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amd 0,7("w Coastal Zone 90-L -2 7 1970 Information Center U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration PRELIMINARY REVISED STANDARD PROJECT HURRICANE CRITERIA FOR THE ATLANTIC AND GULF COASTS OFTHE UNITED STATES MEMORANDUM HUR 7-120 Prepared by 14ydrome'teorol6gical granch ..Office of Hydrology r <3 National Weather Service QC Silver Spring, Md. 944 N38' IJune 1972 1972 Th is draft report gives some revisions to a study covering the same subject published in 1958 [1]. In the last two years effort has been directed towa rd providing more regional details in the analysis of the generalized meteorological parameters used to describehurricanes. Results of that study, to be completed in 1974, may-necessitate changes in standard project hurricane (SPH) criteria. Another draft study [31, giving similar meteorological criteria for probable maximum hurricane (PMH) wind fields, will also be effected. Studies now in progress are reevaluating these criteria with plans for a published report sometime in 1975. This report, based on ,these more detailed studies, will provide consistent SPH and- PMH wind fields. CONTENTS 1. Introduction ....................................................... I II. Interpretation of the SPH .......................................... 3 III. SPH parameters ................................................... 4 IV. Revisions to NHRP Report no. 33 .....* .............................. 5 V. Other SPH criteria, not revised .................................... 10 VI. Isovel wind field construction .................................... 10 References .............................................................. Tables Figures QN, <5- NJ jot. PRELIMINARY MEMORANDUM HUR 7-120 REVISED STANDARD PROJECT HURRICANE CRITERIA FOR THE ATLANTIC AND GULF COASTS OF THE UNITED STATES Hydrometeorological Branch Office of Hydrology NOAA, National Weather Service I. Introduction This memorandum covers revisions to Standard Project Hurricane (SPH) criteria given in National Hurricane Research Project Report No. 33 [1]. The need for these revisions was prompted by a comparison of the wind fields in well-developed hurricanes that occurred since 1956 with those used to develop the SPH in the original study. It is Believed the wind fields or average radial storm winds of NHRP No. 33 Should be stronger relative to the highest winds near the center of the storm. This is supported by the number of storms in recent years with winds that exceed those of NHRP No. 33.Figure 1 shows a comparison of the earlier radial wind profiles used in NHRP No. 33 with the profiles estimated in the more recent storms that bears outthis contention. In this figure both velocity and distance are drawn on a relative basis, i.e., by ratios of actual wind to maximum wind and ratios of distance from the storm center to radius of maximum wind. Memorandum HUR 7-84 [2] and several subsequent memoranda of that series provide revisions to NHRP No. 33 in zones B and C of the Gulf coast in order to better reflect the greater windspeeds of Hurricane Carla (1961) and others. Revisions of the present study are consistent with the revised values in zones B and C. While the revision of the relative wind fields provide the main motiva- tion for this work, other hurricane parameters were also updated, the most important being the Central Pressure Index (CPI). An important consideration in these revisions was to maintain consistency from zone to zone with a study giving meteorological characteristics of the probable maximum hurricane [3]. Criteria for the probable maximum hurricane (PMH) are the same meteoro- logical parameters, some with the same values and similar developmental techni- ques,as those of the SPH criteria. One reason why meteorological parameters, such as the CPI, need revision is that in the earlierstorms the lowest pressure was seldom measured and therefore had to be estimated by indirect methods (4]. Exceptions were those storms where the center passed over a land station or a ship at sea. In recent storms much more reliable central pressures are often obtained through dropsondes from airplanes into the hurricane center. The period of record for the revised SPH criteria includes all-relevant storms in the 72-year period from 1900 through 1971. Figure 2 shows revised values for maximum winds in the SPH along the Atlantic coast, wi.th moderate forward speeds and mean, radii of maximum winds, compared to the values previously published in NHRP No. 33. The increased winds up to about 35*N latitude are mainly due to lower CPI values in the revised analyses. The slightly lower winds farther north are due mainly to the adoption of a peripheral pressure that varies with latitude. The present study is meant to be an interim report, giving the major changes in SPH criteria from that in NHRP No. 33. Many references are 2 made to that report. The planned publication of revised SPH criteria will contain the necessary information so that these,references need not be made. II. Interpretation of the SPH The SPH is a hypothetical hurricane that is intended to represent the most severe combination of hurricane parameters that is "reasonably characteristid'of a specified geographic,region, excluding extremely rare combinations. The SPH is intended as a practicable expression.of the maximum degree of protection that should be sought as a general rule in the planning and design of coastal structures for communities where protection of human life and destruction of property is involved. The height of the storm- generated surge-is the critical factor. This is mainly dependent on the speed and direction of winds as a hurricane nears and enters the coast. Thus, the important product