[From the U.S. Government Printing Office, www.gpo.gov]
NOAA TM NWS SR 58 A UwIe gmAT DEPRAITMET OF PUBUCATION irf- d NOAA Technical Memorandum NWS SR-58 U.S. DEPARTMENT OF COMMERCE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION National Weather Service ATLANTIC HURRICANE FREQUENCIES ALONG THE U. S. COASTLINE R. H. SIMPSON and MILES B. LAWRENCE 3 '~ :. .,'-~ U.S. DEPARTMENT OF COMMERCE NOA; COASTAL SERVICES CENTER -..o '= 2234 SOUTH HOBSON AVENUE , ~ CHARLESTON SC 29405-2413 QC (-> 995 .U67 no.58 Sthern Region c.2 property of CSC Library FORT WORTH, TEXAS ( June 1971 ODAA TECHNICAL ENIDRAUDA National Weather Service,Southern Eegion Suberies The National Weather Service Southern Region (SR) Subseries provides an inforsal msdium for the docrantation and quick dissemination of results not appropriate, or not yet ready, for formal publication. The seriee is used to report on work in progress, to describe technical procedures and practices, or to relate progress to a limited audience. These Technical Memoranda will report on investigations devoted primrily to regional and local problems of interest.mainly to personnel, and hence will not be widely cistributed. Papers 1 to 3h are in the former series, ESSA Technical Memoranda, Southern Region Technical Hemoraoda (SRN); papers 35 to 51 are in the former series, ESSA Technical Memoranda, Weather Bureau Technical Memoranda (WBTM). Beginning with 52, the papers are mow part of the series, NDAA Technical Memoranda NWS. Papers 1 to 35 are available from the National Weather Service Southern Region, Scientific Services Division, Ftos 10E09, Federal Office Bldg., 819 Taylor Street, Fort Worth, Tex. 76102. Beginning with 36, the papers are available from the National Technical Information Service, U. S. Department of Commerce, 5285 Port Royal Road, Springfield, Va. 22151. Price: $3.00 paper copyl $0.95 microfiche. Order by accession number shown in parenthesis at end of each entry. ESSA Technical Memoranda SRTM 1 Selection of Map Base for Small Scale Analysis and Prediction. Woodrow W. Dickey - May 1965 SRTM 2 The Relationship of K-Values to Areal Coverage of Showers in the Mid-South. Jack Hollis and aenneth S. Bryan - August 1965 SRTM 3 Some Notes on Waterspouts around the Lower Keys. R. Larry Mayne - August 1965 SRTNM Tornadoes Associated with Cyclones of Tropical Origin - Practical Features. E. L. Hill, William Malkin and W, A. Sohuls, Jr. - September 1965 SRTM 5 Radar Exhoes Associated with Waterspout Activity. Dorus D. Alderman - October 1965 SRIM 6 Probability Forecasting. Woodrow W. Dickey - October 1965 SRTN 7 Short Period Forecasting. Jeter A. Pruett - Noveber 1965 SRTI 8 Southwest Texas Soaring Weather. David H. Owens - November 1965 SRKT 9 A Survey of Research in Agricultural Meteorolosgy. Donald A. Downey - November 1965 SRTM 10 A Quick Look at the Results of One Month's Precipitation Probability Forecsting. George T. GOrgg - Janury 1966 SRKM 1U Severe Storm Wkrning Systems in the Southern Region. Staff Metbers of Operation Division, Southern Region - February 1966 SRIN 12 The Lubbock Snowstors of February 20, 1961. Billie J. Cook - April 1966 SRTW 13 Sumry of Probability of Precipitation Forecasts in the Southern Region for the Period January through March 1966. Wodrow W. Dickey - May 1966 SRTM 1l Air Po4ution Meteorology and Transport of Pollutants. Jong A. Colon - Jun 1966 SRTN 15 On the Mechanism for the Production of Rainfall in Puerto Rico. Joe A. Coldn - June 1966 SRTM 16 Teletype Techniques and Presentation Procedures for Public