N------
LNLI KI)RLNI) R(IR
VW-K----O%
VW-P----OS 0300.1v#J#----],) 03201.,~~-p----,)~ 700%154-p----o~ 7uu!4dSLTLS ST(3Xvw-~----(,bj
VW-K----(,3
I)LA------
-- f3NDS------ ------ ---
------
--- --- --- ----------
------ ---
----------(.)37(J54VIA--- /--- -- --
/--- -- --lH.014 145*oE v#l-~----()~ --- --- --- ~ --/-..--*,;1?$.614 I+504E 54-P----(J5 700Mh UM5 (Jill 911- C?SH4’ 24/ue
1~.~N 1*5.lE 54-P----05 fout.lfi llU Ilo 918 2+02 c!4/u9
19.U14 ]45.5E SLTL5 sr~ x UIA U.] I+N)S +i9.ti14 l’tb.8E v~-~-.---u,~ 0400,.)Uoo (1>() ---
--- --- ---
WIIU-IF Zu.c?d 146*1E v#:f-l{----
54-+---::7ou~lt --- --- ---
21.0,4 1+6.bE “700Mt$ Ufo l)~u 91921.61+ 146.tiE 54-IJ----I5 7UOM*$ 110 1190 9d9
+7.(JF46.2E47.UE+7*6E47*4E45.OE46.2E+8.2548.(JE*8.6E49.6E00.HE3(J. 7L
sLTLs SrG Xv$j-~----l,)v’#-R----(J~
Vw’-ti----l%vw-l’k---l~ ruo~lf54-P----,~ 70(J’’I-I5,4-P---- i5 7ou49b54-P----26 7(J(J%%sLTL3 Sfti xvw-~----~~
vN-ti----l)5vw-N----lj754-P----10 7U(JVH
VIA------
u$ bN,]5 4---- ---
--- ------ --- ----U(LI
1001<0IL(JIJkA---
VUN ---
:1{(J ---
IJo 9*4
------1s0
54-P----10 7ooMr,SLTL5 Sr(; Xvw-n----~s
VuJ-P----lo 7uuqr>VW-P----1,),4-V----IS 70UY-I54-F’----2o 100Mj5LTL> Sll; x
--- 130 Y*3LJiA U> BI*I)$ s--- --- ---
--- (I3U 915--- --- ---
u9Ll (loll 938Ulo 000” 9/1uIA W> n143s 3
TYPHOON IDA
TROPICAL CYCLONE19 -- 10/15/23002 TO 10/22/05002POSITION AND FORECAST VERIFICATION DATA
24 HR FCST 24 HR ERROR 48 HR FCST 48 NR ERRORLAT LONG DEG DIST LAT LONG DEG DIST—— — —
WARNNO.
030405
06070809
WARNING POSITDTG LAT LONG— —
72 HR FCST 72 HR ERRORLAT LONG DEG DIST— —
1611OOZ16170021623002
15.7N L44.7E16.2N 144.5E16.6N 144.513
15.7N 144.9E16.2N 144.8E16.6N 144.7E
17.2N 144.8E17.8N 145.OE18.3N 145.2E18.8N 145.5E
19.4N 145.7E19.9N 146.OE20.6N 146.3E21.2N 146.6E
21.9N 146.9E22.6N 147.3E23.3N 147.6E24.lN 148.OE
25.ON 148.5E25.5i~ 149.4E26.2N 150.2E27.lN 151.2E
28.lN 152.4E28.9N 153.6E29.7N 154.8E30.7N 155.9E
31.8N 157.OE
18.3N 142.7E19.ON 142.9E18.3N 143.6E
19.7N 145.3E20.3N 145.3E20.5N 146.3E21.3N 148.lE
21.9N 148.9E22.8N 148.6E23.ON 149.OE24.lN 148.8E
24.5N 148.2E25.5N 148.31?25.6N 148.3E28.2N 151.OE
29.7N 151.2E28.4N 150.7E26.7N 155.7E30.ON 154.8E
31.lN 159.lE31.5N 160.7E31.7N 161.3E
AVERAGE 24 HOURAVERAGE 48 HOURAVERAGE 72 HOUR
21.3N22.ON20.lN
141.4E141.9E142.6E
----------------256-0120
219-0114283-0126288-0132255-0108
314-0024303-0042180-0006086-0078
090-0108081-0072104-0072090-0042
202-0030270-0054252-0108354-0066
327-0108259-0150165-0186233-0066
112-0108
------- -------- ---------
25.8N 143.lE
25.7N 153.6E
25.4N 154.6E
28.ON 161.6E
31.ON 161.lE
30.6N 155.2E
32.6N 152.5E
----- ---------- --—------
----------------_-—_____________
--------—-----------------------
-------------- --301-0288------ --
082-0276--------101-0234--------
090-0486--”--- --077-0330--------
232-0114
17050021711OOZ17170021723002
180500z1811OOZ18170021823002
17.2N 144.7E17.8N 144.6E18.2N 145.lE18.8N 145.6E
22.8N23.2N23.3N23.6N
147.9E148.3E149.5E151.8E
------ ---—-—----------------- ---
U-II
10
w11
N 1213
19.4N 145.9E20.lN 146.lE20.5N 146.3E21.3N 146.7E
24.4N25.5N25.8!?27.l)J
153.7E153.4E153.8E152.9E
-------—288-0270289-0252254-0228
046-0072057-0060090-0102098-0204
097-0282090-0216097-0192090-0090
251-0108269-0204257-0282006-0126
331-0132
14151617
18192021
22232425
26
19050021911OOZ19170021923002
21.9N 146.9E22.6N 147.2E23.lN 147.4E24.2N 148.2E
27.5N28.8N28.6N32.8N
150.4E149.7E149.5E156.2E
20050022011OOZ20170022023002
2105OOZ2111OOZ21170022123002
2205002
25.3N 148.5E25.8N 149.OE25.5N 151.OE26.9?4 151.OZ
33.8N30.ON28.2N31.8N
155.71?152.8E160.2E161.lE
28.2N 152.6E29.lN 153.9E29.6N 155.OE30.5N 156.4E
34.3N32.8N
166.8E169.OE
31.5N 157.2E
ERROR - 0087ERROR - 0176ERROR - 0288
MI.MI.MI.
TYPHOON JUNE - 10/28/0500Z TO 11/05/05002
I- DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 332. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 213* DISTANCE TRAVELED DURING WARNING PERIOD - 1782 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 936 MBs AT 020820z2. MINIMUM OBSERVED 700 MB HEIGHT - 2643 M AT 02142023. MAXIMUM SURFACE WIND - 105 KTS (FROM BEST TRACK)4. MAXI14UM RADIUS OF SURFACE CIRCULATION - 500 MI
II. DEVELOPMENT
A. INITIAL IMPETUS - 200 MB ANTICYCLONI? OVER THE SURFACECYCLONE
Be INITIAL SURFACE VORTEX1. JUNCTION VORTEX AT 260600z2. SURFACE PRESSURE LESS THAN 1005 MBS
c* 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - SOUTHEAST2. UPON REACHING TYPHOON INTENSITY - ANTICYCLONIc
111, FINAL DISPOSITION
A- BECAME” EXTRATROPICAL
5-53
----------------
-----------------------------------------
----------------
------------
----q-w
>C-MN
Yq-mhi
+1/1101/0?llT/o?
/ ----
0.?/9?/ ----
*l/E?91//1tl/LT
/ ---.
?.?/+zfT/flr71/RToT/--17/*i?Tz/*7!
I ----
zI/nz+1/H[+T/RIG.?/s?
