1931 Storm 1 – Revised 2012 25250 06/25/1931 M= 4 1 SNBR= 561 NOT NAMED XING=1 SSS=0 25250 06/24/1931 M= 5 1 SNBR= 561 NOT NAMED XING=1 SSS=0 ** * The 24th is new to HURDAT. 25252 06/24* 0 0 0 0* 0 0 0 0*180 870 30 0*186 869 35 0 25255 06/25*210 846 35 0*216 858 35 0*222 869 40 0*227 880 40 0 25255 06/25*192 868 40 0*198 869 45 0*205 870 45 0*213 878 40 0 *** *** ** *** *** ** *** *** ** *** *** 25260 06/26*232 889 40 0*235 895 40 0*239 903 40 0*244 914 40 0 25260 06/26*222 887 40 0*231 898 40 0*239 910 40 0*245 923 40 0 *** *** *** *** *** *** *** 25265 06/27*248 926 35 0*253 938 35 0*257 949 35 0*262 960 35 0 25265 06/27*250 938 40 0*255 950 40 0*260 960 40 0*264 968 40 0 *** *** ** *** *** ** *** *** ** *** *** ** 25270 06/28*267 967 35 0*270 972 35 0*274 977 35 0*278 982 30 0 25270 06/28*267 976 35 0*269 982 30 0*270 985 30 0*270 987 25 0 *** *** *** ** *** *** ** *** *** ** 25275 TS US landfall: 6/27/1931 - 22Z - 26.6N 97.3W – 40 kt Major track changes and minor intensity changes are implemented with this tropical storm. Evidence for these alterations comes from the Historical Weather Map Series, Monthly Weather Review, the COADS ship database, and the Original Monthly Records from NCDC, and Dunn and Miller (1960). June 24: HWM analyzes an open trough of low pressure over Central America, parts of the Yucatan Peninsula and the extreme western Caribbean Sea. HURDAT did not previously analyze the system on this day. Available observations from HWM and COADS indicate a closed circulation by 12Z near 18N, 87W. Ship highlights: No gales or low pressures. June 25: HWM analyzes a closed low of at most 1010 mb centered near 19N, 86.8W. HURDAT listed this as a tropical storm at 22.2N, 86.9W. The MWR Tracks for Centers of Cyclones showed a center near 22N, 87.5W. Ship highlights: 35 kt SE at 20.5N, 85.6W (MWR); 25 kt SE and 1002 mb at 12 UTC at 20.5N, 85.6W (MWR). No other gales or low pressures. June 26: HWM analyzes an elongated, closed low centered over land near 17N, 92W. HURDAT listed this as a tropical storm at 23.9N, 90.3W. The MWR Tracks for Centers of Cyclones showed a center near 24N, 91W. Ship highlights: No gales or low pressures. Regarding the intensity: "On the 25th, a depression was over the peninsula of Yucatan, that afterwards developed into a moderate tropical disturbance. On the daily weather map for June 26 it is stated: 'A disturbance of moderate intensity is apparently central in the south-central portion of the Gulf of Mexico.' On the 27th the center of this disturbance was about 100 miles east-northeast of Brownsville, Tex., and on the 28th over the coast of western Texas" (MWR). June 27: HWM analyzes a closed low of at most 1010 mb centered near 25N, 95.5W. HURDAT listed this as a tropical storm at 25.7N, 94.9W. The MWR Tracks for Centers of Cyclones shows a center near 26N, 95.5W. Ship/Land highlights: 35 kt NE (max w/1-min) with 1010 mb at 15Z at Corpus Christi (OMR); 1006 mb at 2230 UTC at Brownsville, TX (OMR); 1009 mb (min p) at 23Z at Corpus Christi (OMR). Regarding the intensity: Corpus Christi, TX: "The outstanding feature of the month was the small and moderate tropical disturbance that passed inland near this coast on the 27th. Rainfall was excessive on that date, under the tropical storm influence. During the 24-hour period total rainfall was 8.04 inches. The excessive rainfall caused considerable damage to streets and roads in this city. In many parts of the city of Corpus Christi water was in the streets to a depth of two to three feet" (OMR). Corpus Christi: 1009 mb at 23 UTC (OMR). June 28: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 27.4N, 97.7W. The MWR Tracks for Centers of Cyclones shows a center near 28N, 98.5W with a 1009 mb pressure. Ship/Land highlights: No gales or low pressures. “Tropical Cyclones of Texas, Jun 28, Lower Coast, Minor [“Minor” refers to less than 64 kt], Heavy Rains” (Dunn