NOAA Techni ca 1 ~1emorandum NWS NHC 22

A TROPICAL CYCLONE DATA TAPE FOR THE NORTH ATLANTIC BASIN,

1886-1983: CONTENTS, LIMITATIONS, AND USES

Brian R. Jarvinen, Charles J. Neumann, and Mary A. S. DavisNHC, r1iami, Florida

National Hurricane Centerr.1i ami, Flori daMarch 1984Second Printing, October 1988

UNITED STATESDEPARTMENT OF COMMERCEC. William Verity, Secretary

National Oceanic and AtnKJspheric AdministrationWilliam E. EvansUnder Secretary and Administrator

National Weather ServiceElbert W. FridayAssistant Administrator

CONTENTS

.i i iDefinitions

1Abstract

1Introduction

1Background! of data set

The history of data observations 2

4Positions

7Windspeeds

9Pressures

10Data formats

13Use s 0 f t hie d a t a

17References

19Appendix I A sample program to read and write HURDAT .

DEFINITIONS

Cyclone: An atmospheric closed-circulation rotating counterclockwisein the Northern Hemisphere.

Extratropi~al Stage: In tropical meteorology this refers to thetransformation of a tropical cyclone from a warm core to a cold coresystem. This process usually occurrs poleward from the belt oftropicall easterlies.

GMT: Greenwich Mean Time. Also referred to as "z" time or Zulu time.--M"ean solar time of the meridian at Greenwich, England, used as the

basis for standard time throughout most of the world.

Hurricane_: A warm-core tropical cyclone in which the maximum sustainedsurface wind (l-min mean) is > 64 kt.

h-l It is

~llibar_: A pressure unit of 1000 dyn cm-2atmospheric pressures.

,

convenient for reporting

Subtropical Cyclones: Nonfrontal, low pressure systems that compriseinitially baroclinic circulations developing over subtropical waters.There are two types: (1) A cold low with circulation extending to thesurface layer and maximum sustained winds generally occurring at aradius of about 100 mi or more from the pressure center. These cy-clones sometimes undergo a metamorphosis and become tropical stormsor hurricanes. (2) A mesoscale cyclone originating in or near afrontolyzing zone of horizontal wind shear, with radius of maximumsustained winds generally less than 30 mi. The entire circulationsometimes encompasses an area initially no more than 100 mi in dia-meter. these marine cyclones may change in structure from cold towarm core. While generally short-lived, they may ultimately evolveinto major hurricanes or into extra-tropical cyclones.

Subtropical cyclones are classed according to intensity as follows:a. Subtr~pical Depression: A subtropical cyclone in which the maxi-

mum sustained surface wind (l-min mean) is ~ 33 kt.b. Subtr~pical Storm: A subtropical cyclone in which the maximum

sustained surface wind (l-min mean) is> 34 kt.

Tropical Clclone: A nonfrontal low pressure system of synoptic scaledeveloping over tropical or subtropical waters and having definiteorganized circulation.

Tropical Depression: A tropical cyclone in which the maximum sustainedsurface wind (l-min mean) is ~ 33 kt.

Tropical SEorm: A warm-core tropical cyclone in which the maximumsustained surface wind (l-min mean) ranges from 34 to 63 kt.

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: The I un i t 0 f 8 pee din the n aut i c a 1 8 Y 8 t em; 1 n. mi.equal to 1.1508 mi h-1 or 0.5144 m 8-1.

A TROPICAL CYCLONE DATA TAPE FOR THE

NORTH ATLANTIC BASIN,1 1886-1982:

CONTENTS, LIMITATIONS, AND USES

Brian R. Jarvinen, Charles J. Neumann, and Mary A.NWS, National Hurricane Center, Miami, Florida

S. Davis

ABSTRACT

The National Hurricane Center maintains a computer file onNorth Atlantic tropical cyclones. The file contains dates,tracks, wind speeds, and central pressure values (if avai-lable) for all tropical cyclones occurring over the 98-yearperiod, 1886 through 1983 and is updated annually. Thedata organization, format, and limitations are discussedand several uses of the data are demonstrated.