Weather Circuits. Jack Riley - June 1966 SRTM 17 Summury of the Pre-FP - Post-FP Forecast Verification Experiment. Woodrow W. Dickey - June 1966 SRTD 18 Fire Weather in the Southeast. Richard A. Mitheb - July 1966 SRTI 19 Severe Storm Warning Networks in Oklahoma. Gerald J. Carter and W. O. Grrison - July 1966 SRTM 20 Climatological Aids to Short Range Forecasting. Jerome H. Codngton - August 1966 SRTM 21 A Review of the Methods Developed for Feorecasting Stratus in South Central Tes. Richard S. Sohrag - August 1966 SRTM 22 Agricultural Forecasting at Tallahassee, Florida. J. S. Smith - August 1966 SRTM 23 The Use of Radar in Flash Flood Forecasting. Jack L. Teague - August 1966 SRTM 2h Short Range Forecasting Procedures at Savannah. David P. Barnes - August 1966 SRTM 25 On the Use of Digitized Radar Data for the Florida Peninsula. Neil L. Frank, Paul L. Moore, and George e. Fisher - September 1966 SRTM 26 Relative Humidity in Georgia. Horace S. Carter - September 1966 SRTM 27 Study on Duration of Measurable Precipitation at Birmingham. Hugh B. Riley - September 1966 SRIM 28 The Weather Distribution with Upper Tropospheric Cold Lows in the Tropics. Neil L. Frank - September 1966 SATM 29 On the Correlation of Radar Echoes over Florida with Various Meteorological Paramters. Neil L. Frank and Daniel L. Smith - October 1966 SRTM 30 A Study of the Diurnal Summr Wind System at Galveston, Texs. David H. George - Deceber 1966 SRTM 31 A Simple Inexpensive Degree-Hour Counter. D. R. Davis and Jerrell E. Hughes - March 1967 SRTH 32 An Objective Technique for Forecasting the Possibility of an Afternoon Summr Shower at Saanah, Georgia. David P. Barnes, Jr. and Samuel C. Davis - March 1967 SRTH 33 An Empirical Method for Frsecasting Radiation Temperatures in the Lover Rio Grande Valley of Texas. Leroy B. Ragood � rch 1967 SRTM 34 Study on Duration of Measurable Precipitation at Lubbock, Tem. 0. Alan Johnson and Thomas P. Clarke - April 1967 iMBT SR 35 Reaoting Radar Scope Weather and Associated Data via the Slo-Scan Method. Davis Banton - May 1967 WMIM SR 36 Short Range Forecasting of Dryoff Time from Dew Block Dew Intensity. IDru D. Aldermn end enth . Bryan - October 1967 (PB 182 223) WBTM SR 37 The Relationship of I-Values to Probability of Showers in the Mid-South. Kennsth E. Bryan - October 1967 (PB 182 224) WSM SR 38 Florida Hurricanes. Gordon E. Duon and Staff NHC - Novoeber 1967 (PB 182 220) WBTM SR 39 The Relationship of Precipitation and Cloudiness to Some Predictors from the MC Six-Layer Model, Staff SSD, WBIRH - Octohr 1968 (PB 182 221) WBTM SR 40 A Preliminary Exuaination of Areal Characteristics of Precipitation in New Mxico. George T. Gregg - November 1968 (PS 182 222) WBTM SR 41 An Analysis of Hurricane Betsy. George A. Qusreau - January 1969 (PB 182 383) WbIT SR 12 Memorable Hurricanes of the United States Since 1873. Arnold L. Sugg ad Robert L. Crode �- Jnury 1969 (PB 182 228) WBTM SR 13 Applications of Coanity Antenna Television (CATV) Systaem to Public Weather Dissatation. L O. Reinhold and Carl IL Reber - January 1969 (PB 182 831) WBRT SR I4 Climatology of Atlantic Tropical Cyclones by Two and Ons-Half Degree Latitude-Longitude Bues. John R. Hope and Charles J. bann - February 1969 (PB 183 308) WBTH SR hS On the Madimum Sustained Winds Occurring in Atlantic Burricanes. Charles Holliday - May 1969 (PB 18h 609) WBTM SR 46 Hemispheric Circulation and Anomaly Patterns Observed When Tropical Storm Reach barricane Intensity. Paul J. Rebert, ME and Banner I. Miller, mIL - May 1969 (PB 18h 610) W-TM SR 