NOAA Technical Memorandum NWS NHC 25

A TROPICAL CYCLONE DATA TAPE FOR THE EASTERN AND CENTRAL NORTH PACIFIC

BASINS, 1949-1983: CONTENTS, LIMITATIONS, AND USES

Mary A. S. Davis, GaiNHC, Miami, Florida

M. Brown, and Preston W. Leftwich, Jr.

National Hurricane CenterMiami, FloridaSeptember 1984

UNITED STATES / National Oceanic and / National Weather

DEPARTMENT OF COMMERCE Atmospheric Administrati.. Service

Maltolm Baldrige. Secretary John V Byrne. Administrator Richard E. Hallgren. Director

CONTENTS

1ABSTRACT..

11. INTRODUCTION.

1

2.

DATA SOURCES ",.,

43. CENTRAL NORTH PACIFIC STORMS

44. DATA FORMATS

65. WIND SPEEDS

9CENTRAL PRESSURES6.

9APPLICATIONS OF THE DATA7.SUMMARY. 118.

ACKNOWLEDGMENTS.

11

REFERENCE S 12

APPENDIX I, TERMINOLOGY 14

APPENDIX II, A SAMPLE FORTRAN PROGRAM TO READ AND WRITE THE DATA.. 15

iii

A TROPICAL CYCLONE DATABASINS, 1949-1983:

TAPE FOR THE EASTERN AND CENTRALCONTENTS, LIMITATIONS AND USES

NORTH PACIFIC

Mary A. S. Davis, Gail M. Brown, and Preston W. Leftwich, Jr.NOAA, NWS, National Hurricane Center

Coral Gables, Florida 33146

ABSTRACT. A collection of data concerning tropicalcyclones in the Eastern and Central North PacificOceans has been compiled at the National HurricaneCenter. This data set consists of dates, tracks,and maximum sustained wind speeds of tropicalcyclones occurring from 1949 to 1983. Surfacepressures, when available, are also included.Sources, characteristics, and format of these dataare discussed.

1.

INTRODUCTION

The Research and Development Unit at the National Hurricane Center(NHC), Coral Gables, Florida archives the Eastern and Central NorthPacific tropical cyclones onto magnetic tape for computer processing.For the 35-year period, 1949 through 1983, 432 tropical cyclones aredocumented. Tracks of these storms are shown in Figure 1. TheEastern North Pacific (ENP) extends from the coasts of the UnitedStates, Mexico, and Central America westward to 1400 west longitudeand from approximately 50 to 350 north latitude. The Central NorthPacific (CNP) is an extension of this area to 1800 west longitude.This report describes the content, limitations, and uses of the data.

This report is an update of an earlier NOAA Technical Memorandum,NWS NHC 16, written by Gail M. Brown and Preston W. Leftwich, Jr. inAugust 1982. Many changes have been made to the data. The data for-mat has been completely revised to resemble that for the AtlanticTropical Cyclone Basin (Jarvinen, Neumann, and Davis, 1984).

2.

DATA SOURCES

An earlier study by Crutcher and Quayle (1974) indicated the lackof long-term records of tropical cyclones in the North Pacific Oceaneast of l80oW. The period of then available data (1949-1971) was byfar the shortest period of record for any of the six recognized tropi-cal cyclone basins around the world. Before the advent of meteorolo-gical satellites, which came into daily opertaional use in 1965, dataon ENP and CNP tropical cyclones were limited to chance encounters ofships at sea, rare passages of storms over land stations, and infre-

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quent aerial reconnaissence. The greatest number of reports wasrecieved from ships at sea. Generally, these ships were travelling inthe periphery of a storm's circulation, so the distance to the stormcenter was unknown. As warnings became better, even fewer shipsencountered storms. Aerial reconnaissance was confined to periodswhen a storm was threatening land. Undoubtedly, some storms werenever detected.

The first location by satellite of a storm in the ENP was made byTIROS III on July 19, 1961 (Mull, 1962). Subsequent operationalcoverage supplemented wind data and greatly increased the capabilityfor detection and tracking of storms. The importance of satellitesfor detecting tropical cyclones in the ENP and GNP is supported by theincrease in the mean number of observed tropical cyclones per yearfrom 8.6 for 1949-64 to 14.8 for 1965-83.