of the study is the hurricane wind field. There have been-liumerous inquiries indicating there are some misunder- standings concerning what the SPH criteria represent. NHRP No. 33 and the present revision show frequency analyses of the CPI for large zones along the gulf and Atlantic coasts The SPH uses the arbitrary 100-year return period of the CPI as a standard for comparison and consistency from zone to zone. However, use of 100-year return-period CPI values does not.imply, that the SPH has a 100-year return period for any place in a given zone, since other meteorological parameters are also important. Hence, the standard project hurricane has no,frequency assigned to it. The angle of storm approach to the coastline., the rate of travel, and.the radius of maximum wind are important meteorological considerations for determining the hurricane surge. Although a CPI with a 100-year return period may be read from figures in this report for any point along the coast, it does not. mean the value is expect ed to occur once in 100 years at that point. Because of the manner 3 in which the statistics of the CPI were developed (see pp. 3 and 4 in NHRP No. 33) the 100-year CPI at any point on the Atlantic coast, say x, must be interpreted as the CPI value which may be expected to occur once in 100 years, on the average, at some point in a 300 n. mi. zone centered at x. The smooth 100-year line which interpolates the CPI value from the mid-point of one zone to another is a convenience which insures a smooth regional pro- gression of the CPI values. Wind fields determined from NHRP No. 33 and this revision, represent 10-minute average speeds, standardized to a height of 30 feetabove the surface. The 10-minute average was adopted as a standard sustained wind. Storm surges cannot be generated from wind gusts. The 30-ft height above the surface is used to standardize observations from instruments at differing heights. III. SPH parameters The independent parameters used to develop the SPH criteria are: 1. Central Pressure Index (CPI). This is the lowest pressure at the storm center. It is an independent variable for determination of the maximum gradient windspeed (V gx). 2. Peripheral Pressure (p n). This is the sea-level pressure at the outer limits of the hurricane wind circulation. It should not be confused with the assymptotic pressure discussed in [3]. Revised maximum wind (Vx) values for this report (see Part IV, F) where p ndepends on latitude are shown in figure 2. 3. Radius of maximum wind (R). This is the radial distance from the hurricane center to the location of highest winds which usually occurs just outward the hurricane eye-wall cloud. 4 4. Forward speed (T). This is the rate of translation of the hurricane center from one geographical point.to another. IV.. Aevisions to NHRP Report No.33 .A. Added storm data Table A lists hurricanes with central pressures of less than 29.00 inches within each coastal zone for the 72-ydar period of record..(1900-1971). There are 32 more storms than shown for a similar list in NHRP No. 33. Table B lists all tropical storms which reached hurricane intensity at some time and moved through one or more of the zones during the 72-4year petiod of record (1900-1971). There is an increase of 50 in the number of storms over those in NHRP No. 33. B. Central Pressure Index (CPI) frequency analyses New frequency analyses, figures 3-9., were made for each zone using central pressures (p0) from table A. Changes in zone B were dictated pri- mar.ily by Hurricane,Camill.e.(1969,). C. Coastal profile of CPI. The variation of CPI along the coast was,-obtained by fitting smooth curves to the frequency analyses of the CPI values platted at the coastal center of each zone. Analysis of thediscrete 100-year return-period CPI values.resulted in smooth profiles along the Atlantic toast, figure 10, and Gulf coast, figure 11, and gravides the necessary continuity and con- sistency between the Atlantic and Gulf coasts. D. Nomogram for wind field profiles The generalized SPH wind field is paracentric. However, since it is symmetrical, a radial wind profile taken along the line of maximum wind (line M) may be used to reconstruct the entire wind field. This is done by rotating the profile about the storm center, adjusting the windspeed according to a simple cosine function. A wind profile nomogram, figure 12, was developed from hurricane wind patterns observed along the Atlantic and Gulf coasts through 1971. From the nomogram the radial wind profile for a given radius of maximum wind is defined by relative wind values read from isolines of radial distance (r.in n. mi.) from the storm center. The relative wind (V/V x is the ratio of the wind (V) at a radial distance W to the maximum wind (V along that radius. Profiles x are defined for all radii of maximum wind from 4 to 50 n. mi. This covers the SPH range from small (RS) to large (RL) radius. Relative wind (V/V X) profiles of some storms exceed those of the nomogram (see fig. 1). The percent of storms undercut is uncertain, but it is probably in the range of 10-15 percent. For instance in the period 1957 through 1971, 4 or 5 out of 32 hurricanes in the Gulf and Atlantic coastal,areas had some portion of their relative wind profile undercut. The storms that were partially undercut are: Carla (1961); Donna (1960); Ione (1955); Hazel (1954); Gracie (1959); and Camille (1969). This, however, does not mean that the actual SPH winds undercut all of these storms since the maximum wind (V x must also be considered. 