/ ----
/ ----
?T/lTz91/02--/--
/ ----
*l/flT01/91s?/i?.-/--
Q,?/R?/ ----
FT/&l?T/~TIll/*l?.?/+,?--/f-I
/ ----
c7/~~--/--
/ ----
66F17.L’4~z
L5ii?---------
6tii, i!FJ~~~c~f?7.------I!ELZ91&ZE*97---
0i16SQO0/6---016---------’396Sal)------+~u~g*O
S%07[E96---9G6---------E96001196;{;6~6++6---
f)fllSaflqQfl----------VT(I071f.’$10Gafl----
Sflo~QflOaonnT
02---+-*SSO---+-MA
so---+-MAOZ----CPMAso----~-MASI----d-MA
Sillsso--.-d-*sHo----d-+<ZO----#-MAso----~-fl~
Zo----cj-hAso----d-mStl----4-*S
EO----d-klA9F6O“T1---wowo‘SO----d-t4A3S*1F1N+*OI?
:::~’::~”)OTI---, ------+JSuMf(FIIVT(T
9*9?S*600TOTT91$??996------9[9Z996------0s9?*’46l’)~fl---------------------------
rSwdflFTIVTflEHLZZ9607[0606GRZTL6---Oeo------------------------
7.SuNRcnvTr7L*RZC16E.)(1oanOlil?9L6)---S)n*?nr6)6SC()----------Cj+()Sro----TfkS*I)---------q+()O*O
-$~!~q‘-VT(l
‘=IFA?t?f?6\oqnOanrs67~i7Q6L+~7
,iR6\s~~’sc~---%+0
---;(5R6OFO---Z)OF‘-1A6oro”Rcll-------------
-SUNFI--Wl(l---666nrjl**(l---InoG?(I”---
-sbh)ti--Vlfl---*OO()?0---
-sj(lrup--Vlrl-------------------------------------.--------------------.-----------------.-----------..------------
LA
TYPHOON JUNE
TROPICAL CYCLONE 20 -- 10/28/05002 TO ll\05\0500ZPOSITION AND FORECAST VERIFICATION DATA
BEST TRACK 24 HR FCST 24 HR ERRORLAT
48 HR FCST 48 HR ERRORLONG LAT LONG DEG DIST LAT LONG DEG DIST— — — — — —
72 HR FCST 72 HR ERRORLAT LONG DEG DIST——
WARNINGPOSITLAT LONG— —
WARNNO.
0708
09101112
13141516
17181920
21222324
25262728
29303132
33
DTG
291700Z2923002
30050023011OOZ30170023023002
3105OOZ3111OOZ31170023123002
O1O5OOZOlllooz01170020123002
0205002O211OOZ02170020223002
030500ZO311OOZ0317002032300Z
0405002O411OOZ041700Z0423002
0505002
11.7N 132.6E12.2N 133.OE
12.7N 133.2E12.8N 133.8E13.5N 133.9E14.2N 133.7E
14.8N 133.7E15.3N 133.8E15.8N 133.7E16.4N 133.4E
17.ON 133.2E17.8N 132.8E18.6N 132.5E19.4N 132.2E
20.ON 131.7E20.6N 131.4E20.9N 131.3E21.3N 131.lE
21.8N 131.lE22.4N 131.2E23.ON 131.6E23.7N 132.3E
24.8N 133.4E26.2N 135.lE27.7N 137.lE29.2N 140.OE
31.5N 143.3E
12. 4N14.lN
130.5E133.7E
305-0270273-0198
247-0132271-0258252-0204180-0006
038-0066134-0072123-0084107-0078
095-0066064-0048098-0078099-0102
106-0102111-0096063-0114046-0108
051-0138033-0096034-0060255-0126
230-0192237-0204233-0246234-0312
246-0318
11.6N 131.4E12.2N 133.lE
12.9N 133.2E12.8N 133.7E13.2N 134.lE14.2N 134.OE
14.7N 133.8E15.5N 133.5E15.8N 133.6E16.5N 133.5E
17.0:{ 133.41z17.6N 133.OE18.8N 132.5E19.5N 132.3E
20.2N 131.8E20.8N 131.4E21.ON 131.3E21.5N 130.8E
21.5N 130.9E22.4N 131.OE23.ON 131.5E23.5N 132.2E
24.7N 133.2E26.2N 135.2E27.6N 136.9E29.2N 140.OE
31.3N 143.6E
16.lN 134.OE---...-----------
------------------- - - --------- --
------ -.----------------269-0540
054-0222120-0186126-0210115-0216
098-0234081-0210083-0216075-0270
080-0192083-0.192070-0270059-0204
026-0096314-0042260-0096244-0600
236-0810
139.7E
136.2E
138.7E
137.3E
137.3E
140.lE
137.4E
139.5E
131.7E
139.7E
----------—-----
-.------------------------------
----------------------------..---
--------------- -----------------
068-0480--------
122-0324--------
086-0420--------
072-0324------- -
078-0210--------
086-0156--------
249-9324
136.4E135.7E135.5E135.7E
23.lN
18.ON
15.7N14.4N15.ON16.ON
134.5E134.8E135.OE134.8E
19.2N16.2N16.5N17.8N
134.4E133.7E133.9E134.lE
19.4N21.2N21.4N22.5N
135.9E135.2E135.2E135.9E
22.4N
24.7N
16.9N18.2N18.4N19.lNul
Am
134.6E134.7E136. 3E135.5E
25.6N19.5N20.ON21.8N22.6N
133.6E133.lE133.2E132.5E
22.4N22.8N24.6N25.5N
27.9N
23.3N23.EN23.9N23.lN
132.lE132.2E132.3E130.OE
26.3N26.7N27.4N24.7N
134.2E134.5E135.2E129.9E
29.5N
30.9N
22.71424.3N25.2N26.lN
130.6E131.9E133.4E135.2E
23.9N26.8N27.7N29.3N
130.7E134.2E136.lE139.4E
25.7N
30.7N
29.3N34.4N34.6N
137.6E144.8E144.9E
34.2N 144.8E
MI.MI.MI.
AVERAGE 24 HOURAVERAGE 48 HOURAVERAGE 72 HOUR
ERROR - 0139ERROR - 0267ERROR - 0319
t A
TYPHOON KATHY - 11/03/0500Z TO 11/08/2300z
I. DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 242. NUMBER OF WARNINGS WITH TYPHOON INTENSITY - 193. DISTANCE TRAVELED DURING WARNING PERIOD - 2040 MI
B. CHARACTERISTICS AS A TYPHOON1. MINIMUM OBSERVED SLP - 930 MBS AT 07210f3Z2. MINIMUM OBSERVED 700 MB HEIGHT - 2478 M AT O721OOZ
MAXIMUM SURFACE WIND - 110 KTS (FROM BEST TRACK):: MAXIMUM RADIUS OF SURFACE CIRCULATION - 420 MI
II. DEVELOPMENT
A. INITIAL IMPETUS - DEVELOPMENT OF DIVERGENCE AT 200 MBOVER SURFACE CYCLONIC CIRCULATION
B. INITIAL SURFACE VORTEX1. JUNCTION VORTEX AT 020000Z2. SURFACE PRESSURE LESS THAN 1006 MBS
c. 200 MB FLOW ABOVE SURFACE VORTEX1. INITIAL - NORTHEAST2. UPON REACHING TYPHOON INTENSITY -“ANTICYCLONIc
III. FINAL DISPOSITION
A. BECAME EXTRATROPICAL
5-57
+
“t’;
-+$
ml>
7_IL”
“t’-
l&_,
+m
-k.-L.
.,.
tt
,,...,.W ,....
$...
,.,
i ~?...,
.,.
..
,.
,..
..
.,,t’ ;+.........
t
.
!I
11-!it
I14__#
-.
.:
J:....;
.l.~-;
F’
-4
..
..
..
f---li’
I :-
1;0.,
II
F’&-~
%
..
7
5-58
ANNEX
A
SUMMARY OF TROPICAL CYCLONES
IN THE
EASTERN NORTH PACIFIC OCEAN
FOR
1969
.1 .. . . . . . . .!.. . . . . . .
140”. . . . . . . . . .
. . . . . . . . -.. ,. . .
t 1 1 t I I , 1 I 1 1 I
. . !.. . -1- . . . . . .
+... .
+,., .