The original impetus for compilation of these storm tracks werethe implementation of several techniques for statistical prediction oftropical cyclone motion in the Eastern North Pacific Ocean. Amongthese are EPCLPR and EPANLG (Neumann and Leftwich, 1977) and EPHC77(Leftwich and Neumann, 1977). Development of the models requiredtracks of past cyclones as a statistical base for the predictionequations.

Under sponsorship of the United States Navy in 1971, theNational Climatic Center revised and reissued its data as TropicalCyclone Data Card Deck 993. These and additional storm tracks for theperiod 1949-75 were acquired from the U.S. Navy located in Monterey,California. Initially, storm positions were given at 12-hour inter-vals. Interpolations of these positions to 6-hour intervals were madeby use of a scheme devised by Akima (1970), with some subjective modi-fications. Since 1976, storm positions, at 6-hourly intervals, havebeen obtained directly from the Eastren Pacific Hurricane Center(EPHC) located in Redwood City, California.

Criteria for constructing the tracks were based on the concept ofthe "best-track". Through a process of careful post-analysis of allavailable sources of information, including aircraft reconnaissancefixes, ship reports, advisories issued by EPHC, satellite data, andoriginal operational tracks, these storm positions were subjectivelysmoothed. Resultant 6-hourly positions provided a reasonable ren-dition of actual continuous storm tracks.

Smoothing is performed for two reasons. First, small-scaleoscillatory (trochoidal) motions of a storm's center are transitory innature and not representative of the more conservative motion of theentire storm system. Recent evidence of such motion based onsatellite imagery of Hurricane Belle (1976), in the Atlantic Ocean, isdocumented by Lawrence and Mayfield (1977). Actual errors in posi-tioning tropical cyclones are a second consideration (Neumann, 1975;Sheets and Grieman, 1975). All data sources are subject to thisproblem whether it results from poor positioning of a satellite pic-ture grid or navigational errors experienced by ships and aircraft.

3

In all cases, therefore, 6-hourly positions representmotion, rather than precise locations of the eye. large-scale

Where possible, tracks have been extended to include land posi-tions once a storm crossed a coastline. Rapid dissipation along themountainous west caost of the North American continent usually occurs,making storms difficult to track. Therefore extrapolations of earlierstorm motions were performed with the aid of synoptic weather maps andsatellite pictures.

In 1980, a thorough review of the storm tracks was made by ArnoldCourt under contract (NA-79WD-C-00006) from the National WeatherService. His work concentrated on extensions of tracks inland andresulted in additions and/or modifications to 81 storm tracks in theoriginal data set. A final review, including checks for consistencyas well as errors, was made once the data had been placed in a com-puter card deck.

3. CENTRAL NORTH PACIFIC STORMS

The majority of information concerning storms in the CNP wasextracted from Shaw (1981). Although Shaw gathered information con-cerning storms as far back as 1832, only those beginning in 1949 orlater are included in this data set. Systems which failed to attainat least tropical storm strength east of 1800 west longitude wereexcluded.

Those that attained at least minimum tropical stormstrength and continued west of 1800 were included through their dissi-pation stages. Additional information was obtained from a few edi-tions of the Annual Typhoon Report of the Joint Typhoon Warning Center(JTWC) in Guam. Several CNP storms for which only one position wasavailable were excluded because data for at least 12 hours arerequired in the development of statistical prediction models.

4. DATA FORMATS

All storms are listed in chronological order according to theirfirst recorded day. Names are in alphabetical sequence except whereCNP storms appear since they follow a separate naming system. Thegeneral format established for these data is also documented byJarvinen, Neumann, and Davis (1984) for Atlantic Ocean tropicalcyclone data. New data are added at the end of each tropical cycloneseason.

The master card deck used to generate the original computer tapeconsists of three types of cards: title, data, and classification.For each storm there is one title card which contains all identifyinginformation. First is the sequence number for easy cataloging of thedata.

The month, day (first recorded day of the storm), and year

4

follow in that order. The next three numbers refer to the number ofdays the storm existed (M), the storm number for that year, and thecumulative storm number (SNBR), where the first storm in 1949 is 1 andthe last storm in 1983 is 432. Next follows the storm name. Beforethe naming of tropical cyclones in the ENP in 1960, a "NOT NAMED"message fills this space. Note that all CNP storms are named, eventhose as early as 1950. The final integer value is a land crossingindex (XING). This is either zero (0), indicating that the storm didnot affect land, or one (1), indicating that it did. A storm isdefined to have affected land if it came within approximately 50nautical miles or crossed the coastline of the United States, Mexico,Central America, or the Hawaiian Islands.