47 Disturbances in the Tropical and Equatorial Atlantic. R. H. Sipeon - June 1969 (PB 184 7O0) WBTN SR 18 On Comparative Rating of Forecasters. George . Gregg - October 1969 (PB 188 039) WBHi SR 19 A Mean Storm Surge Profile. Arnold L. Sugg - December 1969 (PB 188 h22) WBiT SR 50 A Reassessment of the Hurricane Prediction Problm. Robert H. Simpson - February 1970 (PR 189 816) WBTK SR 51 The Satellite Applications Section of the National Hurricane Center. R. H. Simpo nd D. C. Gaby - September 1970 (OC 71 oOD5) 11AA TOchnical NMranda 0 WS SR 52 A Studr of Funnel Cloud 1ccurrencee in th BauamntPort Arthur-Orang Area in Tam. Carls GOars, Jr. - January 971 (C 71 00306) IW SR 53 The Decision Process in Hurricane Forecasting. R. L. Simpson - January 197, (0M 71 00336) Ni SR 5S Statistical Forecasts of Dow Point in Northeast Tex With Oneet of Southerly now. Toy V. Triable - ebruary 1971 (OM 71 00342) n Revised April 1971 -s NW SR 56 . 1- '(2 1 z 3a c q � ontism, on inside rear cover) U. S. DEPARTMENT OF COMMERCE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION NOAA Technical Memorandum NWS TM SR-58 ATLANTIC HURRICANE FREQUENCIES ALON3 THE U. S. COASTLINE SOUTHERN REGION HEADQUARTERS SCIENTIFIC SERVICES DIVISION FORT WORTH, TEXAS 1 June 1971 Atlantic Hurricane Frequencies Along the U.S. Coastline by R. H. Simpson and Miles B. Lawrence NHC, Coral Gables, Florida ABSTRACT From a recently completed climatology of hurricanes at the National Hurricane Center covering a period of 85 years of record, the total number of incidents and the frequency of hurricanes and tropical storms for 50-mile segments of the U. S. Gulf of Mexico and Atlantic coastlines are presented. INTRODUCTION The migration of our population toward the seacoasts imposes an in- creasingly important requirement for intelligently assessing the risks involved on hurricane-prone coastlines of the U. S. Tis paper attempts to present the best available data on the occurrence of hurricanes in such a manner that these risk assessments will be easier to make. In con- nection with the development of the HURRAN technique by Hope and Neumann (1970) and the development of a hurricane climatology for 2� degree squsres of latitude and longitude by Hope and Neumann (1969), the hurricane recora of the last 85 years was carefully reviewed. The principal source of ma- terial for this study-was the hurricane tracks and summary by Cry (1965). These data were stored on magnetic tape and now provide the basis for ntany climatological summaries and computations at the National Hurricane Center. From this tape, a compilation of tropical cyclone occurrences along the U.S. Gulf of Mexico and Atlantic coastlines has been prepared for coastal segments of 50 miles in length. The diagrams presented here summarize these data. The frequency of hurricanes along our coastlines is such that no cli- matological summary can be considered a stable assessment of the risk of storm recurrence at any one locality. Nevertheless, it is important that the best possible information be available for various planning purposes, and this document is directed toward that end. METHOD OF SUMMARIZATION For planning purposes, especially for metropolitan areas and for the location of industrial sites, the summarization of hurricane events needs to be made for the smallest practicable coastal sectors for which the re- sults may hold significance. In the present study, a review of all tropical 2 cyclone events for the period of 1886 - 1970, indicates that a 50-mile coastal strip is the smallest