+. .
f,,, ,,+ ,
!,lfQi*#HER ‘ + o “
. . . . . .,.9 . . .
\-t-t-
-.
. . * . . . . -L . . . . . . . ,
. . . , . .,. .
1 , , , , , $ 1 , t , I ,,
. .
. .
. .
. .
, , I
. .
.,
. .
1 , 1
. .
,,
17.la.”i;”
+:-- - -- - ~ ~ ~ ~ ~ ‘.% .“=L:,W$: : :;?,W“)‘, 1 I t t , tr , I 1 *-~+i;3&’,, r
.+ . . .. J.. ..X ... ._ . . . . . . . . . –.. -.:. %:?,ESW ..”:
i’“ omf&%T ~, g. _. . !’”. “;8,4<; ?’;_
~. K.v.-an,,., .,. - x,~, t p - —,0-- ~y-. - —. —cA~.””.2Z0?, 38,0“6
I 7 ,,.r-o==-z;-”o” “‘“ ““’“-ri
2gQfii~vij-.3iF’’””~ ‘ “4”” - - ‘-- p “’””3’””-” F ‘Tf-$l
3+, ..OOO;~3%?{ ‘~’”~ T~oP/CAL STORMS
“ Fcu ~ ~,oo O’N V*~,, ,U Oomu -’11. ‘“ .,3?1
“ WJNZJ,o “t”, ;“,
,..
I IF
00 C“;u, ~ TROPICAL DEPRESSIONS ~:%t g, g: tax . m {“M. ‘g’@
.z,%J:\” -$, %.. . . .sm. o . .\ ~
~ 0s4 ~ ~FHI EASTERN NORTH PACIFIC ;.!. . . . .
“ \“ b w:o
, r
. . .
. . .120”
,, !
. . .
,!,
. . .
,,.
K@! . .. . . .t
\ N“ ‘ “ “ “’”” ““” _., ,,- - , , . “’A#’74: , $;,. . . . .‘s,” ‘ “ -v”””- -“””’- -.. .
. . . . . . .. . . . . . . . .-.I , \,, ! I 1 1 , I 1 I 1 I i , ,, 1 , I , 1 , , , 0 1 , , , ,
. . . ,.. ●
--PT4?2, .
., . . . . Iiir HER: : : -_: :::- .: :::- _~aew_:-.~~~oz. . . . . . . . . . . . . . . . . . . . ,.. . . . . . . . . .
. . . . . . ,.. . . . . .,. . . . . ... . . .1 , , }10”+
#, , , I , , t , , , , I i 10”; , I , , I , I 1 ,, ,I ,
. . . . . . . . . . . . . . . . .. -., ,,, . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .140“
. . . . . . . . . . . , . . . .. ,..12o“
TD -0’”””/ ?Y..
. . . . . . . . . 100 “. . . . . . . . .,, . . . . . . . . , . . . . . . . . . . Tpor
. . . . . . . . . . . . . . . ,.. . . . . . . . . . . . . . . . . . . . .
I 1 1 1 , # I 1 , 1 ! t 1 , , I , , I 1 1 I , , , 1 1 1 1 ,, , 1 , 1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,.. . . . . ,
.,. . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . .
. . . . . . . . , .,, . . . . ..
. . . . . . . . . . . . . . . , . . . ,..
,. . . . . ,.. . . .4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .,, , ,,, , ,,, , ,,, , 11, ,.,“e
,.,,,,,,,,,.,.,,,,-*........................,,.,.. ...........
.........................,..,,..........,.............................,,.,......,
........................................
,,rr,I1r8,aI1,,r,r,1,,,1I[I11t1I,,IIr
..............!......................,.,
..................,.,..........
.001......
.0?!.091.................,..................
,,,,1tI,i,t,,taI111,,,,t,I1,II11I
f-+-rrrr-r-t-~4+.... .............................,...,,..... ;.01:;.01;
#.01
.....,,..,.4....!,...,...,,!............
During the 1969 EastPac Tropical Cyclone season, Fleet Weath-er Central, Alameda, issued a total of 219 Tropical Warnings onfour hurricanes, six tropical storms and five tropical depres-sions. No tropical cyclones originating in Fleet Weather Central,Alameda’s area moved out of the area. The 15 tropical cyclonesidentified this year is the lowest number since 1965 and thenumber of warnings was the lowest since 1964, reflecting an un-usually inactive season. No specific reasons for this apparentinactivity have been determined.
The following eight year summary covering tropical cyclonesoriginating in Fleet Weather Central, Alameda’s area of responsi-bility is presented for comparison. Included are warnings issuedby Fleet Weather Central, Pearl Harbor, when the tropical cycloneoriginated in the Alameda area.
Total Numberof Warnings*
Calandar Daysof Warnings*
TropicalDepressions*
Tropicalstorms
Hurricanes
Total TropicalCyclones*
1962 1963 1964—. .
122 80 60
35 26 21
6 ~ 4
2 4 2
8 9 6
1965
244
73
2
9
1
12
1966
342
70
6
6
7
19
1967
474
119
.2
12
6
20
1968
531
126
6
13
6
25
1969
219
67
5
6
4
15
*Tropical Depression information not available 1962-1964
Jennifer was the only tropical cyclone that caused damageon land. One person was killed, 15 injured and a large ferryand 12 shrimp boats were reported swamped at Mazatlan, Mexico.Thirty other shrimp boats were reported lost in smaller harborsnearby. There was extensive property damage along a 100 milesection of the coast but information on money amounts andspecific losses are not available. The highest reported windsat Mazatlan Airport were 50 knots with gusts to 70 at 21OOZ,11 October.
Forecasting tools used included twice daily readouts of theFleet Numerical Weather Central’s ‘J~TmcKjf steering program,extrapolation and subjective reasoning. While a definitivestudy of the various techniques has not been made, the lattertwo methods, coordinated with the Hurricane Warning Office,ESSA Weather Bureau, San Francisco, appear to be the most suc-cessful.
AN- 3
This season marked the inauguration of U. S. Navy respon-sibility in the Eastern Pacific for tropical cyclone recon-naissance. Efforts were limited by resources (two EC-131 air-craft and two meteorological crews operating from the PacificMissile Range, Pt. Mugu, California) and no routinely avail-able staging points from which to base aircraft to coverdistant storms (more than 1200 nautical miles from Pt. Mugu).Early in the season Acapulco, Mexico was used but 48 hoursadvance notification was required. Later in the season, limit-ed funds precluded the use of Acapulco except in an emergency.Because of the aircraft configuration (EC-121 vice fiC-121),penetrations could not be made and low level eye data was notavailable. The USAF continued to fly tropical cyclone recon-naissance missions in addition to scheduled Navy flights.High level reconnaissance data are available from that source.
Limited resources, coupled with the great distance at whichmost of the tropical cyclones were found caused APT data toremain as in previous years, the primary source of fixes. in-sufficient reconnaissance data were available to make any mean-ingful verification of tropical cyclone intensity estimatesbased on satellite pictures.
TROPICAL CYCLONES FOR THE 1969 SEASON
ORIGINATED BY FLEET WEATHER CENTRAL, ALAMEDA
0102
030405060708091011
12131415
CYCLONE
Tropical Depression 01Tropical Depression 02REGENERATEDTropical Storm AVAHurricane BERNICETropical Storm CLAUDIAHurricane DOREENTropical Depression 07Tropical Storm EMILYTropical Storm FLORENCEHurricane GLENDATropical Storm HEATHERREGENERATEDTropical Storm IRAHTropical Depression 13Tropical Depression 14EIurricane JENNIFER
3104070208210409220208182330030308
PERIOD
May 1969June-05 June 1969June-08 June 1969July-07 July 1969July-17 July 1969July-23 July 1969August-09 August 1969August 1969August-24 August 1969September-07 September 1969September-12 September 1969September-22 September 1969September-25 September 1969September-03 October 1969October-04 October 1969October-05 October 1969October-12 October 1969
AN-4
Below is a summary of aircraft fixes made on hurricanes andtropical storms during the 1969 season.