and Miller). HURDAT originally started this at 00Z on 25 June as a 35 kt tropical storm, but observations from HWM and COADS indicate a closed circulation by 12Z on the 24th, and a tropical depression is analyzed to have formed at 12Z on 24 June in the western Caribbean just east of the Yucatan Peninsula. Several ships on the 25th indicate that the original HURDAT position around 12Z on the 25th was too far north. A slow northward motion is analyzed from the 24th to the 25th instead of the west-northwestward motion shown in HURDAT originally early on the 25th. Major southwestward track changes are implemented on the 25th at 00 and 06Z. At 12Z on the 25th, a ship in the periphery observed a 1002 mb pressure simultaneously with 25 kt winds. The ship experienced maximum winds of 35 kt. The ship was located 80 nmi east of the analyzed position at the time of the 1002 mb observation. A central pressure of less than 1002 mb yields winds of at least 43 kt according to the Brown et al. southern pressure-wind relationship, and 45 kt is chosen for 12Z on the 25th (up from 40 kt originally). The center passed near Cozumel on the 25th and is analyzed to have made landfall near Playa del Carmen, Mexico around 13Z on the 25th as a 45 kt tropical storm. The peak intensity for the lifetime of this cyclone is analyzed to be 45 kt for the 12 hours just prior to the landfall in the Yucatan Peninsula. The previous HURDAT peak intensity was 40 kt from 12Z on the 25th to 18Z on the 26th. This intensity increase is based on the fact that the previous HURDAT did not show any weakening over land. Perhaps this is because the original track did not show a landfall in the Yucatan Peninsula and kept the system over water. The cyclone was over the Yucatan Peninsula from 13Z to 20Z on the 25th before moving into the Gulf of Mexico with an analyzed intensity of 40 kt (no change to the HURDAT intensity at 18Z on the 15th or 00Z on the 16th). Southward track adjustments of around 1.5 degrees are analyzed for 12 and 18Z on the 25th. All track changes for the remainder of the cyclone’s lifetime are minor changes. The cyclone moved west-northwestward in the southwestern Gulf of Mexico and made landfall on the south Texas coast around 22Z on 27 June at 26.6N, 97.3W as a 40 kt tropical storm. HURDAT previously showed a 35 kt intensity at the point before landfall, and this was increased to 40 kt. The highest observed wind from a land station was a fastest mile wind of 35 kt at Corpus Christi (34 kt after converting to a 10m 1-min wind). The lowest observed pressure from a land station was 1006 mb at Brownsville. The basis for the 40 kt landfall intensity is to choose the intensity 5 kt above the highest observed windspeed in the absence of a central pressure value to account for subsampling. The revised track shows landfall between Corpus Christi and Brownsville, but closer to Brownsville than in the original HURDAT. After landfall, the cyclone is analyzed to have weakened to a tropical depression at 06Z on 28 June (12 hours earlier than shown in HURDAT originally). No change is made to the timing of dissipation, but the position at the final point at 18Z on the 28th is adjusted to 27.0N, 98.7W as a 25 kt tropical depression. ******************************************************************************* 1931 Storm 2 – Revised 2012 25280 07/11/1931 M= 7 2 SNBR= 562 NOT NAMED XING=1 SSS=0 25285 07/11* 0 0 0 0*163 820 35 0*167 838 35 0*170 848 35 0 25285 07/11* 0 0 0 0*157 823 30 0*160 830 30 0*165 840 30 0 *** *** ** *** *** ** *** *** ** 25290 07/12*174 858 40 0*178 868 40 0*182 877 40 0*186 882 35 0 25290 07/12*170 850 30 0*175 860 30 0*180 870 30 0*185 880 30 0 *** *** ** *** *** ** *** *** ** *** *** ** 25295 07/13*191 887 35 0*198 892 35 0*206 897 35 0*214 901 35 0 25295 07/13*190 888 30 0*195 895 30 0*200 900 35 0*208 903 40 0 *** *** ** *** *** ** *** *** *** *** ** 25300 