segment for which a meaningful summary can be made for the purpose of examining hurricane events. In some areas, even this size segnent involves a marginal number of storms. In s'anmarizing the data, it was assumed that if a tropical cyclone of hurricane intrusity crossed the coastline in one of the 50-mile sectors, it also affected t'?e adjacent sector which lay in the right semicircle of the storm. Fov e- ample, a hurricane which crossed the coastline in sector 2 (Fig. la) was counted not only for sector 2 but also for sector 3. It should be mentioned that only storms entering a coastal area were considered; i.e., the method of tabulation made it unwieldy to include those storms that were passing off shore. This is significant only for the State of Florida where an intense storm crossing the peninsula ~oid produce damaging winds along the coastal zone where this storm returns from land to sea. There have been a number of such cases over the years and, therefore, the data presented for peninsular Florida in this report may be regarded as somewhat conservative. Tropical cyclones were divided into three categories. One includes all cyclones whose maximum (reported) sustained winds were 40 mph (gale force) or higher. The second includes all tropical cyclones with reported winds of 74 mph (hurricane force) or higher, and the third, those great hurricanes with sustained winds of 125 mph or more. The latter maximum wind threshold carries with it the likelihood of severe structural dam- age to residences and small industrial plants where building codes spe- cifically designed to protect against a mature hurricane have not been enforced. The central pressure of approximately 950 mb, which normally accompanies this wind value, can be associated with storm surge heights as high as 12 to 15 feet where bottom depths and other coastal features 3. favor this accumulation. Thus, due to both storm surge inundation and wind stresses on structures, storms in this category can be expected to bring major disasters to metropolitan areas with heavy damage to struc- tures and high potential for loss of life. The summary figures presented in the next section refer to the fre- quencies of tropical cyclones. These frequencies are expressed as prob- abilities in percentage units. These values are not, of course, prob- abilities in the strict mathematical sense, but are the arithmetic means of the 85 year sample of data. A method of estimating the mathematical probabilities is to assume that the statistical properties of the data sample represent the proper- ties of the entire population of events (i.e., all coastline crossings). These statistical properties will then determine a particular distribu- tion of events. In the present case, the Poisson distribution is appro- priate, as demostrated by Hope and Neumann (1968), and also by Thom (1960). Table 1 shows the relation between the observed frequency of occur- rences of coastline crossings and the probability of occurrences of at least one storm crossing in a year as computed from the Poisson distri- bution. TABLE I Observed Frequency of Occurrence Versus Poisson Probability Observed Average Number of Poisson Probability of At Least Storm Crossings Per Year One Storm Crossing Per Year .00 .00 .01 .01 .02 .02 .03 .03 .04 .04 .05 .05 Table I (cont'd) 4. Observed Average Number of Poisson Probability of At Least Storm Crossings Per Year One Storm Crossing Per Year .06 .06 *07 .07 .o8 .o8 .o09 .09 .10 .10 .11 .10 .12 .11 *13 .12 .14 .13 .15 .14 .16 .15 .17 .16 .18 .16 .19 .17 .20 .18 .21 .19 It is seen from Table 1 that the difference between the observed averages and the Poisson probabilities is small, being no more than two percentage points, and this only at the high end of the range. Also, the Poisson probabilities, where different, are always a reduction from the observed frequencies. This is explained by the fact that the Poisson dis- tribution accounts for the possibility of more than one storm crossing during a single year. In view of the above, it seemed advisable to present the data and figures of this study in terms of the raw data; that is, the observed frequencies of occurrence, leaving the particular statistical application up to the potential user of these data. SUMMARY Figure la shows the locations of the coastline segments. With just a few exceptions (segment no. 12 for example), the coastal strips approx- imate 50 nautical miles in length. A list of the exact positions of the endpoints of the segments that were used in the computations are given in an Appendix to this report. Figure la indicates the dates of the earliest 582 52 -blow, 3~~~~~~ 9, _ ~~~ ~~f~~i49 6/3 2�~~~~3 7o,, 4 5 I C ) is 0 Yes 7~~~~~fJ\4 1 9~~~~~~~~~~ 239 ~~~~~~~~~4 ) 4 a380 37, 0/ JG3 Ltindblad Fi-. la. Earlie~t and Ttit --vi cycloi-.e occurrences f,"r the period 1886-1070. Numbers Within Iho,,eF -,re the month Hand date of earliest and later.'-. lar~dfa,'Is for the innicnted coastal -,epment. |JAN- x EARLIEST OCCURRENCE JAN. x o LATEST OCCURRENCE x- FEB. MAR-l t - ONLY ONE OCCURRENCE MAR. DURING PERIOD APR. MAY. _ JUN._ x -xxK-x X--x X-x X-xX % _x 0 5 10 '15 20 25 350 :35 40 45 50 55 COASTAL SECTION Fig. lb. Earliest and latest tropical cyclone occurrences for the period 1UG 6-197. Numbers along the abscissa are the coastal segment identifiers. 1886-1970. Numbers along the abscissa are the coastal. segrrment identifier,,,, 7. and latest tropical cyclone landfalls in each sector. The same informa- tion is presented graphically in Figure lb. Here it is seen that there are three coastal areas where storms oc- curred in February; these are segment numibers 24, 52 and 58. In fact, all three of these events were the result of a single tropical storm in 1952 that moved from the western Caribbean across southern Florida and then along the Atlantic Seaboard to New England. Although this storm has been identified as an early occurrence on Figures la and lb, it was actually a highly anomalous, off-season storm, and should not be seriously considered 'when assessing risks. Otherwise, it is noted that in general the Gulf of Mexico coastline is more vulnerable than the Atlantic coast to early-season cyclones. This, of course, is to be expected since the primary early-season hurri- cane genesis regions are the western Caribbean and the Gulf of Mexico. The location of the latest occurrences of late-season storms is shared by southwest Florida and the Cape Hatteras area. Other than this, late storms appear to be fairly well distributed along the Gulf of Mexico and Atlantic coastlines. Figures 2a and 2b show the frequency of occurrence of tropical cy- clones for each of the three categories for each coastal sector. The numn- bers are in percentage units and are the arithmetic average of actual storm occurrences over the period of record. As discussed in the preceed- ing section, these values may be regarded as an estimate of the probability of a cyclone landfall. One obvious feature of Figures 2a and 2b is the concentration of high likelihood of great hurricane landfalls along the Gold Coast of southeast- ern Florida as well as along most of the Texas coast. This histogram and table shows the probabili ty (percentage) that a tropical storm, hurricane, or great hurricane will occur in any one year in a 50 mile segment of the coastline. Figure A. identifies the numbered coastal segments. 