CYCLONE
DOREEN4-9 Auq
E~IILy22-24 Aug
FLORENCE2-7 Sep
GLENDA8-12 Sep
HEATHER18-25 Sep
IRAH30 Sep-3 Ott
JENNIFER8-12 Ott
DATE/TIME DATE/TIBIEREQ. FIX P~}lARKS
061800Z 061730Z071800Z 071800z USAF FIX ALSO AT 071800z
071800Z081800Z 081905Z
240000Z 232300z USAF FIX ALSO AT 231840z
0318002 031755Z050000Z 042340z USAF’ FIX ALSO AT 041824z060000Z 052315Z USAF FIX ALSO AT 9517322080000Z CANCELED USAF FIX AT 061805Z. NAVY
RECON CANCELED DUE STORMDISSIPATION
091800z 091800Z USAF FIX ALSO AT 091748Z11OOOOZ 11OOOOZ USAF FIX ALSO AT 10173OZ120000Z 120030Z USAF FIX ALSCI AT 111713Z
NO NAVY RECON REQUESTED USAF FIX AT 201825zUSAF FIX AT 211809Z
011800z ol1900z USAF FIX ALSO AT 0118002030000Z NO FIX ACFT FLEW BUT UNABLE TO
LOCATE DISCERNABLE CENTER
11OOOOZ NO FIX ACFT NOT AVAIL FOR RECONFLIGHT,USAF FIXED AT 091800zAND 10174OZ
120000Z CANCELED STORM DISSIPATED. USAF FIXAT 111800Z
A total of 15 requests for Navy reconnaissance were madeand two were subsequently canceled. Of the 13 remaining requests,only one could not be met and that was due to non-availabilityof aircraft. Twelve Navy reconnaissance flights were made.During the same period the U.S. Air Force 9th Weather Reconnais-sance Wing flew 14 missions.
AN-5
DTG
3106OOZ311200z
DTG
041600Z041800z050000Z
**07000(-)Z*070600z
071200Z
DTG
090000Z090600Z
DTG
031800Z040000Z
TROPICAL DEPRESSIONS 1969POSITION DATA.
TROPICAL DEPRESSION ZERO ONE31 MAY 1969
LAT LONG DTG LAT
07.8N 90.4W 311800z 08.2Y08.ON 92.OW
TROPICAL DEPRESSION ZERO TWO04 JUN - 05 JUN 196!3
LAT LONG DTG LAT
11.5N 91.OW *071800z 13.ON11.5N 91.3W 080000Z 13.5N11.5N 92.OW 080600Z 13.7N13.5N 102.5W 081200Z 13.7N13.ON 101.OW 081800Z 14.ON13. 3N 102.OW
TROPICAL DEPRESSION ZERO SEVEN09 AUG 1969
LAT LONG DTG LAT
18.ON 106.OW 091200Z 18*6N18.4N 106.8W 091800Z 19. 8N
TROPICAL DEPRESSION ONE THREE03 OCT - 04 OCT 1969
LAT LONG DTG LAT
20.ON 107.OW 040600Z 22.5N21. 2N 106.8W
TROPICAL DEPRESSION ONE FOUR03 OCT - 05 OCT 1969
DTG LAT LONG DTG LAT
031800Z 11.ON 95.5W 041800Z 13.ON040000Z 11.5N 97*3W 050000Z 13.5N
LONG
93.OW
LONG
104.5W105.OW105.7W106.OW104.OW
LONG
107.6W109.OW
LONG
105.5W
LONG
97.OW97.5W
040600Z 12.ON 98.OW 050600Z DISSIPATED041200Z 12.6N 99.OW
*~LO~TED**~GENE~TED
AN-6
TROPICAL STORMS 1969POSITION DATA
DTG
020600z021200Z021800Z030000Z030600z0312002
*031600z
031800Z04000020406002041200Z
*041800z
‘DTG
211800Z220000Z220600Z221200Z
DTG
221800Z230000Z230600Z231200Z231800Z
LAT
13.4N13.5N13.6N13.8N14.ON14.2N15. 8N16.ON16.ON16.5N16. 8N1600N
LAT
13.ON12.5N12.5N12.5N
LAT
19.ON20.2N21.lN22.ON22.2N
TROPICAL STORM AVA2JUL-7JUL
LONG DTG LAT
93.4W 050000Z 16.ON94.lW 050600Z 16.ON95*5W 051200Z 16.ON96.6W *051800z” 16.5N97.6W 060000z 16*7N98.6W 060600Z 16.8N
102.OW 061200z 17.ON102.5W *061800Z 18.5N103.5W 070000Z 19. 2N104.5W 070600z 19.9N105.5W 071200z 20.ON108.3W 071800Z 20.ON
TROPICAL STORM CLAUDIA21 JUL - 23 JUL
LONG DTG
129.5W *221800z
131.OW 230000z132.OW 230600z133.OW 231200Z
TROPICAL ATORM EMILY22 AUG - 24 AUG
LONG DTG
106.5W 240000z106.6W 240600Z107.3W 241200z108.2W 241800z110. 8W
LAT
15.7N16.5N17.3N18.ON
LAT
22.7N23.lN23.6N24.ON
LONG
109.OW11O.OW112 ● 5W111. 5P?112.OW112.5W113.OW11O.OW11O.2W11O.2W11O.3W11O.3W
LONG
133.5W134.4w135*3W136.2W
LONG
112.lW113.2W114*5W116.OW
* RELOCATED
AN- 7
.
Zzzz
00C9W
Zzzzzzzzz
(No=
$I-wr-om
ul●*,*..
.,
m’ooooodr+
dl-ifN
Ncvm
lNN
olN
..
w*b
”i-l-r-ic+l-if-i
NN
NN
NN
NN
00000000
00000000
ow
Nm
ow
olm
Oor+
-loo-lli
No
l(-uo
lmm
t-flm00000000
NN
NN
NN
NN
N000000000000000000
LD
NC
OO
WC
JQ
OU
JO
l+eloodrlo
ol.n
mln
wuw
w*r-
000000000
*
NN
NN
0000
0000
0W
PJU
3O
ol-lrl
oJm
(-4cNO
Jmo
llv*
NN
NN
NN
NN
N000000000
000000000
Cao
w(u
aow
mco
dool-ir+
oorlt-l
mew
wsln
mm
ul
(-ICN
NN
NN
CN
NC
N
:
m0co
I
dill
Zzzzzzzzzz
Lnmocow
oechfim.*.**.
....
comoom
oooooI-II+O
JCJA
(=4N’S
ICJN
Zzzzzzzzz
F3w
r-11-looooo●.....
m’;dw
ww
ww
wF
ir-ll+FiF
ll-lF+F
+d
Zzzzzzzz
Ooocom
eau)o
3“
““*”
wiJ
wdw
”br-t-
I-11-idl-id
dl-11-l
NN
NN
NN
NN
NN
00C
20000000
u0000000000
Hco
ow
rJm
ow
(um
on
dool+l+
ool-lrloN
mm
mm
q**q
ui
0000000000
NN
NN
NN
NN
NN
NN
N00000000000
00
C3
0000000000000
Hao
wm
lcnow
mcn
ow
cqC
AY
n4001-II+
OO
!-14001+d
Cocn
cnm
moooodf+
r-14
riFIF
ld$eJr.J(N
mN
mlm
lC
-4
NN
NN
NN
NN
00000000
00000000
o@
P4m
ow
Ncn
Oot-ld
oor+
dO
ooodrlrid
mm
mm
oo
oo
uHn
INDIVIDUAL HURRICANE TRACKS
FOR 1969
IN THE EASTERN NORTH PACIFIC OCEAN
NOTE : Due to a lack of reconnaissance data, accurate intens-ities could not be determined and thus are not includedwith the hurricane best tracks.