07/14*224 904 40 0*236 905 45 0*248 906 50 0*260 907 50 0 25300 07/14*220 904 45 0*235 905 50 0*248 906 55 0*260 907 60 0 *** ** *** ** ** ** 25305 07/15*271 908 50 0*281 909 50 0*290 911 45 0*298 913 40 0 25305 07/15*272 908 60 0*284 909 55 0*296 911 45 1000*304 913 40 0 *** ** *** ** *** *** 25310 07/16*306 916 35 0*315 921 30 0*325 926 25 0*333 931 25 0 25310 07/16*310 917 35 0*316 923 30 0*322 930 25 0*331 938 25 0 *** *** *** *** *** *** *** *** 25315 07/17*342 936 25 0*353 946 20 0*363 956 20 0*373 967 20 0 25315 07/17*342 947 25 0*353 957 20 0* 0 0 0 0* 0 0 0 0 *** *** *** *** ** *** *** ** 25320 TS US landfall: 7/15/1931 – 10Z – 29.2N, 91.0W – 50 kt Minor track changes and minor intensity changes are analyzed for this tropical storm. Major changes are made to the timing of when tropical storm intensity was first attained. Evidence for these alterations comes from the Historical Weather Maps Series, the COADS ships database, Monthly Weather Review, the Original Monthly Records from NCDC, and Dunn and Miller (1960). July 10: HWM analyzes a trough of low pressure in the western Caribbean Sea near Honduras. HURDAT did not previously analyze the system on this day. Although available observations including a west wind at 12Z at Cabo Gracias indicates the possibility of a closed circulation on the 10th, the west wind may have more like been a land breeze. Ship highlights: No gales or low pressures. Land highlights: 5 kt WSW and 1005 mb at 12 UTC at Bluefields, Nicaragua at 12.0N, 83.8W (HWM). No gales. No other low pressures. July 11: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 22.2N, 86.9W. Ship highlights: No gales or low pressures. July 12: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 18.2N, 87.7W. Ship highlights: No gales or low pressures. July 13: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 20.6N, 89.7W. The MWR Tracks for Centers of Cyclones shows a center near 21N, 89.8W with a 1009 mb pressure. Ship highlights: 35 kt SE and 1010 mb at 12 UTC at 18.0N, 86.9W (COA). No other gales. No low pressures. July 14: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 24.8N, 90.6W. The MWR Tracks for Centers of Cyclones shows a center near 24.8N, 91W with a 1008 mb pressure. Ship highlights: 60 kt ESE and 1006 mb at 2130 UTC at 27.6N, 90.6W (MWR); 50 kt SE and 1006 mb at 23 UTC at 27.6N, 90.6W (MWR); 2 observations of 35 kt ESE and SE at 18 and 22 UTC at 27.5N, 90.5W (COA). No other gales. No low pressures. Regarding the intensity: "A disturbance resembling in some of its characters a mild tropical cyclone originated in the western Gulf of Mexico on the 14th and caused winds of force 8 to 11 (35 to 60 kt) near the Louisiana coast as it progressed northeastward on the 14th and 15th" (MWR). The account of the W.C. Teagle: "... encountered this disturbance on the afternoon of the 14th, about latitude 28N, longitude 91W. The barometer fell rather sharply about two-tenths of an inch, reaching the lowest point at 4:30 pm, when the wind was ESE, force 11 (60 kt), with driving rain squalls and the air full of spray. At 6 pm, the wind was SE, force 10 (50 kt), with barometer pumping between 1006 and 1008 mb. Southeast gale continued throughout most of the night of the 14th-15th, but the wind changed to south by 7 am (15th) and diminished to force 6 (25 kt)" (MWR). July 15: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 29.0N, 91.1W. The MWR Tracks for Centers of Cyclones shows a center near 28.8N, 91.5W with a 1008 mb pressure. Ship highlights: 50 kt SE and 1006 mb at 00 UTC at 27.7N, 90.7W (COA); 50 kt SE at 02 UTC at 27.5N, 90.5W (COA); 45 kt SSE at 06 UTC at 27.5N, 90.5W (COA); 35 kt SSE at 10 UTC at 27.0N, 89.0W (COA). No other gales. No low pressures. Land highlights: 34 kt NW at Austin, TX at 30.3N, 97.8W (MWR); 1001 mb (min p) at 13Z at Morgan City, LA (29.7N, 91.2W) (OMR). No other gales. No other low pressures. Port