6 Profiles from the nomogram, figure 12, provide higher windspeeds relative to the maximum wind (V than did NHRP No. 33 over the entire wind field in all zones. This is shown in figure 13, for zone C where the avewage increase along the profile is about 10 percent. The figure also shows profiles used in two earlier SPH wind field revisions (2, 51. The increase over NHRP No. 33 for other zones ranges to about 20 percent for mean (RM) and large (RL) radii of maximum winds. E. Maximum gradient windspeed (V gx The maximum gradient windspeed equation V gx . K'Vpn@ po -R (0.575T) from [4), provides a means for computing the maxi-im windspeed in a SPH whose other parameters are known. V gx is in mph when P n and p0 are in inches, R is in n. mi. and f is in hr-1. The coefficient (kyvaries with latitude [3] in the revised SPH criteria as opposed to a constant value of 73.0 used in NHRP No. 33. The peripheral pressure (p also varies with latitude. Figure 14 shows a plot of p n versus latitude in storms and the adopted curve. The central pressure (p 0), the radius of maximum wind (R), and storm speed (T) .are given In table 1. The values of V gx for mean (RM) and large (RL) radius of maximum wind were computed and also appear in table 1, after conversion to knots. F. Maximum windspeed (V x The maX4-um windspeed, in knots, adjusted to 30 feet above the water surface is defined by the equation: V - 0.865 V + 0.5T (2) x gx 7 where the gradient windspeed, V gX , from equation (1) is in knots and the forward speed, T, is in knots. V x was evaluated at 48 discrete geographical locations on the Atlantic and Gulf coasts using the two values of V (for RM and RL) for slow (ST), moderate (MT), and fast gx (HT) forward speeds. These values are listed in table 1. The same overwater friction coefficient, 0.865, for reducing the gradient wind to 30 feet above the.surface, was used in all zones. G. Wind fields Construction of isovel patterns involves rotation of the radial pro- file of windspeed about the hurricane center. If this is done by hand computation techniques, it is necessary to first sketch the wind profile along the radius of maximum wind, using figure 12. Under normal cir- cum tances this radius, or line of maximum winds, extends to the right of the direction of motion vector of the storm, making an angle of 115* with the direction vector. To get the windspeed, V... at any point x, a distance r from the center of the SPH, and that does not lie on line M, the expression V V (1-cose) (3) XP x 2 is used. x is the windspeed along the-profile on M at a distancer from the center and 6 is the angle between line M and radius vector through x. Although an angle of 115* between line M and the direction of storm motion is preferred, this angle may be any value from 15* to 165*. This agrees with the limits of rotation given in NHRP No. 33. 8 The wind direction is defined as the angle of incurvature over the wind field. The angle of incurvature is the angle between the wind direction and a tangent to a circle centered over the storm, and is consider ed to be positive when the wind has a component directed toward the storm center. The angle of incurvature criteria, the same as that shown in NHRP No. 33, is as follows. Radius Angle of incurvature 1. Center out to region of 00-100 maximum winds (R) 2. R out to 1.2 R, 100-250 3. 1.2 R and outward 250 Radial wind profiles for each zone from this study are compared with those in NHRP No. 33, in figures 15 through 21. The profile for zone C, figure 21, was used to construct a sample'wind field, figure 22. This is for mile 360 with a moderate forward speed and mean radius. H. Radius Of maximum winds (R)-and forward speed (T) Some of the values of the CPI (p .) were revised, and since R is some- what dependent on p0 (see figure 7 and 17, NHRP No.'33) the values of the three categories oi.R (small,'mean, and large)were accordingly revised. The new values in table 11&re only slightly different from'those in table 1 of NHRP No. 33. The values of the three categories 6f the forward speed (slow, moderate, and fast), read from figures 9 and 20, NHRP No. 33, resulted in slight differences from those originally published in table 1. 9 I. Frictional adjustment for windspeeds over land In NHRP No. 33, a constant factor of 0.70 was used for reducing over-water winds to over-land. For the present revision,,,we recommend a variation in this reduction factor with the windspeed. The basis for this is shown in figure 30 of HMR #32 [4]. For windspeeds less than 10 knots, use 0.40, for speeds greater than 73 knots use 0.78. In- terpolate linearly for intermediate speeds. These reduction factors for any over-water speed represent lower limiting values for the over- land windspeed at a point which is at least 10 miles inland along a trajectory starting at the coast. In other words, the reduction should be accomplished in about 10 miles over land. The speed-up when the trajectory leaves land to go back over water also occurs in about 10 miles. V.* Other SPH crtteria, not revised Other criteria for the SPH, such as adjustment for filling over land, and adjustment of windspeeds near shore, have not undergone revision. VIo Isovel wind field construction The procedure for constructing a revised SPH,wind field is illustrated by the following example for a location,along the Atlantic coast at 25.5*N. latitude. This example uses a mean radius of maximum wind (RM) and a moderate forward speed (MT). 1. From table 1, mean radius of maximum wind, (RM),,for the location is 8 n. mi., maximum windspeed (Vx) is 109 knots, and moderate forward speed (MT) is 10 knots. 