AN-9
HURRICANE BERNICE - 07/08/18002 TO 07/17/06002
I. DATA
A. STATISTICS1. NUMBER OF WARNINGS ISSUED - 352. NUMBER OF WARNINGS WITH HURRICANE INTENSITY - 83. DISTAIVCE TRAVELED DURI?JG WARNING PERIOD - 1994 MILES
B. CHARACTERISTICS
1. MINIMUM OBSERVED SLP - UNKNOWN2. MINIMU14 OBSERVED 700 lwiBHEIGHT - UNKNOWN3. .YUGYIMUMSURFACE WIND - 75 KT (EST.)4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 150 lIILES
II. DEVELOPMENT
A. INITIAL IMPETUS - ITCZ
B. INITIAL SUIWACE VORTEX1. 08180022. SURFACE PRESSURE LESS THAl? 1008 MB
c. TIME STORM REACHED HURRICANE ISJTENSITY - 1218002
III. FINAL DISPOSITION
A. DISSIPATED OVER WATER
NJ-11
. .
.+-d. 14. .
A. .
*
,—
,- ”---
. . . L . . . . ... . . . .SPEED ‘)kI 1 1 1 1 , 1 I I
r1 I
+ ,
I- 1- ---1.....
08-17 JULY 1969MURRICANEOR TROPICAL STLXUI . . - _. . ..- -., ..- - . . .*l\
TROPICAL DEPRESSION .yl . .’$.’-,’, ,y.- .- ~~: y“ . . J , ,’. ,
. . . .
. . . . . . . . . . . . . .
/1 53 w I. . . . ,*.‘~. . . . . . . . . . . . *O“... . ,,, , . . . %$! %3””’:,;;;.,,:?:~oo;:~%. -’
8. . . . . . . . .,, . . . . , .,. . . . . . . . .
+ &j
~{ ~yz ,7, g “ ‘;; NA; ‘ ‘% “t, , 1 t , , , t 1 1 , I i , , , , , 1 1 9 1 I 1 1 1 t ,
‘ ##--+-g ‘“ jyirr=a, , 1 ,&-y. +.-l: m,-1 -
\ ~o.% fj,~~~ %. . . . . . ..*. . . .
~~< {
,38 . . ‘$~~ ~: ,x~M % CM .x‘/7?9 ~7b%3
. . . . . . . . .. . . 738. . . . . . . . .,1:. . . . . *rg,. r”; , ._
. . . . . .7,8
. . . . . . . . . . . . .,, >...0761 Ohx ~
. . . . . . . . . . . . . . . . . . . . .~%=2rJi~-
8 1 1 I 1 ! 1 t 1 8 1 , , i % , 1 1 1 , 1 1 I , I
-’9’ ‘ 12- -’,.;83~. . . . . . . .
%3 “ -‘“””” -‘“ ‘“””” ‘“’””- ‘“”’”- -“””+!,, , . . . . . . . . . . . . . . . !,, . . . . . . . .. . . . . . )- ~~? ‘ “ --“’ ‘“--- IM18Z“ “. . . . . . 17/062_.. . _-151182; : .. ..> ~_.. .._ _-;:;:_ -:::.
t 1 +10”+o
t 1 1 , , 1 , 1 1 1 n 1 1 , 1 , , , I 1 s I , , t t , ,v ,
. . . . . . . . . . . . . . . . . .’O. . -. . . . .
.,. . ,.. . . ..! ,,, , . . .14o“ 120“ ““””- ‘“’””
,,, . ... , ... , . . . . . . . . . ... . ~
. . . . . . . . . . . . . . . . . . .
““:;- -;;;:-) 9 1 S 1 1 1 , 8 , , , 1 1 , 1 1 , 9 ,
]vla2~ ;00181?!~a~; : ;-_; ;;:.. . . . . . . . . . . . .,. . .,. , ,., .I(VI8Z :. ..- -,, - -. . ..-. . . . - L,. . ... , . . . . .,, , ,.. . . . . .
,.. . ... , . . . . . . . . . .- _’. . . . . . . . . . . . ... , . . . . -
. . . . ,.. . . . . . . . . . . . . . . . . . . . . . . . . . . “,, , . . . . -
,,,4 a t t 1 ,!1, II, ,. _l . . ..l I.. _I.. 111.1. 1 , ,1 1,1 , ‘e1 , 1 I , 1 s ,
c.,.,..,,,,,,1,,!,,,,,,,,,,ICI,,,,,,(,t--111,I1..............,,.........,.,..........,.....,,....................................!,,.....
...........,,.......,,....................
..!.....................................-....
1,#,1,t I11Ir,1b, I!1r1a, fI11t11,1Ir,{.............1-........-r...1-....,,...........
DTG
0818002090000Z0906002091200z091800Z1000OOZ1006OOZ1012OOZ1018OOZ11OOOOZ1106OOZ111200211180021200002120600212120021218002130000213060021312002131800214000021406002141200214180021500002150600Z15120021518002160000216060021612002161800217000021706002
LAT
13.ON13. ON13.2N12.5N12.8N13.ON13.ON12.ON11.5N11.52411.5N11.5N12.5N13.oN13.5N13. 8N14.ON14.4N14. 8N15.2N16.ON16.3N16.6N17.ON17.5N17.9N18.5N19. ON19.3N19.3N19.lN18.9N19.5N19.5N19. 3N
HURRICANE BERNICE08-17 JULY 1969
LONG
101. OW102.5W102. SW102. SW103. OWlo3.5\i105.5W107. OW107.5W108.2W107.5W108. OW108.5W109.5W11O.2W111. Ow112. OW113. Ow114*OW114*9W115. 7W116*6W117.5W118.5W120. OW121.lW122. 3W123.5w124.8W126. OW127.lw128.2W129.5W130.7W132.2W
24 HRERROR
300/33280/154295/134040/112060/178055/212320/114285/135240/123225/127190/122205/152105/110065/44060/58085/68190/42200/38220/40200/33100/31110/46115/65200/34110/25070/32005/106360/154010/60175/60115/72
48 HRERROR
200/162195/180125/210165/231110/238090/84075/72095/113120/58115/50115/78110/87120/90100/108005/123135/87045/41025/106010/226
24 HOUR FORECAST ERROR = 87.6 MILES
72 HRERROR
185/286
165/340
095/180
095/208
120/98
120/114
075/170
48 HOUR FORECAST ERROR = 123.4 MILES72 HOUR FORECAST ERROR = 199.4 MILES
AN- 14
I. DAT’A
A. STATISTICS
1. ?QU14BEll
2. NUMBER
08/04/1800z TO 08/09/1200Z
OF WARININGS ISSUED - 20OF WAIUiINGS \tITH HuRRIcANE INTENSITY – 6
3. DISTANCE TRAVELED DURING WARNING PERIOD - 875 MILES
B. CHARACTERISTICCS1. IsIINIIWJM2. MINIMUM3. ~4AXI~4U~f4. PLAXIMUM
II. DEVELOPMENT
OBSERVED SLP - UNKNOWNOBSERVED 700 NB HEIGHT - N(3TOESERVEDSURFACE WIND - 75 KT (EST.)RADIUS OF SURFACE CIRCULATION - 300 MILES
A. INITIAL 114PETUS - ITCZ
B. INITIAL SURFACE VORTEX1. 041800z2. SURFACE PRESSURE LESS THAN 1008 ME
c. TIME STORM REACHED HURRICAIJE IIJTENSIT’Y- 0518002
111. FINAL DISPOSITION
A. DISSIPATED OVER WATER
AN-15
>,-,
-0
.3’01
‘$&;
2--.?,
I,
I,
I,
I,
I,
,
..
..
..
..
..
..
.1o
?I
II
II
:o
_$o
l=
:*L,
.@
:~,30
‘\
h“
4.
.-+-.-N
t------
-..
..--..
.,$
,,
,,
r1
,,
J-.
..
..
.-...
..
..
..
N.“’
””’.
..
..
..
..
..
.
..
..
.a-
-.,.
..
..
..
..~
----
---------
II
,,
,,
,,
,,
1,
I1
,!