Arthur, TX: 1008 mb at 23 UTC (OMR). Galveston, TX: 1009 mb at 23 UTC (OMR). New Orleans, LA: 1007 mb at 2130 UTC (OMR). “Tropical cyclones of Louisiana, July 14-15, Minor [“Minor” – Refers to winds less than 64 kt]” (Dunn and Miller). July 16: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical depression at 32.5N, 92.6W. The MWR Tracks for Centers of Cyclones shows a center in Louisiana near 32N, 92.5W with a 1010 mb pressure. Ship/Land highlights: No gales or low pressures. July 17: HWM does not analyze a closed low on this day. HURDAT listed this as a 20 kt tropical depression at 36.3N, 95.6W. The MWR Tracks for Centers of Cyclones shows a center in Oklahoma near 36.5N, 96W with a 1012 mb pressure. Ship/Land highlights: No gales or low pressures. A tropical depression is analyzed to have formed in the western Caribbean Sea on 10 July at 00Z (genesis is indicted 30 hours earlier than originally) with a position of 15.5N, 81.1W. HURDAT originally started this system as a 35 kt tropical storm at 06Z on 11 July at 16.3N, 82.0W. The revised positions on the 11th are slightly south the original positions. The cyclone is analyzed to have made landfall on the Yucatan Peninsula of Mexico just north of its border with Belize around 17Z on 12 July as a tropical depression instead of a tropical storm as indicated in HURDAT originally. This downgrade is due to sufficient observational coverage, which indicates a weaker cyclone. It is analyzed that the 30 kt tropical depression strengthened to a 40 kt tropical storm while over land – first attaining tropical storm strength around 12Z on 13 July (more than two days later than originally). The strengthening over land is analyzed because observations near the outer periphery of the circulation confirmed that winds were stronger on the 13th compared with the weak winds of the previous days. The highest wind on the 13th was a 35 kt ship observation about 240 nmi east-southeast of the center. The cyclone was over land until the 13th around 19Z before emerging into the Gulf of Mexico and turning northward. No significant track changes were made on the 14th. Late on the 14th, a ship encountered maximum winds of 60 kt from the ESE simultaneous with its minimum pressure of 1006 mb. Based on this ship, a 60 kt intensity is analyzed from 18Z on the 14th to 00Z on the 15th though it is possible that the system briefly reached hurricane intensity. The cyclone is analyzed to have made landfall in Louisiana around 10Z on the 15th at 29.2N, 91.0W as a 50 kt tropical storm. The highest available wind observation from a coastal station is 35 kt from the south around or slightly before 1230Z at Port Eads, LA. The lowest available pressure observation is 1001 mb with 10 kt W winds at Morgan City, LA at 13Z on the 15th. At 12Z on the 15th, HWM indicates that Morgan City recorded calm just before the 13Z 1001 mb pressure observation found in the OMR. The 12Z position on the 15th is analyzed at 29.6N, 91.1W based on the Morgan City data. A central pressure of 1000 mb is added into HURDAT at 12Z on the 15th based on the Morgan City data. The central pressure at the 10Z landfall was likely lower, and the 50 kt landfall intensity was chosen based on observations from Morgan City as well as several ship observations prior to landfall (a 50 kt intensity at landfall corresponds to a 996 mb central pressure according to the Brown et al. north of 25N pressure-wind relationship). It makes sense that the central pressure was around 996 mb at landfall if it was 1000 mb a few hours after landfall. The 45 kt intensity in HURDAT at 12Z on the 15th is not changed. It is of note that the 34 kt NW winds in Austin on the 15th were likely not part of this cyclone but were a separate system. After landfall, the cyclone continued inland and moved north-northwestward, weakening to a tropical depression at 06Z on the 16th while over Louisiana. No