10 2. Using figure 12, read off relative windspeeds (V/Vx) at various distances from the center for RM of 8 n. mi. For this example, the following table gives the V/V x and the actual wind, V, at the given Idistances. Distance from V/V x V (kts) center (n. mi.) 8 1.000 109 9 .995 108 12 .970 106 16 -916 100 20 .823 90 30 .698 76 40 .619 67 50 .559 61 60 0506 55 @80 .431' 47 100 .368 40 120 .317 35 150 .244 27 200 .158 17 3. For the values of V inside RM, read off relative'distances from the center and relative windspeeds from figure 23. Construct table, as in step 2. Relative distance Relative V V/V x 109 r = r/R x 8 from center (r/R) speed (V/V x x (knots) (n. mi.) .2 .025 3 1.6 .4 .117 13 3.2 .5 .227 25 4.0 .6 .450 49 4.8 .7 .735 80 5.6 .75 .835 91 6.0 .8 .900 98 6.4 .9 .970 106 7.2 4. Plot the values of steps 2 and 3, (V versus distance from centert r,) on graph paper, as in figures 24 1, upper right, and upper left. This ,gives the windspeed values for any point along the line of maximum winds. 5. On a large sheet (2'x2'), lay off a line (M), scaled with distance from a point designated as the center of the SPH. On this line, plot winds computed in steps 2 and 3 or interpolated from step 4*(See figure 24.) 6. To compute the windspeed V XP , at any point x in the SPH wind field that does not lie on line M, use the following equation: VxP = V-T/2 (1-cosB), where V is the windspeed along line M at the distance r from the center. To show, in general,'how the equation is used consider the point, X, 50 n. mi. from the storm center making an angle e of 60* with line M. The plot, figure 24, should be on a reasonably large graph paper in order to obtain deatils on winds within RM. We suggest a sheet about 2'2'. 12 a. On figure 24 read V, Atong line M, of 61 knots at a distance of 50 n. mi. from the center. b. Substituting in the equation gives 10 V 61- 2 (1-.5) 58.5 knots 7. To determine a particular isovel, say for 40 knots, the, following is suggested. a. Mark the 40-knot point on line M, using figure 24, upper right, to get distance from the center. b. Using the nomogram, figure 25, sketch in selected radial lines that indicate factors applied to forward speed (T) to find the 40-knot value at other points. These are tick marks .1,..2, etc., on figure 24, lower portion. Note that the 1.0 mark is.diametrically opposite to line M. c. To get the distance of the 40-knot valu6,from the center.,along the radial tick mark OA, multiply 10 (the value-of T) by OA to get, 4. Add 4 to 40 to get 44. d. From upper right profile of figure 24, find the,distance from center (along M), of the 44 knots and plot along line marked 0.4., This gives the location of the 40-knot wind on radial 0.4. Make similar computations for other radials to provide a smooth isovel around full circle of the pattern. Since the wind field is symmetrical about line M, half the pattern may be folded over to obtain the complete wind field. 13 e. For determining other isovels outside of R, follow the same procedure. f. For isovels inside of R, use the same procedure, utilizing the wind profile in the upper left corner of figure 24. A little experimenting will make the following evident. All isovels that have values larger than the differences between the maximum wind and the forward speed of the storm will be crescent or kidney-shaped. For the particular example above, where V - 109 and T = 10, all isovels with values x between 99 and 109 are crescent-ahaped. See example of the 100-knot isovel in figure 24. All other isovels are more or less circular. Alternate to detailed approach. Without sacrificing much accuracy, all nearly circular isovels may be drawn as true circles, provided the forward speed, T, is relatively low, say, 12 knots or less. To do this for the 40-knot isovel as an example, perform step 7a above. To find the 40-knot point on the ex- tension of M on the opposite side of the center use figure 24 again and find the distance from center to the 50 knot (40 + T = 50) value. Find the mid- point, on line M of the two points above, and using this as a center, draw a circle through the two points. This is the 40-knot isovel. Other isovels are determined in a similar manner. 14 REFERENCES 1. U. S. Weather Bureau,."Meteorological Considerations Pertinent to Standard Project Hurricane, Atlantic and Gulf Coasts of the United States," National Hurricane Research Project Report No. 33, 1958. 2. Memorandum HUR 7-84, Standard Project Hurricane Wind Field Patterns (revised) to replace existing patterns in NHRP Report No. 33,.for Zones B & C, August 17, 1965. 3. Memoranda HUR 7-97 and HUR 7-97A, "Interim Report - Meteorological Characteristics of the Probable Maximum Hurricane, Atlantic and Gulf Coasts of the United States," May 7, 1968, along with "Peripheral Pressures for Probable Maximum Hurricanes," December 3, 1968. 4. U. S. Weather Bureau, "Characteristics:of United States,Hurricanes' Pertinent to Levee Design for Lake Okeechobee, Florida," Hydrometeoro- logical Report No. 32, 1954. 5. MEMORANDUM HUR 7-94, Surface Winds (30 ft.).in Standard Project Hurricane Critical to Espiritu Santo Bay (Matagorda Bay, Texas), for Large Radius of Maximum Winds and For Fast, Moderate and Slow Forward Speed. 15 Table 1.--Standard project hurricane index characteristics Coastal Location CPI Radius of Max. Wind Forward Speed (T) Renregentative Maximum Wind Speeds (Knots) Zone Lat. (ON.) (inches (ab) (Nautical Miles) (Knots) Mean Radius of Max. Wind Large Radius of Max. Wind RS RM Rt ST MT HT V (RM) V (ST) V (14T) V (HT) V (RL) V,(ST) V (MT) V (HT) 9z x x x gx x x X 23 26.56 899.1 4 7 11 4 10 16 123 .109 112 115 123 108 111 114 24 26.61 901.1 4 8 11 4 10 16 122 108 ill 114 122 108 ill 114 25 26.68 903.5 4 8 12 4 10 16 121 107 110 113 121 106 109 112 25.5 26.73 905.2 4 8 13 4 10 17 120 106 109 112 119 105 108 112 26 26.77 906.5 4 9 14 4 11 17 119 105 109 112 119 105 108 ill 27 26.88 914.0 5 10 17 4 11 18 117 103 107 110 116 102 106 109 2 28 27.02 915.0 5 12 21 4 11 19 114 101 104 108 113 100 103 107 29 27.21 921.4 6 14 27 4 11 20 110 97 101 105 108 96 99 104 30 27.38 927.2 7 16 31 4 11 21 105 93 97 102 103 91 95 100 30.5 