INTRODUCTION

The National Hurricane Center (NHC) is essentially a forecastingtrather than a data collectingt agency of NOAA. Howevert pursuant toits operational responsibility in the detectiont trackingt and fore-casting of tropical cyclonest and its additional responsibility in theapplied re$earch and public service areat the Center maintainsdetailed computer files on North Atlantic tropical storms and hurri-canes. This report describes the contentt formatt limitationst anduses of the data, hereafter referred to as the HURDAT (HURricane DATa)data set.

2. BACKGROUND OF DATA SET

The initial requirement for computerized tropical cyclone data at NHCcan be traced to a requirement of the NASA Space Program in the mid-1960's.

At the request of Space Program officials, Hope and Neumann(1968) of the Spaceflight Meteorology Group, formerly collocated withthe Nation~l Hurricane Center, studied the climatological impact oftropical cyclones on launches of space vehicles from the Kennedy SpaceCenter.

An extension to the authors' studies led to the operationalHURRAN (HURRicane ANalog) program (Hope and Neumann, 1970) for theprediction of tropical cyclone motion out through 72 hr.

Originally, Hope and Neumann based their studies on a now obsoletecard deck 988 (CD 988) obtained from the National Climatic Center.

IThe North Atlantic tropical cyclone basin includes most of the NorthAtlantic, Gulf of Mexico, Caribbean Sea, and adjacent land areas.

However, the original card deck has been extensively revised by NHCand tailored to its specific needs. Under the sponsorship of the U.S.Navy, the National Climatic Center has also revised card deck 988 andreissued it as card deck 993. The tropical cyclone tracks for the1886 through 1963 portion of this latter deck correspond to thosegiven by Cry (1965). The tropical cyclone tracks in HURDAT correspondto those given by Neumann, et al. (1981) in a revision to Cry, inwhich tracks are extended through the 1980 hurricane season. Therevision also includes a few changes to some of Cry's original tracks.A copy of this data set may be purchased from NOAA/NESDIS, NationalClimatic Center, Federal Building, Asheville, NC, 28801. Inrequesting the tape, specific referrence should be made to the NHCedition.

3.

THE HISTORY OF DATA OBSERVATIONS

The four basic pieces of information recorded on the computer file arethe tropical cyclone's position (latitude and longitude), maximumsustained wind speed in knots, the central pressure in millibars (ifavailable), and the time and date. The availability and accuracy ofthese parameters has by no means been constant throughout the years.Figure 1 indicates graphically the technical advances in observingsystems that have occurred since the formation of the HurricaneWarning Service in 1871. This figure shows that, until organizedreconnaissance began in 1944, the two major sources of information ontropical cyclones were land stations and ships at sea. Undoubtedly,during this early period some storms went undetected. However, shipsencountered tropical cyclones more frequently in earlier years becausethey did not always have the benefit of forecasts. Many times a stormwas detected and then "lost" for several days before it was encoun-tered by another ship or observed from a land station. At other timesa storm moved over land stations and through the major shipping lanes,thus allowing its track and intensity to be determined with a reaso-nable degree of accuracy. Therefore, during this early period of datathe most useful information is track rather than wind data, althoughsome of the tropical cyclones do have useful maximum wind information.Nevertheless, the user of the wind information is cautioned not tomake an overly precise interpretation of this parameter for the entireperiod of record and especially before 1944. The reader is referredto Neumann, et a1. (1981) for a list of additional references on tro-

pical cyclone tracking.

Organized aircraft reconnaissance has allowed continuous monitoring ofthe storm's track, maximum sustained wind field, and central pressure.This is reflected in the increase of pressure data beginning in 1944.The coastal radar network has improved the track information mainlyfor landfalling storms.

The largest single advance in the detection and tracking of tropicalcyclones has been the introduction of weather satellites with theirassociated visible and infrared sensors. With the initial position ofa tropical cyclone determined from satellite a reconnaissance aircraftis dispatched to measure the more precise wind field, centralpressure, and location of the center.

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Radar center estimates for tropical cyclone Anita, 1977.The Galveston radar was able to make several estimatesbefore the cyclone passed out of its range and into Browns-ville's range. Note the small-scale oscillations in thetrack and compare this with the best track in Figure 2.

Figure 3.