intensity changes were made from 12Z on the 15th through 06Z on the 17th and track changes were generally within a degree. The depression is analyzed to have dissipated after 06Z on the 17th (12 hours earlier than originally). It is of note that the cyclone had an unusual structure during and after landfall with strong (but not quite tropical storm strength) winds and significant rain well to its southeast over Mississippi and Alabama. It is possible that it had subtropical cyclone characteristics. ******************************************************************************* 1931 Storm 3 – Revised 2012 25325 08/10/1931 M= 9 3 SNBR= 563 NOT NAMED XING=0 SSS=0 25325 08/10/1931 M=10 3 SNBR= 563 NOT NAMED XING=0 SSS=0 ** 25330 08/10* 0 0 0 0* 0 0 0 0* 0 0 0 0*143 585 35 0 25330 08/10* 0 0 0 0* 0 0 0 0* 0 0 0 0*135 610 30 0 *** *** ** 25335 08/11*143 628 40 0*144 645 40 0*147 663 40 0*149 670 40 0 25335 08/11*145 629 30 0*152 646 35 0*157 660 40 0*160 672 40 0 *** *** ** *** *** ** *** *** *** *** 25340 08/12*152 678 45 0*154 688 45 0*155 699 45 0*154 712 50 0 25340 08/12*160 685 45 0*160 698 45 0*160 710 45 0*160 721 50 0 *** *** *** *** *** *** *** 25345 08/13*154 726 50 0*155 743 50 0*156 760 50 0*156 770 50 0 25345 08/13*160 732 50 0*160 743 50 0*160 755 50 0*160 768 50 0 *** *** *** *** *** *** *** 25350 08/14*156 780 50 0*156 794 50 0*156 808 50 0*156 818 50 0 25350 08/14*161 783 50 0*162 798 50 0*163 813 50 0*164 828 50 0 *** *** *** *** *** *** *** *** 25355 08/15*157 828 50 0*160 845 45 0*164 860 45 0*166 868 45 0 25355 08/15*166 843 50 0*168 858 45 0*170 870 45 0*172 880 45 0 *** *** *** *** *** *** *** *** 25360 08/16*168 875 40 0*170 882 40 0*172 888 35 0*175 895 35 0 25360 08/16*174 888 40 0*176 894 35 0*178 900 35 0*180 906 30 0 *** *** *** *** ** *** *** *** *** ** 25365 08/17*179 902 35 0*184 913 40 0*189 926 40 0*192 937 40 0 25365 08/17*183 912 30 0*186 919 35 0*189 926 50 0*191 933 50 0 *** *** ** *** *** ** ** *** *** ** 25370 08/18*194 946 40 0*195 954 40 0*196 963 35 0*197 972 25 0 25370 08/18*193 942 50 0*195 952 50 0*196 963 50 0*197 972 35 0 *** *** ** *** ** ** The 19th is new to HURDAT. 25372 08/19*198 980 25 0* 0 0 0 0* 0 0 0 0* 0 0 0 0 25375 TS Major track changes and minor intensity changes are implemented with this tropical storm. Evidence for these alterations comes from the Historical Weather Maps Series, the COADS ships database, and Monthly Weather Review, the Original Monthly Records from NCDC, and newspaper reports from The Antigua Magnet provided by Mike Chenoweth. August 10: HWM does not analyze a closed low on this day. HURDAT previously did not list this system until 18 UTC, as a tropical storm at 14.3N, 58.5W. Ship/Land highlights: No gales or low pressures. Regarding the intensity: "The following Monday (the 10th), when the barometer fell about two-tenths, there was apprehension of bad weather taking the island in its grip. No disturbance developed, however" (The Antigua Magnet, Saturday Aug. 22 1931). August 11: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 14.7N, 66.3W. The MWR Tracks for Centers of Cyclones shows a center near 14N, 64W. Ship highlights: 35 kt W at 00 UTC at 21.5N, 61.5W (COA). No other gales. No low pressures. Land highlights: No gales or low pressures. August 12: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 15.5N, 69.9W. The MWR Tracks for Centers of Cyclones shows a center near 14.5N, 70.5W. Ship/Land highlights: No gales or low pressures. August 13: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 15.6N, 76.0W. The MWR Tracks for Centers of Cyclones shows a center near 15N, 78W. Ship highlights: 45 kt NE and 1002 mb at 12 UTC at 16.3N, 75.4W (HWM); 40 kt E and 1012 mb at 12 UTC at 19.4N, 76.0W (HWM). No other gales or low pressures. Land highlights: No gales or low pressures. August 14: HWM analyzes a trough of low pressure in the southwest Caribbean Sea. HURDAT