,t -
,,
,,
,,
,I
I
.“”,--,,
+!-’-+-~~~
‘~~~~~~~~~
:~.,.+ ....t .... .... .
.. ..,.. ....... ... ........
j“”-
‘“”””-‘“’””-
‘“”
”--
‘“”””
..
.*
..
..
..
..
0.
..
.m*
:=
GZ
-=.
::2.
”.
..
..
..
..
d-m
~::~..
..
.z
..
..
..
..
*-.
i=~~=~..-
....7....-
..
..
..
..
.1:=
::-~
.w
..
.*.
..
..
.-
2“”
.,.
.-R
I,
,,
IQ
,g:~-=;z
,,
!,
1,
(,
,,
,,
..
.“i?
===:””--“’””-
‘“”””-
““”-”-““’”-
II
1,,:,,,,:,,,,-::,,::,,,-
8“”.
..
~.
..
.-1
...
..
..
..
1’
1.
...-l“”
..
..
..
..
..
.
,,
I.
..“’++“-
‘“””-‘“’”’-
-’:””--“”””]I
AN-16
-1
.— , A . . .. . .—-.T--z-—n -— ;-—-7.—+.. ~,.$0, ~, . ..<.. ,,,. . . . K\& T t=-- ‘,0--- ~~- — - ‘.—cA~G:u ~ ~~G& “& . -“.,Wo,l$
I 1 1 , , I 1 t t , i I I- T——.—
. . :G’? 00%. . . . & _.. . . -r\ *x.;=”2.,, .
: i“?g:~~;~v:q~:g:~jcL&?’‘ ;~~;!$i.*z;’i:::2.. saw. . . . .,. . . . . . . m N*O o% w
. K“0. O!.;&.~.:~yop,B% o’o~ ~ o:“3?2 “,”6;“,
. .00 CHO
- ‘?/+y$.,x , ,,- ;“*. Gz 27P ,
p T
1‘:;:]’’J’” ~’:g$;~ :;;.:,$O’” ‘:
~ok 0;.,. !
TCs. . . . . . . . .,. . ~vc 0. M
.z,~&\” -& %. ;::
,.e ,:” p ,,,GGC
... , . . . , . . . . . . . . .5..,0 . I ‘?’o”m:,, ;, - .=D:r 0, ‘s %“ ‘w’ ,,W+- ?- w. .,0
%, 0+! $v5&
2W 054 “~’- <g{;,cyu - ,75y\$- ‘~~ 0<q 0J@’” g ,Ofx$.,, . . . . . ,.. . . . . 8 . ,ty,....,. 1 , 1 1 , , , ,+ o -1-+30”{ 1 , ,
,
i
r }30”+
cc f ):, kq
, ::UZ: : :“3? ;..&:%,t ,,,:<,,0 ‘dq.s~\
. . . . . . . . . . . . , 76?3, . HURRICANE DOREENOH. .%
... . . . . . ... . a-140”
. . . . T . . . .
120”. . . .
.,. . . . . . . . . . .,. . . . . .
24 HR FCST POSITS -::::. . . . . . . . ,.. . .,. . . . . .1 $ # 1 1 1 $ 1 1 1 , i 1 1 1 , 1 ) 1 I , ,
, , t ,1
. . . . . . . . . . . . . . . .fi~?,, 04. OS AUGUST 1969 _. .,,-
. . . . . . . , . . . . .,.
. . . . ,.. . . . . .
. . . . . . . . .,. . . . . ,.. . ,“,...0,.1 1 1 I , t 1I , , , , 1 I ,
.,. . . . . . . . . . . .
. . . . . . . . ,.. .
. . . , . . ... .,, . . . . . . . . . . .
I , 7, 1I I , , I 1 1 , ,r 1,
.LEGEND
. . . , . ~ Ow. .
& -- 24 Mm fMECA81 P081TS ““’. . . . . . .
-*— 6 M DCST TRACU POSITS . . .- . . ---- . . . .._ . . . Oj.m ~4,18. . . . . . . . . . . . . . .
T“ ““ ‘“i: ““: ““: H ‘“z :’”: ““, ,“”,
:“ 010” 10”
. . . . . . . . . . . . . . . . , . . . ... . . . . . . . .
. . . . . . . ,.,. . . . . .140”
. . . ..
. . . .120 “
.
.,. . . . .100“
. . . . . . . . . . . . .,. , . . . . .,. . . . . . . . . .
. . . . . . . . . . . . . .\
. . . . . . . . . . .,. , . . . . . .
, 1 1 1 , , I , , 1 I , t , , I , , 1 , , 1 1 , t , 1 , , 1 , 1 , , 1
. . .,, . . . . , . . . . . . . , . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . , . . . . , . . . . . .
... . . . . . . . . . . . . ,<. . . . . . . . . . . . . , . .
.,, , - -, . . . . . . . . . . . . .,. . . . . . . . . . . . . . . . .
,!, , --, ~
. . .
I $ , , , , .1111 1111 11.1 ! ,1 ,,, ! ,,, , 11 l,,, “c.
DTG
041800Z0500002050600205120020518002060000z060600206120020618002070000Z070600Z071200Z071800Z080000z080600Z081200Z081800Z090000209060020912002
LAT
17.ON17.ON17.ON17,7N18.2N18.7N18.8N19.lN20. 3N20.6N21. lN21.6N21.8N22.ON22.lN22.2N21.5N21.6N21.6N21.7X
HURRICANE DOREEN04-09 AUGUST 1969
24 HRLONG ERROR
107.5W108.5W109.5W11O.7W109.5W 240/13511O.OW 220/133111.5W 24u/144111. 9W 285/192113.4W 115/150114*1W 135/75115.OW 132/96115. 8W 125/158116.5W 340/36117.OW 315/52117.7W 323/74118.4W 330/96118. 8W 350/75119.7W 355/57120. 3VJ 355/60120.8W 330/74
48 HRERROR
215/235220/210222/238280/204115/230130/115118/117110/195335/192330~195335/226335/250
72 HRERROI?
230/270
290/355
080/120
075/260
24 HOUR FORECAST ERROR = 100.4 lsIILES48 HOUR FORECAST ERROR = 200.6 MILES72 HOUR FORECAST ERROR = 251.3 MILES
AN- 18
HURRICANE GLENDA -
I. DATA
A. STATISTICS1. NUMBER2. NUMBER
09/08/OOOOZ to 09/12/0600Z
OF WARNIi~GS ISSUED - 18OF WARNINGS WITH HURRICANE lNTENSITy 1
3. DISTANCE TRAVELED DURING WARNING PERIOD - 1248 MILES
B. CHARACTERISTICS1. MINI lflUM2. MINIi\’IUM3. NAXIMUI-I4. MAXIMUM
II. DEVELOPMENT
OBSERVED SEA LEVEL PRESSURZ - UNKNOWNOBSERVED 700 MB HEIGHT - UIJKNOh?tJ
SU~’AC~ ~IND - 65 KTIUIDIUS OF SURFACE CIRCULATION - 125 MILES
A. INITIAL IMPETUS - ITCZ
B. INITIAL SURFACE VORTEX
1. 080000z2. SURFACE PRESSURE LESS THAN 1008 MB
III. FINAL DISPOSITION
A. DISSIPATED OVER WATER
AN-19
,
~-,!II,[rI1,1Iz,I,II111111I11II1-g.,.
01-..........................,
......,..,.......‘i NoIss3uJioivoidou ...,...............
L..........._,.,,-.....-_,,,.--,,,,-_,,..--,ULDISlV31dOlilMO3NVOlUlinH
,0334s,1I,11I1IIr1I1,1,11
....,,......,..,,..........S3X14UvovuONV1
.....,......,,............MO31111111VS‘1JVM3UIV.Oo1.Ozl
,
1(,!....
L. .... ---- .,., *v’”,. *bl
w::)4>:~~~~~~ i:~~........ .20018.0-.::::--::::-.::::.-::::-.:
kSllSOd)lWll1S38tlH9~“
....,..