First, small-scale oscillatory (trochoidal) motions which are tran-sitory in nature and not representative of the more conservativemotion of the entire storm envelope must be considered. Smoothing isnecessary to remove these small-scale motions, which are on the orderof 5 to 20 n.mi. about some mean path. Radar documentation of theseeye oscillations on tropical cyclone Carla, 1971, is presented inFigure 4. Recent evidence of similar motion based on satellite ima-gery of tropical cyclone Belle, 1976, is provided by Lawrence andMayfield (1977). Therefore, final tracks should be considered as thebest estimate of the larger scale storm motion, rather than precise

locations of the eye.

-5-

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Portion of hurricane Carla track over Gulf of Mexico show-ing four smoothed trochoida1 oscillations of storm center.Track is based on "fixes" from three coastal radars. Heavytrack, offset to northeast, shows portion of smoothed "besttrack". Range markers are at 20-n.mi. intervals. (Figureadapted from Weatherwise., October, 1961.)

Figure 4.

When an analyst has finished constructing a best track, storm posi-tions at 6-hour1y intervals are noted. The times for the four posi-tions per day are (0000, 0600, 1200, and 1800) Greenwich Mean Time(GMT). These are the positions that are stored on the BURDAT tape.Each position is given by latitude and longitude to the nearest tenth

of 1 degree.

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Before 1931, only 1200 GMT positions were recorded on the originalcard deck 988 (see page 1). The three intermediate positions wereinterpolated from the 1200 GMT positions. From 1931 through 1956,although four positions per day were determined by the forecaster,only the 0000 and 1200 GMT positions were recorded. Here it wasnecessary to interpolate for the 0600 and 1800 GMT positions. Anonlinear interpolation scheme was used to obtain these intermediatepositions. The polynomial interpolation described by Akima (1970)gave highly satisfactory results. However, each track interpolationwas carefully checked to insure that important features, such as loopsin the track, were retained.

Beginning in 1956, storm positions were recorded four times per dayfor verification of official forecasts which are also issued fourtimes per day. The need for these positions increased during the1960's with the coming of the computer age; they are required for manypurposes, such as computer plotting of the tracks, implementation ofthe operational models, verification of the forecasts from the opera-tional models, and verification of the official forecasts.

5. WIND SPEEDS

Each of the four daily storm positions has a corresponding wind speed.These wind values are specified in knots and rounded to the nearest5-kt value, i.e., 68 kt becomes 70 kt while 67 kt becomes 65 kt. Thewind values are estimated or measured averages over a I-min period.Therefore, these values are not the peak winds or gusts. For furtherinformation on the relationship of gusts to average winds, the readeris referred to Dunn and Miller (1964), pp. 61-67; Padya (1975); andAtkinson and Holliday (1977).

To understand the limitations of the wind speed values, it is instruc-tive to explore the various means by which the different observingplatforms have actually measured the wind. First, for land stations,several types of wind recording devices have been used over the periodof record. For example, in the 1890's, triple register instrumentswere introduced. The wind speed was one of the parameters measuredand recorded by a counter device utilizing a 3-cup anemometer. In the1950's, the present day recording device used by the National WeatherService was introduced. Known as the F-420 system, it measures windspeed and direction and also records wind gusts. Several other typesof anemometers have been used in the recording of the maximum windspeed. These include 4-cup and 22-cup anemometers, it is felt thatlarger errors are introduced by the location and height of a par-ticular anemometer.

The locations and heights of anemometers have varied at NationalWeather Service stations as the stations have been moved. The expo-sure of the anemometer to buildings can be very significant. Forexample, during the most destructive storm in the history of Miami,Florida, in 1926, the official recording anemometer was betweenseveral large buildings. It was estimated by the meteorologist incharge that the wind values recorded were approximately one-half ofthe actual value.

-7-

It should be noted that the chance of a tropical cyclone passingdirectly over a fully instrumented facility is remote. On many occa-sions, even when a storm passes over a populated area, the maximumwind must be inferred from indirect evidence, such as peripheral windmeasurements or damage profiles.

Estimations of the wind over the ocean by ships are determined by thestate of the sea and given in the Beaufort scale. Over the past 30years some ships have been instrumented with anemometers. However,because the ship is a moving platform (in three directions), correc-tions are necessary to determine a wind value. The state-of-the-seadetermination is a one-step observation and is thus favored by mari-ners.