27.43 928.9 7 16 32 4 11 22 104 92 95 101 l0i 90 94 99 31 27.46 929.9 7 17 34 4 11 23 103 91 95 101 101 89 93 99 32 27.49 930.9 7 16 32 4 12 26 102 90 94 101 99 88 9i 99 3 33 27.48 930.6 7 16 31 4 13 30 100 89 93 102 98 87 92 100 34 27.46 929.9 6 15 30 5 15 34 100 89 94 103 97 87 92 101 35 27.44 929.2 6 15 29 5 17 39 98 88 94 105 96 86 92 103 35.5 27.44 929.2 6 15 29 5 18 41 98 87 93 105 .95 85 92 103 36 27.45 929.6 6 15 29 6 20 42 96 87 94 105 94 85 92' 103 37 27.49 930.9 7 16 31 8 23 45 94 85 93 104 91 83 91 102 4 38 27.55 933.0 7 17 34 10 26 47 90 83 91 102 88 81 89 99 39 27.63 935.7 7 18 38 12 29 49 87 81 90 100 84 78 87 97 40 27.72 938.7 8 19 43 14 32 51 83 79 88 98 79 76 85 40.5 27.77 940.4 8 20 46 15 34 51 81 78 87 96 77 74 83 92 41 27.82 942.1 8 21 50 16 35 52 79 76 86 94 74 72 82 90 42 27.92 945.5 9 23 56 17 36 53 75 73 83 91 69 68 78 86 43 28.03 949.2 9 26 64 17 37 53 71 70 80 88 64 64 74 82 44 28.15 953.3 10 28 72 17 38 153 67 66 77 84 59 59 70 77 45 28.26 956.7 11 31 80 17 39 53 63 63 74 81 53 55 66 73. Table l.-Continued Radius of Max. Wind Forward Speed (T) Representative Maximna Wind Speeds (Knots), Coastal Location Near City or CPI (Nautical Miles) (Knots) Mean Radius of Max. Wind . Large Radius of Max. Wind Zone Mile Let (*N) Other Landmark (In) (mb) RS RM RL ST MT HT V9x (RM) VX(ST) VX(MT) VX(HT) V,.(RL) V x(ST) V.0U) V x (UT) A 1335 24 26.65 902.5 4 7 11 4 16 17 123 107 110 114 121 107 110 113 1280 25 26.77 906.5 4 8 12 4 10 17 119 105 108 112 119 105 108 ill 1215 26 Marco, Fla. 26.91 911.3 4 9 14 4 11 17 117 103 106 109 116 102 106 109 1150 27 Lemon Bay, Fla. 27.04 915.7 5 9 16 4 11 is 114 101 104 108 113 100 103 107 1085 28 Dunedin, Fla. 27.16 919.7 5 10 18 4 11 19 ill 98 102 106 110 98 101 105 1025 29 Yankeetown, Fla. 27.24 922.5 5 11 19 4 11 20 110 97 100 105 109 96 99 104 960 30 Carbur, Fla. 27.31 924.8 6 12 21 4 11 21 107 95 98 103 106 94 97 102 B 900 29.7 Apalachicola, Fla. 27.34 925.8 6 12 22 4 11 28 107 94 98 106 106 93 97 105 840 31.5 Grayton, Beach, Fla. 27.36 926.5 6 12 22 4 11 28 105 93 97 105 104 92 95 104 780 31.6 Pensacola, Fla 27.36 926.5 6 12 22 4 11 28 105 93 97 105 104 92 95 204 720 30.3 Mobile, Ala. 27.36 926.5 6 12 22 4 11 28 106 94 97 106 105 93 96 105 660 29.1 New'Orleans, La. 27.36 926.5 6 12 22 4 11 28 107 94 98 106 105 93 97 105 600 29.3 Lake Barre, La. 27.36 926.5 6 12 22 4 11 28 107 94 98 106 105 93 97 105 540 29.5 March Island, La. 27.36 926.5 6 12 22 4 11 28 106 94 98 106 k05 -93 97 105 480 29.7 Grand Chenier,,La. 27.34 925.8 6 12 22 4 11 28 107 94 98 106 106 93 97 105 C 420 30 Part Arthur, Tex. 27.31 924.8 6 12 4 11 28 107 95 98 107 106 94 97 106 360 29 Galveston, Tex. 27.28 923.8 6 11 20 4 11 28 109 96 100 108 108 95 99 107 300 29 Bay City, Tex. 27.24 922.5 5 11 19 4 11 28 110 97 100 109 109 96 99 108 240 28 San Antonio Vay, Tex. 27.21 921.4 5 11 19 4 11 28 110 97 101 109* 109 97 100 109 180 27 Sarita, Tex. 27.15 919.4 5 10 18 4 11 28 112 99 102 ill Ill 98 101 110 120 26 Brownsville, Tex. 27.09 917.4 5 10 18 4 11 28 113 100 103 112 112 99 102. Ill CPI - central pressure index, estimated minimum pressure RS - representative small radius to region of maximum winds RM - representative mean radius to region of maximum winds RL - representative large radius to region of maximum winds ST - representative slow speed of translation of hurricane center MT - representative moderate speed of translation of hurricane center HT - representative high speed of translation of hurricane center T - speed of translation of hurricane center VgX . maximum theoretical gradient wind computed for each CPI with Pn-29.92 Vx estimated maximum 30-ft wind speed computed from V x -0.865 V gx + 0.5T Table A.--Hurricanes with central pressure index less than 29.00 inches (1900-1967) ranked by CPI Max. 30-ft wind max. 30-ft wind speed estimated speed estimated from analyses from analyses Date CH R vgx Lat. T of data Date CH R: IAt. T of data vgX (in.) (n.mi.) (kts) (deg. N.) (kts) (kts) (in.) (n.mi.) (kts) (deg. N.) (kts) (kts) ZONE 1 ZONE 3 Sept. 2, 1935 26.35 6 119 24.8 9 Sept. 27, 1958 27.66 25 01 34.0 18 Sept. 9, 1919 27.44 15 94 24.8 8 Oct. 15, 1954 27.66 36 80 33.0 26 82 Oct. 20, 1926 27.52 21 85 24.6 16 Sept. 21, 1938 27.86 50 72 33.7 - Sept. 10, 1960 27.55 22 - 24.5 9 Sept. 14, 1944 27.88 17 98 35.2 23 Sept. 18, 1926 27.59 24 96 25.8 17 Sept. 10, 1954 27.97 - - - - Sept. 16, 1928 27.62 53 102 26.7 13 Sept. 16,1933 28.25 42 73 35.2 9 Sept. 17, 1947 27.76 34 89 26.2 10 Aug. 28, 1958 28.26 - - 34.0 17 Sept. 4, 1933 27.98 29 88 26.9 11 Aug. 30, 1954 28.35 - - 33.4 - Sept. 15, 1945 28.09 24 86 25.5 10 Sept. 11, 1960 28.35 36 - 37.4 30 Sept. 8, 1965 28.11 22 - 25.2 11 Aug. 12, 1955 28.40 45 63 34.5 7 Sept. 28, 1929 28.15 28 85 24.9 10 Sept. 19, 1955 28451 so 68 35.0 9 Aug. 26, 1949 28.16 23 86 26.7 14 78 Sept. 18, 1936 28.53 34 55 35.2 16 Oct. 17. 1950 28.20 - - 25.8 6 Aug. 23, 1933 28.63 36 50 36.9 18 53 Oct. 11, 1909 28.30 22 82 24.5 10 Aug. 25, 1924 28.70 34 68 35 2 22 July 28, 1926 28.34 14 77 28.0 - Sept. 3, 1913 28.81 41 63 35:8 16; oo Sept. 22, 1948 28.41 16 74 26.8 11 Aug. 24o 1949 28.86 24 70 33.5 22 Sept. 27, 1964 28.57 - - 25.5 9 Dec. 2, 1925 28.95, 54 54 34.2 14 Nov. 4, 1935 28.73 - 69 - - Sept. 16, 1967 28.97 - - 36.6 9 Oct. 20, 1924 28.83 .25 54 25.8 6 Sept. 17, 1906 28.98 61 63 34.0 16 Sept. 11, 1903 28.84 43 66 25.8 8 Oct. 18, 1906. 