The title card is followed by one or more data cards, one for eachday of the storm's existence. Each contains four sets of valuescorresponding to the times 0000, 0600, 1200, and 1800 GMT. Includedin each set are the storm position (latitude and longitude, degrees oflongitude west of 180° are added to 180°, e.g., 1600E = 200° W, bothto the nearest tenth of a degree), maximum sustained wind speed, andthe central pressure.

The classification card indicates the maximum intensity of thestorm. This index is either TS (tropical storm) or HR (hurricane).

Tables 1 through 3 indicate the exact location of each parameteron the three types of cards. Computer cards for Liza, 1976, and anunnamed storm, 1951, are illustrated in Figure 2. Cards such as thesewere transferred to tape in card image, 80-byte records. A shortFORTRAN program which may be used to access data from the magnetictape is given in Appendix II.

Table 1. Title Card -Format and Contents

Computer Card Columns Contents

17

101320233136

Card sequence numberMonthDay (first recorded day of the storm)YearValue of M (M = number of days storm existed)Storm number for that yearCumulative storm number (1 begins 1949)Storm nameLand crossing index

5

-5258

111621243446

Table 2. Storm Data Card -Format and Contents

Computer Card Columns Contents

1 -57 -8

10 -1113 -15

Card sequence numberMonthDayLatitude at OOOOZ

16 -1921 -2325 -2830 -3233 -3638 -4042 -4547 -4950 -5355 -5759 -6264 -6667 -7072 -7476 -79

Longitude at OOOOZWind speed at OOOOZCentral pressure at OOOOZLatitude at 0600ZLongitude at 0600ZWind speed at 0600zCentral pressure at 0600ZLatitude at 1200ZLongitude at 1200ZWind speed at 1200ZCentral pressure at 1200ZLatitude at 1800ZLongitude at 1800ZWind speed at 1800ZCentral pressure at 1800Z

Table 3. Classification Card -Format and Contents

Computer Card Columns Contents

1 -5

7 -8

Card sequence numberMaximum strength of storm

()

* * **2631094 110 X2751092 070 **2141087 120 0946*2261089 120 0971**1901080 110 *1931081 120 0971**1751083 085 *1801081 090 **1561087 045 *1591087 055 **14101090 030 *1441090 035 ** *1301070 025 *

34090 HR34084 10/02X2881086 035 *34082 10/01*2381092 120 *2501094 11534080 09/30*1981083 120 *2041085 12034070 09/29*1851079 100 *1881079 10534060 09/28*1631086 065 *1691085 08034050 09/27*1481089 040 *1521088 04534040 09/26*1311080 025 *1361087 03034030 09/25* *34020 09/25/1976 M= 8 13 SNBR= 316 LIZA

XING=!

0000000001111111111222222222233333333334444444444555555555566666666667777777777812345678901234567890123456789012345678901234567890123456789012345678901234567890

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FORTRAN STATEMENT

0 0 0 0 0 0 0 0 0 0 0 000 0 0 0 0 0 0 0 0 0 0 0 ooToo-o 0000 0 0'0'0 00 0 0 0 0 0 0 ODD 0 0 0 0 0 0 0 0 0 0 0 0 01112 3 4 8 9 10 11 12 13 14 15 16 17 18 1920 21 22 23 24 25 2') 27 2B 29:1) 31 32 33 34 35 ~ 37 3B 39 40 41 42 43 44 45 46 47 4B 49 50 51 5253 54 55 56 57 58 59 60 61 62 63 64 65 66 67 6B 69 70 71 72

111111 111111111111111111111111111111111111111111111111111111111111111111111

2;2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 212 2 2 2 2 2 2 2

313 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

14:44 4444444444444444444444444444444444444444444444444444444444444444444444444

15155 5 5 5 5 5 5 5 5 5 5 5 5 555 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 555 5 5 5 5 5 5 5 5 5

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 0 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 1 7

8 8 8 8 8 8 8 8 8 8 8 8 888 8 888 888 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 888 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8~8 8 8 8 8 8 8 8