20 - 1.5- * _ ~~~~~~~~~~~~LEGEND P,- ALL TROP CYCL P". ALL HURR 0M 4 COASTAL SECTOR �2 3 4 5 6 7 8 9 10 it12 13i4 151617I819 20 2.22 23 2425 2627 2829 ALL TROPICAL CYCLONES-9 12 13 12 18 21014 12 13 IS 21 15 13 21 19 it 16 19 20 12 9 12 1.2 21 19 18 1.6120 20 ALL HURRICANES 6877 9141 8 6 6 9 13 9613 14 76 7 68 64 5 913 1312116 I5 GRATHURIANS 54 44- - - 2- - - - -- - - - - 2- - S 4 2 - m - F - Fig. 2a. Frequency of tropical cyclones along the U.S. Gulf of Mexico coastl~ine. This histogram and table shows the probability (percentage) that a tropical storm, hurricane, or great hurricane will occur in any one year in a 50 mile segment of the coastline. Figure 1 identifies the numbered coastal segments. 20 - z w i5- *- r g S ALL TROP CYCL ~> tO-k ~ io g g - � ALL HURR. :IF Ig~~~~~~~~~~ | g g - WGREAT HURR. GREAT HURRICANES 5 -- - - 2 2 - 2 4 1 - - ~F.FnALL TROPICAL CYCLONES 117 4 51688n3 74 t8 922 4 lant ic6 c oa6 I l8i ALL HURRICANES 8 5 2=� ,. 28 2 2 u-li 6 6 7 6 -I- 4 6 5 GREATHURRICA NES 5- t - 2 12-21u 2 4 _ - - -I-I- - -I Fig. 2b. Frequency of tropical cyclones along the U. S. Atlantic coastline Fig.3 Number of TROPICAL CYCLONES reaching U.S. mainland E 1886- i970 Sector I 2 34 5 6 7 8 9 0 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 IAll Tropical Cyclones 8 10 11 10 15 17 12 10 11 15 18 13 11 18 16 9 14 16 17 10 8 10 10 18 16 15 14 17 171 IAII Hurricanes 7 6 6 8 12 10 75 5 8 11 8 5 11 12 6 5 6 5 7 5 3 4 8 11 11 10 14 131 [6reat Hurricanes 2 4 3 3 3 3 3 1 -2 3 1 - - 2 1 2 3 2 4 6 6 [Sector 30 31 32 33 34 3536 37 3839 4 42 43 44 45 46 47 48 49 50 51 5253 5455565758 IAII Tropical Cyclones 9 6 66 3 4 17 7 11II 6 12 15 8 2 2 3 1 1 1 9 5 18 5 - - 6 7 11 IAll Hurricanes 7 4 2 1 1 2 67 4 5 5 4 9 7 2 2 2 1 - 1 5565-- 3 5 41 |Great Hurricanes 4 - - - - 1 2 2 - 2 3 1 I I - I . Fig.4 Number of years between TROPICAL CYCLONE occurrences Average for the period i886-:1970 |Sector 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 291 IAll Tropical Cycloneslo 8 7 8 5 7 8 7 5 4 6 7 4 5 9 6 5 5 8 10 8 8 4 5 5 6 5 51 IAII Hurricanes 12 14 14 10 7 8 12 17 17 10 7 I0 17 7 7 14 17 14 17 12 17 28 21 10 7 7 8 6 61 1Great Hurricanes 42 21 28 28 28 28 28 85 - - 42 28 85 - - - - - - -85 42 85 42 28 42 21 14 141 rsector 3 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 IAll Tropical Cyclones 9 14 14 14 28 21 6 12 12 7 14 7 5 10 42 42 28 85 85 85 9 17 4 17 - -14 12 7 IAII Hurricanes 12 21 42 85 85 42 14 12 21 17 17 21 9 12 42 42 42 85 - 85 17 17 14 17 - - 28 17 21 |Great Hurricanes 21 - - - -85 85 - 42 42 -42 28 85 - 85 85 All TROPICAL CYCLONES (4OMPH or higher) All HURRICANES (74MPH or higher) GREAT HURRICANES (125 MPH or higher) Figure 3 summarizes the actual count of the tropical cyclone land- falls which affected each coastal sector. Finally, Figure 4 lists the average number of years between tropical cyclone occurrences. It is beyond the scope of this report to discuss any further the many details of the data contained herein. Certainly, some of the smaller- scale details must be considered cautiously in light of the nature of the data. However, it is hoped that this paper will serve as a useful start- ing point for the application of tropical cyclone summary data. ACKNOWLEDG3EMNT S The authors are indebted to Mr. Robert L. Carrodus of the National Hurricane Research Laboratory who prepared the figures, and to Mr. Charles J. Neumann, Spaceflight Meteorology Group, Miami, Florida, who assisted with the programming for the numerical computations. 