28.84 35 58 26.9 6 Oct. 5, 1948 28.85 31 58 25.8 13 ZONE 4 June 17, 1906 28.91 26 63 26.9 12 Sept. 21, 1938 27.86 50 72 41.8 47 83 Sept. 11, 1954 27.97 - - 41.3 40 ZONE 2 Sept. 16, 1933 28.25 - 73 - - Sept. 14, 1944 28.31 48 62 41.4 30 83 Sept. 26, 1958 27.52 19 - 32.7 12 Sept. 11, 1960 28.35 - - 38.0 32 Oct. 15, 1954 27.66 36 80 32.0 82 Aug. 31, 1954 28.38 22 - .41.8 33 Sept. 29, 1959 28.05 10 - 32.0 12 100 Sept. 18, 1936 28.53 34 55 38.0 - July 28, 1926 28.34 14 77 28.4 8 Aug. 26, 1924 28.70 66 51 41.3 29 Aug. 30, 1954 28.35 - - - Aug. 29, 1958 28.73 - - 39.0 21 Aug. 12, 1955 28.40 45 63 32.5 7 Aug. 15, 1971 28.88 - - 42.5 11 75 Oct. 19, 1968 28.47 - - 31.0 17 Sept. 9, 1969 28.91 - - 43.8 40 Sept. 10, 1960 28.47 33 - 32.9 26 Sept. 19, 1955 28.51 50 68 32.8 10 Sept. 9, 1964 27.82 20 - 29.1 7 100 Oct. 15, 1947 28.59 13 63 32.1 17 Sept. 16, 1928 28.75 - - 29.5 - Aug. 11, 1940 28.78 27 67 32.0 9 90 Oct. 25, 1921 28.91 - - 29.0 10 Sept. 15, 1945 28.91 - - 29.0 - Aug. 28, 1911 28.92 27 63 32.1 8 Table A.--Continued Has. 30-ft wind speed estimates' from analyses Date CPI R vgx T Lat. Long. Date CPI R vgx T Lat. Long. of data (in.) (n.mi.) (kts) (kts) (deg.N.) (deg.W.) (in.) (n.mi.) (kts) (kts) (deg.N.) (dej.W.) Mts) ZONE A ZONE B Sept. 2, 1935 26.35 6 119 9 24.8 90.9 Aug. 17, 1969 26.61 15 ill - 28.6 88.5 130 'Sept. 9, 1919 27.44 15 94 8 24.6 82.9 Sept. 8, 1900 27.64 - 90 - 27.0 90.5 77 Oct. 20, 1926 27.52 21 97 16 23.8 81.3 Sept. 10, 1965 27.79 32 - 17 28.9 89.8 Sept. 10, 1960 27.55 20 - 9 25.5 81.5 Sept. 29, 1915 27.70 29 92 10 29.9 90.1 74 Sept..21, 1948 27.62 7 0 8 24.5 81.8 June 27, 1957 27.95 19 95 14 29.8 93.6 91 Oct. 17, 1910 27.80 16 73- 11 24.5 82.5 Sept. 14. 1919 28.00 - 20 26.9 90.2 Sept. 8, 1965 27.99 19 - 15 25.2 81.5 Sept. 20, 1926 28.20 17. 85 7 30.5 87.5 Oct. 18, 1944 28.02 27 91 13 24.6 82.8 July 21, 1909 28.31 19 86 - 26.8 91.0 Sept. 17. 1947 28.03 34 - - 26.4 81.3 Aug. 25, 1926 28.31 27 87 10 29.6 90.7 Sept. 18. 1926 28.05 24 - 17 26.5 81.0 Oct. 3, 1964 28.33 21 - 7 29.0 91.4 Sept. 28, 1929 28.15 28 - 10 24.8 81.1 July 5, 1916 28.38 50 70 25 30.7 8&0 Get. 25, 1921 28.29 18 70 10 28.1 82.8 July 31, 1936 28.46 19 70 9 30.5 86.5 Oct. 11, 1909 28.30 22 82 10 @24.3 81.7 Sept. 28. 1917 28.48 33 70 13 30.4 87.2 Sept. 16, 1928 28.30 53 - 2M 81.4 Sept. 27, 1906 28.50 73 72 16 30.6 88.5 Sept. 4, @950 28.30 - - - -29.1 83.1 June 16, 1934 28.52 37 70 16 29.9 91.7 Aug. 26, 1949 28.37 23 14 27.2 81.2 Sept. 19, 1947 28.54 33 63 16 29.9 90.1 83 Sept. 15. 1945 28.39 24 - 10 25.5 81.0 Aug. 14, 1901 28.72 33 72 14 29.9 90.1 Oct. 6. 1964 28.47 - - 15 24.0 83.0 Oct. 18, 1916 -28.76 19 70 21 30.4 87.2 Sept. 4, 1933 28.48 29 - 11 27.8 81.6 Aug. 7, 1940 , 28.76 11 62- 8 29.0 92.8 June 9. 1966 28.64 - - 9 30.0 84.3 Sept. 23, 1956 28.76 22 64 10 30.0 86.5 71 Oct. 18, 1968 28.70 - - 10 29.3 82.2 July 27, 1943 28.78 16 68 8 28.2 92.0 Oct. 19, 1924 28.70 19 - 8 25.0 83.0 Sept. 30, 1929 28.80 65 61 6 30.1 85.7 Nov. 4, 1935 28.73 - 69 - 25.0 81.0 Aug. 30, 1950 28.92 21 56 23 30.2 88.0 Sept. 11, 1903 28.84 43 66 7 27.0 81.5 Sept. 21, 1920 28.93 28 58 28 29.6 90.7 Oct. 18. 1906 28.84 35 58 6 25.0 81.0 Sept. @O, 1909 28.94 88 63 11 29.9 90.1 Oct. 5, 1948 28.85 31 58 13 24.0 81.2 Oct. 7, 1941 28.98 Is 68 11 29.9 BC7 Oct. 18, 1950 28.88 - - - 28.0 81.6 Sept. 15, 1960. 28.98 10 28.1 89.0 June 17, 1906 28.91 26 63 - 25.1 80.9 Oct. 4, 1966 28.94 - - 7 24.2 84.0 ZONE C Oct. 7, 1941 28.98 is 68 11 29.8 84.7 Sept. 20, 1967 27.26 25 118 8 26.0 97.1 95 Sept. 11, 1961 27.64 20 - 6 27.2 94.9 Sept. 8. 1900 27.64 14 90 10 29.2 95.9 77 Aug. 13, 1932 27.83 12 94 15 29.1 95.6 Legend Aug. 3. 1970 27.85 9 113 14 27.9 97.2 June 27, 1957 27.95 19 83 14 29.2 93.8 CPI - central pressure index Aug. 18, 1916 28.00 35 101 11 27.5 97.5 R - radius of maximum winds Sept. 14, 1919 28.00 - - 20 27.7 97.5 V gX - maximum gradient wind speed Sept. 5, 1933 28.02 20 91 8 25.9 97.5 T - forward speed of the storm Aug. 30, 1942 28.07 18 77 14 28.5 96.7 Aug. 16, 1915 28.14 32 72 11 29.8 95.0 63 June 22, 1921 28.17 17 84 11 29.7 95.4 July 21, 1909 28.31 19 86 12 29.0 96.0 Sept. 23, 1941 28.31 21 70 13 29.7 95.4 Aug. 27, 1945 28.57 is 77 4 29.0 96.2 June 28, 1929 28.62 13 71 15 28.5 96.5 Sept. 11, 1970 28.73 - - 11 23.9 96.3 Aug. 7, 1940 29.76 11 62 8 29.9 93.9 July 27, 1943 28.78 16 68 8 29.5 95.0 Aug. 4, 1933 28.80 25 66 10 25.9 97.5 Sept. 161, 1971 28.85 - - 15 29.4 93.2 Oct. 4. 1949 28.45 28 68 11 28.9 95.4 71 Sept. 10, 1971 28.91 - 5 28.5 96.0 80 Table B.-Average direction of center movement of all tropical storms in the zone which reached hurricane intensity at any time (1887-1971) Avg. Direction of Avg. direction of Avg. direction of Avg. direction of movement movement movement movement' within zone within zone within zone within zone Date (degrees to) Date (degrees to) Date (degrees to) Date (degrees to) ZONE 1 ZONE 2 Aug. 18, 1887 306 Aug. 6, 1928 - 318 Aug. 20, 1887 018 July 21, 1934 215 Aug. 15, 1888 302 Sept. 15, 1928 303 Aug. 22, 1887 353 Aug. 10, 1940 .304 Sept. 3, 1888 192 Sept. 25, 1929 235 Octi; 10, 1888 052 Aug. 2, 1940 234 Sept. 7, 1888 272 Aug. 28, 1932 297 Sept. 9, 1888 031 Sept. 18, 1941 029 Aug. 23, 1891 289 Sept. 5, 1932 348 Oct. 12, 1893 355 Oct. 8, 1941 107 Oct. 11, 1893 318 Oct. 4, 1933 056 Aug. 26. 1893 346 Get. 19, 1944 016 Aug. 26, 1893 323 Aug. 31, 1933 286 Sept. 25, 1894 Oil Aug. 1, 1944 350 Sept. 25, 1894 005 Sept. 2, 1933 299 Oct. 8, 1894 050 June 24, 1945 060 Oct. 20, 1895 030 July 29, 1933 293 Oct. 9, 1896 043 Sept. 16, 1945 016 Sept. 4, 1896 047 Sept. 6, 1934 328 Aug. 30, 1898 332 July 5, 1946 354 Oct. 9, 1896 049 Aug. 31, 1935 287 Oct. 1, 1898 300 Oct. 141, 1947 274 Aug. 1, 1898 290 Sept. 28, 1935 037 Oct. 30, 1899 000 Sept. 22, 19,48 058 Oct. 28, 1899 021 Nov. 3, 1935 237 Aug. 13, 1899 017 Sept. 5, 1950 345 Aug. 11, 1899 324 July 27, 1936 287 Oct. 20, 1904 318 May 16, 1951 019 Eli Aug. 9, 1901 296 Oct. 5, 1941 287 Sept. 13, 1904 307 Oct. 2. 1951 302 C) Aug. 10, 1903 291 Sept. 17, 1941 003 Oct. 19, 1906 213 Aug. 29. 