1999999999.999ge99999999999999!!9999999~999S9999999999999999,12 3 4 I 1111121314151117 II II a 21 22 23 H 25 2S 27 a a ~ 31 ~ 3) 34 35 ~ 37. ~. 4142 43 44.46 47 4B 4B 50 51 52 53 54 55 56 57..81112 a C4 ~ E 67 A ~ 70 71 72 37475 76 n 71 79 8

...888157 -~-- -IT310 TS-. ~11300 09/15*2171094 *2171102 *2191109 * *11290 09/14*2181078 *2191081 *2191084 *2181088 *11280 09/13*2091067 *2121069 *2141072 *2161075 *11270 09/12*1861057 *1921057 *1981058 *2041062 *11260 09/11* * *1711056 *1791056 *11250 09/11/1951 M= 5 7 SNBR= 20 NOT NAMED XING=O

0000000001111111111222222222233333333334444444444555555555566666666667777777777812345678901234567890123456789012345678901234567890123456789012345678901234567890

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STATEMENTIC

FORTRAN IDENTIFICATION

0000000-08 9 18 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 13 29 :II 31 ~ 33 34 35 ~ 37 .J9 40 41 42 43 44 4S 46 47 48 G 59 51 52 53 54 55 56 57 58 59 60 61 62 G3 64 65 66 67 68 68 ro 71 n

11111111111111111111111111111111111111111111111111111111111111111 11 1

7 7 7 7 7 7 7 7 1 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 1 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 1 7 7 7 ~ "1 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8

19999 9 9 9 9 9 9 9 9 9 9 9 9 9999999999999999999999999999999999199999999I 2 3 4 516 11 ..it" 12 13 1415 16 11 18 192D 21 22 2124 25 76 21 28 21 !) JI 32 33 34 ~ S 3J » :;9 40 41 4243 44.. .4J 48 .~ 51 5% 53 54 55 S 51 !I ~ 80 8112 53 ..15 II"' 18 n 10 11 12m 14 73 111118 19 ~

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Figure 2. Computer cards for a) Hurricane Liza and b) unnamed storm, 1951.

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4:44 4 4 4 4 4 4 4 4 4 4 44 4 4 4 4 \ 4 4 '

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11111

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3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

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6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6&

5. WIND SPEED

Wind speeds were assigned to corresponding storm positions. Windvalues throughout this data set are subjective estimates of the maxi-mum surface wind which ordinarily occurs at the eye wall. Thesevalues are specified in knots, rounded to the nearest 5-knot value.For example, 67 knots became 65 knots, while 68 knots became 70 knots.By definition, these winds represent l-minute averages rather thanpeak gusts; however, because of the subjective nature of estimatesbased on fragmented information available to forecasters, this defini-tion implies a precision which never exists. Discussions concerningrelationships of gusts to average winds in tropical cyclones may befound in papers by Dunn and Miller (1964), pp. 61-67; padya (1975);and Atkinson and Holliday (1977).

For many years ship observations were the primary source of winddata over the ocean. Mariners favor state-of-the-sea determinationvia the Beaufort scale (U.S. Navy Oceanographic Office, 1966) becauseit is a one-step method. However, over the past 30 years some shipshave been equipped with anemometers. A study by Shinners (1963) foundthat anemometer versus state-of-the-sea measured winds were (1) lowerup to about 20 knots, (2) approximately the same from 20 to 30 knots,and (3) greater above 30 knots. In essence, state-of-the-sea measuredwinds are underestimates of the actual wind at higher speeds.

The first wind data from aircraft reconnaissance in the ENP wereobtained in 1956. Although aircraft reconnaissance measures theflight-level winds anywhere from 500 to 10,000 feet, the surface windsare subjective estimates based upon observation of the sea stateand/or tables relating flight-level winds to surface winds.

Development of techniques to determine wind speed from the shapeof the cloud field, as depicted in satellite pictures, by Dvorak (1973and 1975), and Hebert and Poteat (1975), has tremendously increasedcredibility of wind estimates in recent years. Satellite imagery isnow the major source of data in all tropical cyclone basins.