.01mm
sol............
I1.““”e“’””“’””““”” ....“’l:::-i:::-: Oomo-------....--...
k&L4&+i’7’- ‘‘‘‘‘‘‘-i-..L.....
.,.,....,..,
,11t,I1,111t,I
.......
...,...............
.......,,.
II,II,II1[1I,
.........
.......
............
.....
,,,,,11,!I1It1
.......,,......r
.Ovl...........
............
1,,I1I,1,,1t.ocb--l--0+
.,.
.........
........
.,.......
.....,......
,!,,,I,,IIII,
...........
,,1->,...,,.+.,,.*
:::;.,.,
..
..
..
..
..
..
..
:..
..
..
..
..
..
..
it
1I
I,
I,
1,
,t
It
,.
..
..
..
..
..
..
.,,
..
..
..
..
..
..
.,..
..
..
..
..
..
+
..
..
..
..
..
..
..
..
.b~
..
..
.
..
..
..
..
..
..
.L
..
..
..
..
..
..
..
..
,,
,,
I,
II
,,
,
.+.
...+
1......T
..
..
..
..
..
..
..
..
.
~:.
,
.::::-
,,
-::.’:-,
,-::::
.:w-
-!!!.
..
..
..
..
..
..
..
..
..
..
..
.’..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
.
-t,
I1
,,
,,
,,
,!
,,
1,
,,
,,
,.
..
..
..
..
..
..
..
..
..
.“i
..
..
..
..
..
..
..
..
..
.-1
$~
..
..
..,+
..
..
..
..
..
..-
..
..
..
..
..
..
..
..
..
..
.-
+#
,:~
-.+-+$~
1k
,a
I1
11
1,
,,
,.
..
.,“
“
i..-..:
-..
..-:..
..
..
..
..
..
1..
.
...1 ....
..
....,...,.
.I
,$
..
..
..
..
..
.,..
.+
-t-l-&.
..
..
..
..
..
..
1~
..
..
t..
..
HURRICANE GLENDA08-12 SEPTEMBER 1969
DTG
080000Z080600Z081200Z081800Z090000Z090600Z091200Z091800Z1000OOZ1006OOZ1012OOZ
*lo1800z
11OOOOZ1106OOZ111200Z111800Z120000Z120600Z
LAT
14. 8N15.4N15.7N16.4N17.ON17.3N17.7N2001N21.ON22.4N23.5N22.6N23.5N24.4N25.5N25.7N25.3N26.ON
LONG
100.OW101. 5W102 ● lw103.5Wlo5.ow105.7W106.5W107. 7W108.4W109.1W109.4W111.8W112.7W113*7W114*OW115*7W116.6W117*5W
24 HRERROR
110/185110/137110/145150/165170/165175/225185/258325/45055/160055/270050/190195/78350/130DISSIPATED
48 HRERROR
150/258140/350150/372155/230150/258160/280165/360360/68055/190
24 HOUR FORECAST ERROR = 165.6 MILES48 HOUR FORECAST ERROR = 262.9 MILES72 HOUR FORECAST ERROR = 451.7 MILES
72 HRERROR
130/504
135/516
140/335
* RELOCATED
AN-22
HURRICANE JENNIFER
I. DATA
A. STATISTICS1. NUMBER2. lJUMBER
- 11/08/18002 TO 11/12/03002
OF WARNINGS ISSUED - 15OF WARNINGS WITH HURRICANE INTENSITY - 8
3. DISTANCE TRAVELED DURING WAPNING PERIOD-- 754 NM
B. CHARACTERISTICS1. MINIMUM OBSERVED SEA LEVEL PRESSURE - N/A2. MINIMUM OBSERVED 700 MB HEIGHT - N/A3. MAXIMUM SURFACE WIND - 70 KTS4. MAXIMUM RADIUS OF SURFACE CIRCULATION - 65 NM
II. DEVELOPMENT
A. INITIAL IMPETUS - ITCZ
B. INITIAL SURFACE VORTEX1. 08/180022. SURFACE PRESSURE LESS THAN 1008 MB
c. TIME STORM REACHED HURRICANE INTENSITY - 09/18002
III. FINAL DISPOSITION
A. DISSIPATED OVER LAND.
AN-23
Ii UIWCAIVE JE/VfV/FER ~~%-Ji” .
BEST TRACK :$ ~
o MCI
08-12 OCTOBER /969 &-
,?..,4 #;; “10”””**00?
+ I # 1 1 t I I 1 1 , $ I , t
, . . . . . I -0 --- .-. -“~
. . . . . . . . . . . . . . ‘w ‘u’ I\= %:3!-T;:“ 7 ‘q :,”~i=flj :$ ‘%’’”,:.-w , ,0, - c,% , ,*’~;
,. . . . . . . . . . . . . . . ?GUam. . . . . . . . . . . . . . ,,. .. . ,.. , ... , ... . . . . .. . ,,. . ,., , .,, . . . . .i-1--’t’--t--t3o”l, I , , , , , , 1r , r r +30”{
t
1 I 1 1 1 I I t 1 1 I 8 1 t 1 I 1 ,
a-
i 1 , , r , , ,
., . . . . . . . . . . . . . . . .76?s, . .
. . . . . . ,,,o#’. ..,, ,.-. . . . . . . . ... . . . . . Wm. . . .
140”. . . . ,,0
12o“.. . . ,,. . ,.!, . . . .:, . . . .
., ... , .,. . ,.. . .,. . .,. .
. . . . . . . . . . . . . . . . . . . . .
., ... . . . . . ... . . . . . .,. ,
. . . ..-. . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
, , , , , , ,i , I , , I I 1 , , , I , , , , , , ,‘ “d. ~A: --’<%’”f
,, . . . . . . . . ,.. . . . . . . . . .
. . ,.. . . . . . . . . . . . . . . . . .
. . ..!. . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
II , , t , I I , 1 I I I I I I 1 I I 1 I I I I
,
. . . . . . ... . ,., , ,., , - .-, ,, ,
. . . . . . . . . . . . . . . . . .,. .
. . . . . . .,, . . . . . ,.. . . . . .
. .- ‘ LEGEND -““””- ‘“””’- ““””- ‘“’”’-
1 , , }10”+ , r , , , 9 r , , 1 ~lo”! ,
R BEST”TliACK PQSH$ “ “ ‘ “ “ . ~ . -. . . . .
1
J-
I“ “08- [02 ““””’””’- ““””-
Ot? ::: :120“:::: :::: ::::. _::::’~ y::::- .: :::;. . -1-,. . . . . .,. . .,. . . . . . . . . . . . . , ... , -
, 1 I 1 1 1 I 1 , 1 1 0 1 1I t 1 I 1 , 1 I 1 I , 1 , ,,--— —h Uf@[email protected] -gq f.~dp!q IL.$?QRM -.....- -, .,,- -,, ,.- _, . ..- . ...,.- -. . ..-. . ..!,
. ... , ,- -.. . . . . . . . . . . . . . . ,.. . ,,, , . . . . . . . . ... . -,. . . . . . . . . . . . . . . . . . ,.. . ,. . . . . . . . . . . . . . . . . . . . . -. . . . . . ,.. . . . . . . . . . . . . . . ... . --,. . . . ,., . . . . . . . . .-
,. ,!, , !,, , ,,, , ,,, , 1111 ,18 ... ‘a
.,,....... .........................,,.e..o .......
.........................,,..........
.,..
.....................,..................
.........,........!.....................
I,1r,,,II1rI1r1,r1,1,I11r,I1I,1rr11r
............................
Js3fl&h9’=m-H-‘“ ...............!.......001“”
.....0?1 ........................,..,kioititPi-b:“::1:
.........,!,,(I#,;601;?8.//%?o,;::;;::.:::00,:::::;;;;::;:;;;*O, “;;
●
.,...,...............................................zMO”“:‘“””-‘“”””-““””-““”-‘“”’”-“ ....................