A study by Shinners (1963) found that anemometer-measured windsversus state-of-the-sea-determined winds were (1) lower up to about 20kt, (2) approximately the same from 20 to 30 kt, and (3) greater above30 kt. In other words, state-of-the-sea-determined winds are under-estimates of the actual wind at higher speeds. The magnitudes ofthese underestimates are approximately 6 kt for the range 36 to 45 kt,13 kt for the range 46 to 55 kt, and 15 kt for the range 56 to 65 kt.However, both types of wind values are received in ship reports today.

Likewise, although aircraft reconnaissance measures the flight-levelwinds anywhere from 500 to 10000 ft, the surface winds are a subjec-tive estimate based upon observation of the sea state and/or tablesrelating flight-level winds to surface winds.(Black and Adams, 1983)

Finally, wind speed values were computed on occasions from pressurevalues using the formula (Kraft. 1961):

where:

Vmax = maximum sustained wind

and

Pcenter = pressure at center in millibars

Since the advent of weather satellites, techniques have been developedby Dvorak (1973 and 1975) and Hebert and Poteat (1975) to determinewind speed from the shape of a tropical and subtropical cyclone'scloud field, respectively. This estimation, along with those receivedfrom aircraft reconnaissance, forms the main nucleus of information todetermine the final wind field. Figure 5 contains final surface windand pressure profiles for tropical cyclone Anita, 1977. Also shownare the original surface wind and pressure information which was usedto determine the profiles. Time increases to the right. The windspeed is specified in knots and pressure in millibars. The scatterand discrepancies in the various wind reports is quite evident. Here,again, as in the best track determination, the analyst subjectivelydetermines the profiles. It is extremely important for the analyst tounderstand the weaknesses and strengths of the various measuring plat-forms.

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Figure 5. Final wind (dashed line) and pressure (solid line) profileswith actual data for tropical cyclone Anita, 1977.

6. PRESSURES

The tropical cyclone's central pressure on HURDAT is specified inmillibars. Only reported central pressures within +2 hr of one of thefour reporting times are included in the data. As discussed earlier,the frequency of pressure values decreases as one goes back in theperiod of record. Thus, unlike wind speeds, central pressures areoften missing.

Pressures at populated centers affected by a storm may be well docu-mented, even though the eye of the storm passed a good distance away.Those pressures ~ ~ part of this data set. It should be empha-sized that all pressures on HURDAT are observed and that no pressureswere determined from the winds.

Figure 5 shows a pressure profile and actual pressure data used todetermine this profile. Since the satellite intensity classificationdetermines the maximum sustained winds only, no pressure values are

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given.

It is clearly evident from the raw pressure data that thecentral pressure is a much more conservative property of the tropicalcyclone than the wind field.

7 . DATA FORMATS

The master deck that was used to generate the computer file consistedof three types of cards: Title, Data, and Classification. Each stormhas one title card containing all required information to identify it.The first item on the card is the sequence number. The month, day,and year follow in that order. This is the first day on record forthe storm. The next three numbers refer to the number of days thestorm was in existence (M), the storm number for that year, and thecumulative storm number (SNBR), where the first storm in 1886 is 1 andthe last storm in 1983 is 815. The next variable is the storm name.Before the naming of tropical storms in 1950, a "not named" messagefills the space on the cards. The next item on the card is a stormcrossing index (XING). The final item on the card is theSaffir/Simpson Hurricane Scale (SSS). In the present version thisnumber should be ignored before 1899. To relate hurricane intensityto damage potential, the National Hurricane Center has adopted theSaffir/Simpson Hurricane Scale. This descriptive scale, over a rangeof categories 1 through 5, is shown in Table 4. Saffir/Simpson scalenumbers are given only for hurricanes that crossed the continentalUnited States. In a few instances, a Saffir/Simpson number of zeroappears. This indicates that the storm, although classified as ahurricane over coastal waters, weakened to below hurricane strengthbefore crossing the immediate coast line. On the title card, column80 is used to denote the last storm of the year if punched with an L.

The single Title card is followed by two or more Data cards, one foreach GMT day of the storm's existence. Each contains four sets ofnumbers where each set contains the storm type, the storm position(latitude in degrees north and longitude in degrees west), wind speed,and the central pressure. The sets correspond to the times 0000,0600, 1200, and 1800 GMT. The storm types are *-Tropical Storm orHurricane, D-Tropical Disturbance, S-Subtropical Storm, W-TropicalWave, and E-Extratropical Storm.