1052 322 Sept. 11, 1903 293 Sept. 14, 1945 306 June 17, 1906 302 Sept. 21, 1953 068 Oct. 15, 1904 010 Sept. 12, 1946 025 July 28, 1908 001 Oct. 14, 1954, 094 June 16, 1906 032 Oct. 11, 1947 051 Oct. 18, 1910 015 Aug. 29, 1954 021 Oct. 17, 1906 036 Sept. 16, 1947 241 Aug. 26, 1911 295 Aug. 16, 1955 318 Sept. 30, 1908 002 Sept. 21, 1948 051 July 13, 1916 326 Aug. 11, 1955 348 July 27, 1908 336 Oct. 5, 1948 044 Oct. 25, 1921 075 Sept. 19, 1955 349 Oct. 11, 1909 052 Aug. 25, 1949 299 Sept. 29, 1920 043 Sept. 26, 1958 325 Nov. 21, 1912 034 Oct. 17, 1950 339 Sept. 22, 1920 314 Sept. 10, 1960 030 Nov. 15, 1916 062 Oct. 2, 1951 053 Sept. 16, 1924 060 Sept. 24, 1963 040 Sept. 7, 1919 270 May 17, 1951 125 Nov. 30, 1925 035 Sept. 9, 1964 218 Oct. 20, 1924 076 Oct. 24, 1952 052 July 26, 1926 335 June 5, 1968 343 Oct. 20, 1926 056 Sept. 10, 1960 315 Sept. 17, 1928 022 June 19, 1968 060 July 26, 1926 324 Aug. 27, 1964 345 Sept. 9, 1930 047 Aug. 10, 1968 034 Sept. 17, 1926 305 Sept. 8. 1965 270 Sept. 6, 1934 005 Oct. 19, 1968 043 Aug. 12, 1928 309 June 17, 1968 333 Aug. 8, 1969 033 Aug. 9. 1968 315 Table B.-Continued Avg. direction of Avg.-direction of Avg. direction of Avg. direction of Movement sovement t movemat within zone within some within zone within zone Date (degrees to) Date (degrees to) Date @(degrees to) Date ..(de$reds to) ZONE 3 ZONE 4 Aug. 20, 1887 047 July 21 1934 247 Oct. 20, 1887 017 Sept. 16, 2933 044 Oct. 20, 1887 035 Sept. 7, 1934 023 Aug. 21, 1888 068 Sept. 8, 1934 017 Oct. 11, less 038 Sept. 5. 1935 066 Sept. 10, 1888 *044 June 19, 1934 057 Nov. 25, 1888 024 Sept. 17, 1936 339 Oct. 11, 1888 045 Sept. 6. 1935 069 Sept. 24, 1889 057 Sept. 20. 1938 273 Now. 26, 1888 034 Sept. 18. 1936 0" Sept. 11, 1889 314 Aug. 31, 1940 025 Sept. 20, 1889 278 Sept. 24, 1936 015 July 8, legi 069 Aug. 16, 1940 037 Sept. 24, 1889 045 Sept. 21, 1938 007 Oct. 11, 1891 015 Sept. 22, 1941 029 Oct. 12, 1891 040 Sept. 1, 1440 027 Aug. 23, 1893 358 Oct. 8, 1941 108 July 8. 1891 066 Oct. 17; 1943 007 Oct. 4. 1893 104 Oct. 19, 1944 022 Aug. 23, 1893 003 Oct.-20, 1544 647' Oct. 13, 1893 006 Aug. 1, 1944 358 Oct. 9, 1894* 032 Aug. 2. 1944 061 Sept. 26, 1894 043 Sept. 13, 19" 008 Sept. 9, 1896 357 Sept. 14, 1944 033 Oct. 9, 1894 041 June 25. 1945 038 Aug. 19, 1899 064 June.26, 1945 046 Oct. 30, 1899 004 Sept. '17. 1945 013 June 29, 1902 098 Sept. 21,1950 042 Aug. 15, 1899 034 July 5, 19" 045 Oct. 12, 1902 066 Aug. 14, 1953 046 July 10, 1901 256 Oct. 9, 1946 086 Sept. 15, 1903 @332 Sept. 6. 1953 019 Oct. 10. 1903 022 Aug. 23, 1949 035 Oct. 11, 1903 059 Aug. 30, 1954 015 Sept. 15, 1903 347 Aug. 19, 1950 033 Sept. 14, 1904 039 Sept. 10, 1954 030 Sept. 14, 1904 329 Oct. 3, 1951 040 Sept. 15, 1912 078 Auj. lb, 1955 074 Sept 16, 1906 292 May 20, 1951 025 July 20, 1916 028 Sept. 270 1956 055 July 30, 1908 036 Aug. 13..1953 013 Sept..6, 1918 020 Aug. 29, 1958 045 Oct. 19, 1910 058 Sept. 27, 1953 058 Sept. 30, 1920 022 Sept. U, 1960 .028 Oct. 5, 1912 241 Oct. 15. 1954 002 Aug. 25, 1924 028 Sept. 18, 1962 046 Sept. 1, 1913 315 Aug. 30, 1954 029 Dec. 3, 1925 068 Oct. 21. 1968 032 July 19, 1916 012 Sept. 10, 1954 024 Aug. 23, 1927 034 Sept. 9, 1969 030 July 13, 2916 320 Aug. 11, 1955 012 Aug. 12. 1969 050 Sept. 22 1920 315 Sept. 18, 1955 015 Aug. 15, 1971 033 Sept. 30: 1920 025 Aug. 16, 1955 324 ,Oct. 23, 1923 348 Sept. 27.1956 050 Sept. 16, 1924 313 Aug. 28, 1958 045 Aug. 25, 1924 284 Sept. 27. 1958 010 Dec. 1, 1925 284 Sept. 11, 1960 028 Aug. 23j 1927 003 Sept. 28, 1962 036 Sept. 17, 1928 306 Sept. 20, 1963 320 Sept. 11. 1930 304 Sept. 16, 1967 018 Aug. 22, 1933 322 Aug. 11, 1968 067 Sept. 15, 1933 016 Oct. 20, 1968 043 Sept. 9. 1969 - 040 Sept. 30, 1971 315 Table B.-Continued Avg. direction of Avg. direction of Avg. direction of Avg. direction of- m am t Movement movement movement' ov n' within zone within zone within zone within zone Date (degrees to) Date (degrees to) Date (degrees to) Date (degrees to) ZONE A ZONE R Sept. 5, 1900 217 Sept. 2, 1935 335 Sept. 7, 1900 292 Sept. 29f 1929 000 Aug. 10, 1901 290 Nov. 4, 1935 270 Aug. 12, 1901 .325 Aug. 31, 1932 315 Sept. 11, 1903 292 Nov. 7. 1935 084 Oct. 9, 1902 020 Aug. 2. 1933 269 Sept. 17, 1904 10 July 28. 1936 303 Sept. 12, 1903 350 July 23, 1934 270 June 16, 1906 350 Aug. 2, 1938 250 Sept. 26, 1906 332 June 15. 1934 359 Oct. 16. 1906 038 Sept. 16, 1941 272 Aug. 10, 1911 318 Aug. 26, 1934 295 Oct. 10, 1909 020 Oct. 6, 1941. 320 Sept. 11, 1912 315 Sept. 4. 1935 000 'Oct. 17, 1910 002 Oct. 16. 1944 010 June 12_1912 050 Nov. 7, 1935 075 Aug. 9. 1911 325 June 23, 1945, 059 Sepit. 3, 1915 000 July 30, 1936 327 Sept. 11, 1912 294 Sept. 15, 1945 000 Sept. 28, i915 355 Aug. 4. 1938 296 Sept. 2, 1915 327 Oct. 7, 1946 010 Oct. 17, 1916 005 Oct. 6, 1941 000 Now. 15, 1916 055 Sept. 17, 1947 289 July 4. 1916 350 Aug. 18, 1942 304 Nov. 9, 1919 275 Aug. 18, 1947 276 Sept. 27, 1917 025 July 25, 1943 273 Sept. 29, 1920 065 Oct. 11, 1947 038 Aug. 6, 1918 328 Sept. 19, 1943 32 Octi 24, 1921 050 Oct. 4, 1948 040 Nov. 12, 1919 280 Sept. 18, 1947 303 Oct. 19, 1924 060 Sept. 20, 1948 010 Sept. 21, 1920 350 Aug. 22. 1947 315 Nov. 30. 1925 041 Aug. 26, 1949 325 Sept. 29, 1920 060 Sept. 3, 1948 020 July 28, 1926 311 Oct.. 20, 1950 030 Oct. 15. 1923 010 Oct. 18, 1950 211 Sept. 18, 1926 300 Sept. 2. 1950 018 Sept. 13. 1924 035 Aug. 29. 1950 005 Sept. 16, 1928 330 Oct. 18, 1950 338 Sept. 19, 1926 308 Sept. 25, 1953 041 Aug. 8, 1928 310 Oct. 1, 1951 090 Aug. 24, 1926 000 Sept. 13, 1960 000 Aug. 12, 1928 321 Sept. 10, 1960 330 Aug. 9, 1928 310 Oct. 3, 1964 .355 Sept. 27, 1929 315 Oct. 14, 1964 040 Aug. 13, 1928 344 Sept. 10, 11965 315 Sept. 7, 1930 047 Sept. 8, 1965 280 Aug. 17, 1969 340 Aug. 29, 1932 296 June 9. 1966 346 July 30, 1933 270 Oct. 4, 1966 080 ZONE C Sept. 1, 1933 284 June 4, 1968 030 Oct. 4, 1933 024 Oct. 18, 1968 053 Sept. 7, 1900 305 Aug. 17, 1936 236 Sept. 3, 1933 325 May 24, 1970 018 June 24, 1902 005 June 26, 1936 318 July 22, 1934 247 July 20, 1909 276 Aug. 14, 1938 340 Aug. 27, 1909 292 Aug. 27, 1938 270 Sept. 13, 1910 000 Aug. 6. 