,3;;:::’;::::::::::::::
““”-“’””-‘“””’-‘“’””-‘“””””-“ ““”--“”’”--“”””--“”’”--’”””--’
::::::::::::::::::::::::::::::
...-_....--,------....--...,--.Inl/il:::--::::-_::::--::::_-::::_-:
,
“;‘“:’“;;‘“;“;’“
...................
.........,.,........
‘““.OZ,“”””“’””““””‘“””.Op,“-“”--‘“”--’”’”-‘“”””--“”””’
..1s??. .1 L.-‘“’””--“”””--“”””--“”’”.
+.0s+*OS*o+
696!L13HOH0ZI-QO->%;~,~----.:..--::::--:!..::.
fSflsodfsv33u03aflo~*Zi?-.”%$:’1>$” ‘-““””-‘“””’-“’’”--““””-‘“oq%ol%-..----....--,...,..,,
f~wM3dlNN3r3Nv3JHHfiH$%40#%RJ~N g.,.-....--------,...-.
‘&:~;&;it‘T~~1,,,,,I,,‘~.:ix:?gawy;~..--
1.,..-!!I
-------.--.,, m
!‘-x”fi~::q_.:,-y=‘7:%--2-!---:.!8,1J+:::_;‘p:!’A~.ij&.,?gg.._-,,.,-r..----....-~,
m
DTG
081800Z090000Z090600z091200z091800z1000OOZ1006OOZ1012OOZ1018OOZ11OOOOZ1106OOZ111200Z111800Z1200002
LAT
14.ON14.2N14.8N15.2N17*ON18.lN19.2N19*5N19.3N20.ON20.3N20.9N22.7N24.ON
HURRICANE JENNIFER08-12 NOVEMBER 1969
LONG
102.5W102.7w104.6w106.2W106.9W107. 3W107.8w107.8W108.6W108.8W109. OW109.1W107. OW106.5W
24 HRERROR
170/132190/175200/246220/270320/115330/187360/213020/138
24 HOUR FORECAST ERROR = 18548 HOUR FORECAST ERROR = 353
48 HRERROR
220/252240/330240/393240/437
MILESMILES
72 HRERROR
240/509
72 HOUR FORECAST ERROR = 509 MILES
AN-26
APPENDIX A
ABBREVIATIONS AND DEFINITIONS
1. Words and phrases that appear frequently in this report areabbreviated as follows:
ANALAPTATSCINCPACCINCPACAFCINCPACFLTCIRCCPADEGDTGESSA
FNWC
FWCIJTWC
ITCZ or ITCJHWCKT (S)MAXMB(s)MINMI or N.M.MODNEDNNESC
POSIT(S)PROGRECONSLPT.T. DoT. S.Vwl54WRS
2. The following items
AnalysisAutomatic Picture Transmission
Applications Technology Satellite
Commander h Chief, PacificCommander in Chief, Pacific Air ForceCommander in Chief, Pacific FleetCirculationClosest Point of ApproachDegree(s)Date-Time GroupEnvironmental Science ServicesAdministrationFleet Numerical Weather Central,Monterey, CaliforniaFleet Weather Central/Joint TyphoonWarning Center, GuamIntertropical Convergence ZoneJoint Hurricane Warning, Center, HawaiiKnot (s)MaximumMillibar(s)MinimumNautical MilesModificationNaval Environmental Data NetworkNational Environmental SatelliteCenter, Suitland, MarylandPosition(s)PrognosisReconnaissanceSea Level PressureTyphoonTropical DepressionTropical StormAirborne Early Warning Squadron ONE54th Weather Reconnaissance Squadron
define and clarify certain words andphrases that appear in the Eye Fix Summaries in Chapter V.Several definitions in this section have special meanings withregard to the machine prepared Eye Fix Summaries and may not
necessarily have the same meaning as used elsewhere in thereport.
a. FIX IJO. - the chronological order of fixes for eachindividual tropical cyclone.
AP-1
b. TIME - the date-time of the fix.
c. POSIT - the latitude and longitude
d. UNIT - METHOD - ACCY:
(1) UNIT - the unit that made thereconnaissance squadron; 54-54WRS, VW-VW1.
of the fix.
fix if made by a
(2) METHOD - the method used to make the fix; P -penetration, R - radar (these two refer to fixes by reconnais-sance squadrons) ,SLTIS - satellite
(3) ACCYgational accuracy
e. FLT LVL -meters above mean
LND RDR - land radar, SHP RDR - ship radar,cloud picture location.
- center determination and estimated navi-of the fix (in nautical miles) .
altitude of aircraft at time of fix in wholesea level or given as a constant pressure
surface; or, stage (STG) of development for a satellite location.
f. FLT LVL WND - maximum observed flight level wind speedin knots; or, diameter (DIA) in whole degrees of latitude fora satellite location.
9= OBS SFC WND - maximum observed surface wind speed inknots; or, number of bands (BNDS) for a satellite location.
h. OBS MIN SLP - minimum observed sea level pressure inwhole millibars (reported on penetration fixes only).
i. ~41N 7oo MB HGT - minimum observed 700 mb level heightin whole meters.
]0 FLT LVL TT/TD - flight level temperature (TT) anddewpoint (TD) at fix location.
k. EYE FORM - description of cloud eye; CIRC - circular,ELIP - elliptical.
1. ORIENTATION - direction of orientation of an ellipticaleye to an eight point compass.
m. EYE DIA - eye diameter or major/minor axes of an ellip-tical eye, in N. M.
n. THKNS WALL CLOUD - thickness of wall cloud in N. M. ifobserved. F. B. (feeder bands) or N. F. B. (no feeder bands)may be entered if
3. The followingthis report:
a. VORTICES:
wall cloud thickness not observed.
definitions are given to clarify usage in
AP-2
(1) Cold vortex - a closed cyclonic circulation identi-
fied as having originated as a cold core system removed fromthe ITCZ or any easterly wave.
(2) Embedded vortex - a closed cyclonic circulationalong an easterly wave and separated from the ITCZ.
(3) Junction vortex - a closed cyclonic circulationat the junction of an easterly wave and the ITCZ.
b. RECONNAISSANCE FLIGHTS:
(1) SYnoptic track - a set reconnaissance pattern be-tween specified coordinates scheduled to gather and reportMeteorological data.
(2) Investigative flight - weather reconnaissance ofan area containing a suspected circulation.
(3) Fix mission - aircraft reconnaissance scheduledto fix the center position of and gather peripheral data abouta known tropical cyclone.
c. FIX - the determination of the position of a tropicalcyclone at a precise time, generally by reconnaissance aircraftpenetration of the center or by airborne, land, or ship radar.In the case of a reconnaissance aircraft penetration the actualfix may be based on any of the following: visual observationof the cloud pattern and sea surface, radar, surface pressure,surface or flight level winds, constant pressure height ortemperature.
d. The term “tropical cyclone” has two definitions as usedherein depending on usage:
(1) “Tropical cyclone” may be used to describe a sus-pect cyclonic circulation which appears to be capable of intensi-fication.
sense e.:?!“Tropical cyclone” may be used in the general
“Typhoon Agnes was the most intense tropical cycloneof 1968”, or “tropical cyclones most frequently develop duringAugust and September”.
e. TROPICAL DEPRESSION (T.D.) - as used by JTWC this is anumbered tropical cyclone in which the maximum sustained surfacewind speed is 33 knots or less and whose winds are expected toincrease to 34 knots or more within 48 hours.
f. TROPICAL STORM (T.S.) - a named tropical cyclone inwhich the maximum sustained surface wind speed is greater than33 knots but less than 64 knots.
9* TYPHOON/HURRICANE - a named tropical cyclone in whichthe maximum sustained surface wind speeds are 64 knots or greater.West of 180 degrees longitude these are called typhoons, east of
AP- 3
180 degrees they are called hurricanes. All references to ty-phoons apply equally to hurricanes.
h. Recurva~ure - that point at which a tropical cycloneceases movement to the west of north and commences moving eastof north.
AP-4