12. APPENDIX Coastline Segment Locations The following latitude/longitude combinations comprise a list of the left endpoints of the coastline segments as referenced from an off- shore viewing position and as illustrated in Fig. la. The right end- point of any segment is the left endpoint of the next higher-numbered segment. There are two exceptions: segment no. 25 in extreme southern Florida; and segment no. 58, the northernmost segment. The right end- points for the exceptions are indicated in the listings below. Also, the cities identified below are only for the reader's con- venience as points of reference. Coastline Segment Locations Coastline Segment No. Left Endpoint Lat. Long. 1 25.95 97.15 (Brownsville) 2 26.75 97.35 3 27.57 97.22 4 28.23 96.62 5 28.67 95.80 6 29.13 95.02 (Galveston) 7 29.60 94.25 8 29.77 93.30 9 29.52 92.37 10 29.32 91.43 11 29.07 90�52 (New Orleans) 12 28.98 89.15 13 30.20 88.93 14 30.22 87.97 15 30.35 87.02 APPENDIX (cont'd) 13. Coastline Segment No. Left Endpoint Lat. Long. 16 30.28 86.05 (Panama City) 17 29.68 85.38 18 29.88 84.43 19 29.70 83.50 20 29.08 82.88 21 28.23 82.87 (Tampa) 22 27.42 82.68 23 26.67 82.25 24 25.97 81.77 25 25.12 81.13 ---- Right Endpoint: Lat. 25.32, Long. 80.25 26 24.53 81.82 (Key West) 27 24.77 80.93 28 25.32 80.25 29 26.13 80.03 30 27.00 80.05 31 27.73 80.38 (Vero Beach) 32 28.55 80.55 33 29.27 81.02 34 30.05 81.33 (Jacksonville) 35 30.90 81.42 36 31.68 81.12 (Savannah) 37 32.33 80.48 38 32.83 79.70 39 33.48 79.08 40 33.77 78.15 (Wilmington, N.C.) 41 34.43 77.53 42 34.60 76.53 43 35.23 75.53 44 36.05 75.67 (Norfolk) 45 36.85 75.97 46 37.63 75.60 47 38.35 75.07 48 39.15 74.70 49 39.83 74.08 50 40.58 73.63 51 40.80 72.57 52 41.15 71.55 (Nantucket) 53 41.25 69.95 54 42.08 69.90 55 42.72 70.62 56 43.52 70.32 (Portland) 57 43.91 69.32 58 44.25 68.25 ---- Right Endpoint: Lat. 44.80, Long. 66.90 i4. REFERENC ES Cry, George W., 1965: "Tropical Cyclones of the North Atlantic Ocean: Tracks and Frequencies of Hurricanes and Tropical Storms, 1871-1963", Technical Paper No. 55, Uo S. Weather Bureau, Washington, D. C., 148 pp. Hope, John R., and Neumann, Charles J., 1968: "Probability of Tropical Cyclone Induced Winds at Cape Kennedy", ESSA Technical Memorandum WBTM SOS - 1, U. S. Department of Commerce, Washington, D.C., 67 PP. ...., and .., 1969: " Climatology of Atlantic Tropical Cyclones by Two and One-Half Degree Latitude - Longitude Boxes", Technical Memorandum wBTM - SR - 44, U.S. Weather Bureau, Southern Region Headquarters, Fort Worth, Texas, 50 pp. .... ~and ...., 1970: "An Operational Technique for Relating the Movement of Existing Tropical Cyclones to Past Tracks", Monthly Weather Review, Vol. 98, No. 12, pp 925 - 933. Thom, H. C. S., 1960: "The Distribution of Annual Tropical Cyclone Fre- quency", Journal of Geophysical Research, Vol. 65, pp 213-222. (continued from inside front cover) NWS SR 55 Digitized Atlantic Tropical Cyclone Tracks. John R. Hope and Charles J. Neumann - February 1971 NWS SR 56 Memorable Hurricanes of the United States Since 1873. Arnold L. Sugg, Leonard G. Pardue and Robert L. Carrodus - April 1971 (COM-71-00610) NWS SR 57 Some Aspects of Probability of Precipitation Forecast Performance by WSFOs in the Southern Region - November 1969 Through October 1970. Allen D. Cummings - May 1971