1938 307 June 11, 1912 018 Sept. 22, 1941 346 Oct. 15, 1912 319 Aug. 20, 1942 299 June 27, 1913 295 Aug. 29, 1942 313 Aug. 16, 1915 345 July 26, 1943 302 Aug. 18, 1916 290 Sept. 15. 1943 025 Aug. 6, 1918 325 Aug. 24, 1945 000 Nov. 13, 1919 270 Oct. 22, 1947 308 Sept. 6, 1921 320 Oct. 3, 1949 000 June 20, 1921 346 June 24, 1954 316 June 13, 1922 305 Sept. 4. 1955 280 June 28, 1929 320 June 27, 1957 003 Aug. 12, 1932 329 Sept. 11, 1961 .330 Aug. 3, 1933 255 Sept. 20, 1967 332 July 6, 1933 240 Aug. 3, 1970 203 Sept. 3, 1933 278 Sept. 11, 1970 270 July 24, 1934 270 Sept. 16, 1971 037 Aug. 26. 1934 212 Sept. 10, 1971 260 ad SPH tow 14* J _46- Vi, 04: &Qqj60) R=XG W@33 71 1) as L i :j AL _7 @j -7 1-L J- JL 41 4 R=zo -no I I Tip NMR[ Rot N&33@-A.,@, .3 7i4@@ 4 1;_1 :7 1 V --- Wind speed at point V --Maximum wind speed Rt Radi of maximum wind r-Radial distance of point Revised SPH from nomogram (Fig. 12) 74= @21 0 6 ",?c/&-t(V,,* R.Adil Disiay'lce Fig. 1---COMPARISON OF WIND PROFILES IN HURRICANES X Revi c4 SPH VX NMRP fyk N& .33 so 40- For mean radius of maximum wind(RM) and moderate storm speed(MT). 23 1 6 17 X15 I'l 30 31 31 55 SA- .36 57 -3-1 40 '+l 43 V. N. .3 Fig 2.--MAXIMUM WIND SPEED (V X ALONG ATLANTIC COA ST (Revis ed SPH and NHRP No. 33) 7-9 in A7 iL Ul: 10 20 30 40 Frequency per.-100 years -- VI+, ATIVE FREQUENCIES@OF,@@ Fig. 3. - - cumuL E CENTRAL FRESSURES(1900-1971) ZONE I 25 2.7 0.1 5 10 20 so .0 Frequency per 100 years Fig. 4-cumuLATIVE FRE QUENCIES OF HURRICANE CENTRAL PRESSURES (1900-197 1) ZONE 2 26 ;zq w (A iL127 J cr 26 0.1 1, 5 10 Lo 30 40 Frequency per 100 years o & F/4- Fig. 5, CUMULATIVE FREQUENCIES OF HURRICANE CENTRAL PRESSURES(1906m--1971)ZONE 3 27 29 r @J- @e 27 0. 10 20 so 40 Frequency per 100 years Fig. 6.--CUmULATIVE FREQUENCIES OF HURRICANE CENTRAL PRESSURES (1900-197 1) ZONE 4 28 LU w OL 2.7 u 2(0 0.1 1 5 10 ID 30 40 50 Frequency.per 100 years Fig 7.-- CUM UL,ATIVE FREQUENC.IES OF HURRI CANE CENTRAL PkESSURES(1900-1971)ZONE A 29 z LLI 5 10 20 so @o Frequency per 100 years Fig. 8.-- CUMULATIVE FREQUEliCIES OF HURRICANE CENTRAL PRESSURES (1900-197 1) ZONE B 30 7-9 28 H lu 27 2AG 10 10 30 40 Frequency per 100 years Fig. 9.--'CUMULATIVE FREQUENCIES'OF HURRICANE CENTRAL PRESSURES(1900-1971)ZONE C 31 ---------------- @r 44- --t-d %0I I a 41-4 op 29 -- - --------- T- -----= 4 - 4- j7 -4-A - 07@ L I J@o 7 171 71 1 17 it i I L 41 je 2.7 000 u f i4 26 -7- 1 -FIT 9-3 Z7 31 56 3q L &t Ctude (DeBroes N) 47 Fig. 10.--LATITUDINAL VARIATION OF AVERAGE FREQUENCY PER 100 YEARS OF CPI, ATLANTIC COAST ZONES . ..... . .. .. t7-- 7 I -,I @-7 29 oc.c FzREKc 46 p 0) M 7. 77 03 ZoNe 7:- 2ro 4: rooo 1200 0 200 400 'n ulfpwcoaLsL,(-n,-m0 '0'0 400 Dis-t&rpc;e Alo-9 Fig. ll.--GEOGRAPHICAL VARIATION OF AVERAGE FREQUENCY PER 100 YEARS OF CPI, GULF COAST ZONES Distance -F-rovn Center (-a. w%L.) 400 300 250 0 15,0 Azo /00 60 0 30 400 U4 300 -7 6 A -4 /1-0 loo 80 60 So 440 zo -16 Cl od O-Z 0-3 0-4- 0.5 0.6 0.7 0.8 0.9 /.o Wi-nal aa@to (V/vx) Fig. 12.--NOMOGRAM FOR DETERMINING WIND PROFILE HUR:7-84- Noymerarn i NHRP RPT K*3-:@ tA z 4 57 6 8 G1 lz 13 RactLa I D L@i a-n c e- Fig. 13.--COMPARISON OF RELATIVE WIND FIELD PROF ILES FOR ZONE C Q QL 30- 125 26' 27 ZL9 31 LtLt,2.' 35 37 39 41 43 49 Fig. 14.--VARIATION OF P WITH LATITUDE IN STORMS AND ADOPTED VARIATION -n A0 Ila too- - qo-- rim 70 V 64 .940 j HHRP FWr W3 30 FLS. 2-3, El For mean radius of maximum wind (RH) and moderate storm speed(mr). ,20 40 40 so 100 110 140 160 180 2.00 zzo Fig. 15.--COMPARISON OF WIND FIELD PROFILES FOR ZONE 1 36 7:: !.:1:. -1:71 60 j 40 310 Lat-30-514 ba For:mean.radjus of max@=sm wind(RK) an@ moderate storm sp@ed()@r). __j - ----- J- 0 20 40 60 80 /00 Mo 140 1 (66 too 200 120 240 A60 Ractiad Dis+.aviep- On. YnQ Fig. 16.@-COMPARISON OF WIND FIELD PROFILES-FOR ZONE 2 loco Co 70 Rp RP0633 F@2- 30 20 For mean rodiu: of maximza wind(XK) \tv and moderate 6 orm speed(Xr 20 40 60 80 100 1 160 1w 200 X@ft-' RaodLal. Dt,+=.6 (-n. -"U) Fig. 17.--COMPARISON OF WIND FIELD PROFILES FOR ZONE 3 37 q0 17 t -4 -7 r-SPH 7- 4D -a40 fig. as Lat. 46-5@ to 'For mean radius of maxim-m wind(RM) and moderate storm speed(MT). ZO 40 60 SID 100 /240 140 160 180 ZOO 120 246 266 Aso 3iz7- Radia I Dis+avica Oet. ynz.) Fig. 18.--COMPARISON OF WIND FIELD PROFILES FOR ZONE- 4 9 Ammmk $PH .(ft 5b NJM, Rrr Fis- 13 -1, M.Ull I 30 For mean radius of maximas wind(M) and moderate storm speed(MT). oil 40 so go /,00 110 140 160 180 2PO Z20 6". Fig. 19---COMPARISON OF WIND FIELD PROFILES FOR ZONE A 38 110 ss: T -T-77 -'7-' 7 7-- 71-7,-l p IRA J44 --4 30- 4-3 10 For mean radius of maximum wind( and moderate storm speed(Mr). 0 to 40 60 so /00 IAO /40 /60 ISO 200 220 Zo 260 260 3aa Distance (-et. vni) Fig. 20.--COMPARISON OF WIND FIELD PROFILES FOR ZONE B 70 060 7 Ql,l 70"s C, MUM2 20 10 E For mean radius of maximum wind(SH) and moderate storm speed(Kr). 4" 60 100 120 /4V 160 1" 2" 12.0 2000 R&AAi Distance (VI.ML), Fig. 2 -1.--COMPARISON OF WIND FIELD PROFILES FOR ZONE C 39 LL. 0 01@ Vol 60 50 30 20KTS 101P 0#41 Fig. 22.---!EXAMPLE OF REVISED SPH WIND FIELD, ZONE C Mean radius of maximum wind and moderate storm speed. 40 1.0 o.q 4:@ 14 4j cc o.3- 0.2 0.1 - 01 1 0-1 0-2- 0.3 0.4 0.6 0-6 0.7. 0.8 0.9 Relative RaAial Distance(r/R) Fig. 23.--VARIATION OF WINDSPEED (V/V x WITH RADIAL DISTANCE (r/R) WITHIN THE RADIUS OF MAXIMUM WIND ju V WIN01 FROFILr=. J:NsipF- RM 43 OurSIDE RM so XL 40 I I pal I 0 2- 6 8 -nJhL. 40 180 Ra4ial Distance 05 0.7 0.3 y 40AIft Ole 0,21 lirts. MS. Fig. 24.--EXAMLE OF WIND FIELD CONSTRUCTION 42 .8S .8 .7 .6 .5 .98 .3 1.00 .-rat- .95 .02 0 .7 .02. .6 .3 .2 .15 .7 Fig. 25 NGKOGRAM FOR WIND FIELD ASSYMETRY FACTOR Values are ratio of storm speed(T) to be subtracted from maximum wind profile. 43 3 6668 14102 5629