The Classification card's purpose is to classify the maximum statusattained during a storm's life. The index can take on one of threevalues: Tropical Storm (TS), Hurricane (HR), or Subtropical Storm(SS) .

Tables 1 through 3 indicate the exact location of each parameter onthe three types of cards. Copies of the computer cards for Anita,1977, and an unnamed tropical storm, 1937, are shown in Figure 6.Note the difference in the amount of central pressure data.

The record size on the magnetic tape is 80 bytes, (i.e., each recordis a card image.) This allows the user to read the tape as if it werea card deck. The user may then want to store certain information inlarger records which will reduce input/output time. A fortran programto read and write the HURDAT tape, with formatted input and outputstatements, is given in Appendix I. The necessary physical parametersfor reading the tape (i.e., density, parity, etc.) will be supplied bythe National Climatic Center along with the tape.

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Table 1. Title Card -Format and Contents

17-

101320233136

Card s,equence numberMonthDay (first day of storm on record)YearValue of M (M=number of days storm existed)Storm number for that yearCumulative storm numberStorm nameCrossing (l=hit u.S. coastline, O=did not)Saffir/Simpson Hurricane Scale numberLast storm of year if 1

---~ -Table 2. Storm Data Card -Format and Contents

--Latitudes and longitudes are rounded to the nearest tenth.Wind speed is rounded to the nearest 5 kt.Pressure is rounded to the nearest millibar.---

Computer Card Columns Contents

1

1122

3334

4555

6677

Card sequence numberMonthDayStorm type at OOOOZLatitude at OOOOZLongitude at OOOOZWind speed at OOOOZCentral pressure at OOOOZStorm type at 0600ZLatitude at 0600ZLongitude at 0600ZWind speed at 0600ZCentral pressure at 0600ZStorm type at l200ZLatitude at l200ZLongitude at l200ZWind speed at l200ZCentral pressure at l200ZStorm type at l800ZLatitude at l800ZLongitude at l800ZWind speed at 1800ZCentral pressure at l800Z

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4726

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Table 3. Classification Card -Format and Contents

Computer Card Column Contents

1 -57 -8

Card sequence numberMaximum status of storm during its life

Table 4. Saffir/Simpson Hurricane Scale

Category Number Definition

Winds of 74 to 95 miles per hour. Damage primar-ily to shrubbery, trees, foliage, and unanchoredmobile homes. No real damage to other structures.Some damage to poorly constructed signs. And/or:storm surge 4 to 5 feet above normal. Low-lyingcoastal roads inundated, minor pier damage, somesmall craft in exposed anchorage torn from moor-

ings.

1

Winds of 96 to 110 miles per hour. Considerabledamage to shubbery and tree foliage; some treesblown down. Major damage to exposed mobile homes.Extensive damage to poorly constructed signs.Some damage to roofing materials of buildings;some window and door damage. No major damage tobuildings. And/or: storm surge 6 to 8 feet abovenormal. Coastal roads and low-lying escaperoutes inland cut by rising water 2 to 4 hoursbefore arrival of hurricane center. Considerabledamage to piers. Marinas flooded. Small craftin unprotected anchorage torn from moorings.Evacuation of some shoreline residences and low-lying island areas required.

2

Winds of 111 to 130 miles per hour. Foliage tornfrom trees; large trees blown down. Practicallyall poorly constructed signs blown down. Somedamage to roofing materials of buildings; somewindow and door damage. Some structural damageto small buildings. Mobile homes destroyed.And/or: storm surge 9 to 12 feet above normal.Serious flooding at coast and many smaller struc-tures near coast destroyed; larger structuresnear coast damaged by battering waves and float-ing debris. Low-lying escape routes inland cutby rising water 3 to 5 hours belfore hurricanecenter arrives. Flat terrain 5 feet or lessabove sea level flooded inland 8 miles or more.Evacuation of low-lying residences within severalblocks of shoreline possibly required.

3

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--.Table 4. Saffir/Simpson Hurricane Scale continued

4 Winds of 131 to 155 miles per hour. Shrubs andtrees blown down; all signs down. Extensive dam-age to roofing materials, windows and doors.Complete failure of roofs on many small residen-ces. Complete destruction of mobile homes. And/or: storm surge 13 to 18 feet above normal. Flatterrain 10 feet or less above sea level floodedas far as 6 miles. Major damage to lower floorsof structures near shore due to flooding and bat-tering waves and floating debris. Low-lying es-cape routes inland cut by rising water 3 to 5hours before hurricane center arrives. Majorerosion of beaches. Massive evacuation of allresidences within 500 yards of shore possiblyrequired, and of single-story residences on lowground within 2 miles of shore.