Classifications (TS or HR) of storms prior to 1954 are fromNational Climatic Center data files. The quantity of wind speed datagreatly increased in 1965 with documentation of intensity at variousstages of the tracks by Mariners Weather Log (~) and later byMonthly Weather Review (~). As a result, it was possible todistinguish depression stages of both formative and dissipativeperiods. A small quantity of wind speeds was found in theClimatological National Data Summary, but most were estimated from ~Land ~ or taken from official advisories issued by the EPHC. Becauseof the extremely subjective nature of wind speed estimates, the useris cautionsd not to make overly precise interpretations of thesevalues.

8

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Figure 3. Annual frequency from 1949 to 1983 of 432 Eastern and Central

Figure 4. Plotted tracks of tropical cyclones listed in Table 4.

252~2322212019181716151~13121110

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North Pacific tropical cyclones that reached tropical stormstrength (open bar) of which there were 209 that reachedhurricane strength (closed bar).

Table 4. Storms passing within 200 nmi of Honolulu, Hawaii, 1949-1983

8/12/19509/01/195711/29/19578/07/19588/02/19599/12/19638/11/19728/05/19769/14/19817/07/827/26/8211/19/837/23/8310/08/83

123456789

1011121314

HIKI 23.0N 156.6WDELLA 19.0N 159.9WNINA 20.6N 161.0WNOT NAMED 20.3N 158.0WDOT 21.0N 159.0WIRAH 21.1N 157.8WDIANA 20.7N 154.8WGWEN 23.1N 157.5WJOVA 22.5N 157.0WDANIEL 20.4N 156.0WGILMA 18.4N 158.4WIWA 23.3N 158.4WGIL 22.2N 157.9WRAYMOND 21.3N 157.5W

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TX

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TDDDDHTD

Intensity Index for Table 4 is as follows:

D -Tropical DepressionH -HurricaneT -Tropical StormX -Extratropical Cyclone

For further information definitions in Appendix

I.

see

8.

SUMMARY

Development of statistically-based tropical cyclone predictionmodels requires historical data including dates, tracks, maximumsustained wind speeds, and central pressures. Such information fortropical cyclones in the Eastern and Central North Pacific Oceanduring the period 1949-1983 has been compiled at the NationalHurricane Center. Pre-1965 data are extremely limited; however, theadvent of operational satellite coverage in 1965 greatly increasedobservational capabilities. Compiled data have been stored viaelectronic computer. Data from succeeding tropical cyclone seasonswill be added to the current data set.

11

1603020807182017202201

240323

ACKNOWLEDGMENTS

The author wishes to acknowledge that this is an update to theprevious Technical Memorandum NWS NHC 16 "A Compilation of Eastern andCentral North Pacific Tropical Cyclone Data" by Gail M. Brown andPreston W. Leftwich, Jr. They compiled all the original data onto theoriginal computer file. However, recently many changes have been madeto the file as indicated herein.

12

REFERENCES

Akima, H., 1970: A new method of interpolation and smooth curvefitting based on local procedures. ~nal of ~he Association forComputing Machinery, 17, 589-602.

Atkinson, G.D. and C.R. Holliday, 1977: Tropical cyclone minum sealevel pressure/maximum sustained wind relationship for the westernNorth Pacific. Monthly Weather Review, 105, 421-427.

Crutcher, H.L. and R.G. Quayle, 1974: Mariner's worldwide climaticguide to tropical storms at sea. NOAA/EDS National Climatic Centerand Naval Weather Service publication (NAVAIR50-IC-61) , 114 pp.plus 312 charts.

Louisiana

Dvorak, V.F., 1973: A technique for the analysis and forecasting oftropical cyclone intensities from satellite pictures. NOAATechnical Memorandum NESS-45, 19 pp. -

--,

1975: Tropical cyclone intensity analysis and forecasting fromsatellite imagery. Monthly Weather Review, 103,420-430.

Hebert, P.J. and K.O. Poteat, 1975:nique for subtropical cyclones.SR-83, 25 pp.

A satellite classification tech-NOAA Technical Memorandum NWS

Jarvinen, B.R., C.J. Neumann, and M.A.S. Davis, 1984: A tropicalcyclone data tape for the North Atlantic basin, 1886-1983:Contents, Limitations, and Uses. NOAA Technical Memorandum NWS NHC22, 21 pp.

Lawrence, M.B.trochoidalReview, 105,

and B.M. Mayfield, 1977:motion during Hurricane,

1458-1461.