5 Winds greater than 155 miles per hour. Shrubsand trees blown down; considered damage to roofsof buildings; all signs down. Very severe andextensive damage to windows and doors. Completefailure of roofs on many residences and industri-al buildings. Extensive shattering of glass inwindows and doors. Some complete building fail-ures. Small buildings overturned or blown away.Complete destruction of mobile homes. And/or:storm surge greater than 18 feet above normal.Major damage to lower floors of all structuresless than 15 feet above sea level within 500yards of shore. Low-lying escape routes inlandcut by rising water 3 to 5 hours before hurricanecenter arrives. Massive evacuation of residenti-al areas on low ground within 5 to 10 miles ofshore possibly required.

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8. USES OF THE DATA

This section highlights some of the uses of the HURDAT tape at theNational Hurricane Center. The thousands of requests received overthe years indicate a much broader usage of the data than presentedhere.

The most requested products are the tracks. Figure 7 shows the tracksfor all tropical cyclones beginning September I through 5, 1886through 1977.

Figure 7. Tracks of tropical cyclones originating September 1 thrt Ugh

5, 1886 through 1977.

There are frequent requests for all tropical cyclones passing With ~ n a

given distance from a particular location. Figure 8 shows all tra ks

of tropical cyclones of hurricane intensity when they were within 0n.mi. of Miami, Florida, for 1886 through 1983. Table 5 is a copy of

the printout giving additional information, such as the point and timeof closet approach of the tropical cyclone to Miami and the maximu*wind within the 50 n.mi. circle. A legend is included to explain t achvalue in the table.

-15-

Tracks of all tropical cyclones of hurricane intensitypassing within 50 n.mi. of Miami, Florida. The 50 n.mi.circle is also plotted. The numbers at the beginning andend of each track refer to column 1 of Table 4.

Figure 8.

Standard statistical graphs showing frequency for various periods areoften produced. Figure 9 gives an example of the annual tropicalcyclone frequency, 1886 through 1982.

-16-

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These are determined from the scatter of the analog composites at therespective forecast interval. Other forecast models use the climato-logical information as one of many pieces of information to determinea forecast track.

Uses of the data also include intensity forecasts from regression ana-lyses of the wind data and determination of pressure wind

relationships.

REFERENCES

Akima, H., 1970: A New Method of Interpolation and Smooth Curve Fit-ting Based on Local Procedures, Journal of the Association for Com-puting Machinery, Vol. 17, No. 4, pp. 589-602.

Atkinson, G. D. and C. R. Holliday, 1911: Tropical Cyclone MinimumSea Level pressure/Maximum Sustained Wind Relationship for theWestern North Pacific, Monthly Weather Review, Vol. 105, No.4,421-421.

Black, P.G. and W.L. Adams, 1983: Guidance for Estimating SurfaceWinds Based on Sea State Observations from Aircraft and Sea StateCatalog, Special Report from the Federal Coordi~a~~;_fo~ M~~eoEo-logical Services and Supporting Research, FCM-Gl-1983, Washington,D.C., 83 pp.

Cry, G. W., 1965: Tropical Cyclones of the North Atlantic Ocean,Technical Paper No. 55, u.s. Weather Bureau, Washington, D.C.,

pp.

Dunn, G. E. and B. I. Miller, 1964: Atlantic Hurricanes, LouisianaState University Press, Baton Rouge, LA, 377 pp.

Dvorak, V. F., 1973: A Technique for the Analysis and Forecasting ofTropical Cyclone Intensities from Satellite Pictures, NOAA Techni-cal Memorandum NESS-45, Washington, D.C., 19 pp.

, 1975: Tropical Cyclone Intensity Analysis and Forecastingfrom Satellite Imagery, Monthly Weather Review, Vol. 103, No.5

pp. 420-430.

Hebert, P. J. and K. O. Poteat, 1975: A Satellite ClassificationTechnique for Subtropical Cyclones, NOAA Technical Memorandum NWS

~

SR-83, Fort Worth, Texas, 25 pp.

Hebert, P. J. and G. Taylor, 1975: Hurricane Experience Levels ofCoastal County Populations -Texas to Maine, Special Report, 153

pp.

Hope, J. R. and C. J. Neumann, 1968: probability of Tropical CycloneInduced Winds at Cape Kennedy, Weather Bureau Technical MemorandumSOS-I, Silver Spring, MD, 67 pp.:

and , 1970: An Operational Technique for Relating theMovement of Existing Tropical Cyclones to Past Tracks, MonthlyWeather Review, Vol. 98, No. 12, pp. 925-933.

-19-

Kraft, R.H., 1961: The Hurricane's Central Pressure and Highest Wind,Mariners Weather Log, Vol. 5, No.5, 157 pp.

Lawrence, M. B. and B. M. Mayfield, 1977: Satellite Observations ofTro~hoidal Motion During Hurricane Belle 1976, Monthly Weather I.Rev1ew, Vol. 105, No. 11, pp. 1458-1461. r

Neumann, C. J., G. W. Cry, E. L. Caso, and B. R. Jarvinen, 1981: ITropical Cyclones of the North Atlantic Ocean, 1871-1980, 174 Pt.

padya, B. M., 1975: Spatial Variability and Gustiness of CycloneWinds: Gervaise, Mauritius, February 1975, Australian Meteorolo$i-ca1 Magazine, Vol. 23, No.3, pp. 61-69.

Saffir, H. S., 1911: Design and Construction Requirements for Hurri-cane Resistant Construction, American Society of Civil Engineers,New York, Preprint Number 2830, 20 pp.

I

Shinners, W., 1963: Comparison of Measured and Estimated Winds atSea, U.S. Member Working Group, WMO, (unpublished manuscript).

U.S. DOC, NOAA, Federal Coordinator for Meteorological Services an~Supporting Research, 1911: National Hurricane Operations Plan, FCM

11-2, 104 pp. I

-20-

APPENDIX I A SAMP~E PRpGRAM TO READ AND WRITE HURDAT

DIMENSION IDATE(50,5) ALAT(50,4),ALON(50,4),IPED(50,4),IPRE(50,4)DIMENSION IA(19),IB(5 ),ICf(50,4)WRITE(6,1) !

1 FORMAT(IHl)DO 50 1=1,1000EACH PASS THROUGH DO OOP 0 READS ONE STORMREAD(19,2,END=99) (IA J),J 1,19),M,(IB(J),J=I,58),LSTORM19=HURDAT TAPE. READ TITL CARD. OBTAIN M WHICH GIVES THENUMBER OF GMT DAYS TH T TH STORM WAS IN EXISTENCE.

2 FORMAT(19Al,I2,58Al,1 ,AI)DO 7 II=I,MDO LOOP 7 READS M DAT CAR S AND STORES VALUES IN ARRAYS.READ(19,5) (IDATE(II,J),J= ,5),«ICE(II,J),ALAT(II,J),ALON(II,J),

lIPED(II,J),IPRE(II,J»,J=14)5 FORMAT(6X,5Al,4(Al,F3.1,F4 1,IX,I3,IX,I4»7 CONTINUE

READ(19,8) IQREAD IDENTIFICATION C RD

8 FORMAT(6X,A2)

c

cc

c

c

cccc

DATA FOR ONE STORM RE~D INTO STORAGE.WRITE THIS DATA OUT. I l

THE FOLLOWING STATEMENTS

WRITE(6,11)WRITE(6,12) (IA(J),J=7,19) M,(IB(J),J=I,59)DO 9 J=l,MWRITE(6,13) (IDATE(J,K),K= ,5),«ICE(J,K),ALAT(J,K),ALON(J,K),

lIPED(J,K),IPRE(J,K»,K 1,49 CONTINUE

11 FORMAT(IHO,/,/,/,2X,40 )12 FORMAT(IHO,10x,13Al,I2,59A ,/,/,20X,5HOOOOZ,17X,5H0600Z,17x,

15HI200Z,17X,5HI800Z,/,/,27X,4HDATE,2X,4(3HLAT,3X,3H ON,2X,3HVEL,IX,4HPRES,3X»

13 FORMAT(IH ,5X,5Al,IX,4(Al, 4.1,IX,F5.1,IX,I3,IX,I4,2X»50 CONTINUE99 CONTINUE 1!

STOPEND

-21-