Satellite observations ofBelle 1976. Monthly Weather

Leftwich, P.W. and G.M. Brown, 1981: Eastern North Pacific tropicalcyclone occurrences during intraseasonal periods. NOAA TechnicalMemorandum NWS WR-160, 30 pp.

and C.J. Neumann, 1977: Statistical guidance on the predictionof Eastern North Pacific tropical cyclone motion -Part 2. .!!QMTechnical Memorandum NWS WR-125, 15 pp.

Mull, M.W., 1962: Tropical cyclones in the Eastern North Pacific,1961. Mariners Weather Log. 6, 44-46.

13

Neumann, C.J., 1975: A statistical study of tropical cyclone posi-tioning errors with economic applications. NOAA TechnicalMemorandum NWS SR-82, 21 pp.

--and P.W. Leftwich, 1911: Statistical guidance for the predictionof Eastern North Pacific tropical cyclone motion -Part 1. ~Technical Memorandum NWS WR-124, 32 pp.

padya, B.M., 1975: Spatial variability and gustiness of cyclonewinds: Gervaise, Mauritius, February, 1975. AustralianMeteorological Magazine, 23,61-69.

,Shaw, S.L., 1981: A history of tropical cyclones in the Central North

Pacific and the Hawaiian Islands, 1832-1979. Report NOAA--S/T81-168. Silver Spring, Maryland, 137 pp.

Sheets, R.C. and P. Grieman, 1975: An evaluation of the accuracy oftropical cyclone intensities and locations determined fromsatellite pictures. NOAA Technical Memorandum ERL WMPO-20, 36 pp.

Shinners, W., 1963: Comparison of measured and estimated winds atsea. u.S. Member Working Group on Technical Problems, Commissionfor Maritime Meteorology, WMO (unpublished manuscript).

u.s. Navy, 1956-1980:Command Center,Islands.

Annual Typhoon Reports. U.S. Naval OceanographyJoint Typhoon Warning Center, Guam, Mariana

u.s. Navy Oceanography Office, 1966: Handbook of Oceanographic Tables.SP-68, Washington, D.C., 427 pp.

14

APPENDIX I. TERMINOLOGY

EXTRATROPICAL CYCLONE:nontropical environment.cane force.

Tropical cyclone modified by interaction withNo wind speed criteria. May exceed hurri-

GMT.: Greenwich Mean Time. Also called "z" or Zulu time. Mean solartime of the meridian at Greenwich, England, used as the basis forstandard time throughout the world.

HURRICANE: A tropical cyclone of which the center (eye) is the war-mest area (warm-core) and in which the maximum sustained surface wind(l-minute mean) is ~ 64 knots (119 km/h).

!NOT.:

A unit of speed equal to 1 nautical mile per hour. One nauti-cal mile per hour is equivalent to 1.1508 statute mph or 0.5144 m/s.

A pressure unit of 1000 dyne/cm2, convenient for reportingpressures. The average sea-level surface pressure is

TROPICAL CYC~9~E: A nonfrontal low pressure system developing overtropical or subtropical waters and having a closed circulation ofwinds rotating counterclockwise in the Northern Hemisphere (clockwisein the Southern Hemisphere). This term encompasses tropicaldepressions, tropical storms, and hurricanes.

in which maximumthe

TROPICAL STORM: A tropical cyclone in which the center is the warmestarea (warm-core) and in which the maximum sustained surface windranges from 34 to 63 knots (63 to 117 km/h).

15

APPENDIX II. A SAMPLE FORTRAN PROGRAM TO READ AND WRITE THE DATA

DIMENSION REC(20)

cc

THIS PROGRAM ASSUMES THAT THE DATA TAPE IS MOUNTED ON UNIT 3 ANDTHAT THE LINE PRINTER IS UNIT 6.

REWIND 3

c INITIALIZE RECORD COUNTER

NRECS = 0

5 CONTINUE

c READ ONE RECORD AT A TIME

READ(3,lO,END=30) REC

c

'END=30'

STOPS READING OF TAPE AT 'END OF FILE' (EOF)

10 FORMAT(20A4)

c COUNT RECORDS.

NRECS = NRECS + 1

c PRINT DATA IN EACH RECORD

WRITE(6,lS) REC

15 FORMAT(10X,20A4)

GO TO 5

30 CONTINUE

WRITE(6,35) NRECS

35 FORMAT(35X, 19HNUMBER OF RECORDS =, 16)

REWIND 3

STOP

END

16