listed this as a tropical storm near 15.6N, 80.8W. The MWR Tracks for Centers of Cyclones shows a center near 15.5N, 82W. Ship highlights: 35 kt E and 1012 mb at 12 UTC at 15.0N, 76.3W (COA); 20 kt NE and 1002 mb at 12 UTC at 12.1N, 76.0W (COA); 40 kt E and 1011 mb at 09 UTC at 15.3N, 76.2W (MWR). No other gales or low pressures. Land highlights: No gales or low pressures. August 15: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 16.4N, 86.0W. The MWR Tracks for Centers of Cyclones shows a center near 16.8N, 86.5W. Ship/Land highlights: No gales or low pressures. Swan Island: 15 kt SE and 1006 mb (not minimum) at 12 UTC (HWM/OMR). August 16: HWM analyzes a trough of low pressures near the Yucatan Peninsula of Mexico. HURDAT listed this as a tropical storm at 17.2N, 88.8W. The MWR Tracks for Centers of Cyclones shows a center near 17.8N, 89.3W. Ship/Land highlights: No gales or low pressures. Regarding the track/intensity: "The disturbance crossed the full length of the Caribbean from east to west, moved into Yucatan on the 16th, and passed near Frontera, Mexico, on the next day when the Honduran steamship Morazan, lying in port at Frontera, experienced a gale of force 9 (40 kt), together with a wind change characteristic of the central area of a tropical disturbance" (MWR). August 17: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 18.9N, 92.6W. The MWR Tracks for Centers of Cyclones shows a center near 19N, 92.5W. Ship highlights: 35 kt NW and 1007 mb at 05 UTC at 18.5N, 92.6W (MWR); 40 kt NW (no time) in the vicinity of 18.5N, 92.6W (MWR); 45 kt SW and 1002 mb at 18 UTC at 18.7N, 92.7W (COA); S wind (no time) (MWR). No other gales or low pressures. Land highlights: No gales or low pressures. August 18: HWM analyzes a slight trough in the extreme western Gulf of Mexico. HURDAT listed this as a tropical storm at 19.6N, 96.3W. Ship highlights: S wind and 1005 mb at 00 UTC at 18.5N, 92.7W (COA). No other gales. No other low pressures. Land highlights: No gales or low pressures. August 19: HWM shows no features of interest in the western Gulf or over Mexico. HURDAT did not previously list this system on this day. Ship/Land highlights: None. HURDAT originally indicated that a 35 kt tropical storm developed at 18Z on 10 August at 14.3N, 58.5W. Observations from the Lesser Antilles indicate a closed circulation began about at that time and no change is made to the genesis timing. The eastern Atlantic Ocean was searched for observations back to 5 August. Although this tropical cyclone may have formed several days prior to 10 August, observations do not confirm a closed circulation prior to that date. A major westward track adjustment is implemented at 18Z on the 10th - observations on the 10th and 11th of August indicate that the position at 18Z on the 10th was about three degrees west-southwest of the original HURDAT position at that time. The system is started as a 30 kt depression (originally begun as a 35 kt tropical storm) and development into a 35 kt tropical storm now shown at 06Z on the 11th. All track changes from 11 August to dissipation are minor track changes (less than two degrees). The cyclone continued westward in the Caribbean Sea and is analyzed to have strengthened to a tropical storm by 06Z on the 11th (12 hours later than originally), and there were several 30 kt ship observations on the 11th. On 13 August, with the cyclone moving westward in the central Caribbean, a ship observation of 45 kt with 1002 mb was instrumental in the analysis for that day. A peripheral pressure of 1002 mb yields a wind speed of greater than 43 kt according to the Brown et al. southern pressure-wind relationship. The 50 kt intensity in HURDAT was not changed, and the position at 12Z was moved half a degree northeast of the previous HURDAT position to show a position closer to that ship observation. The cyclone made landfall around 20Z on 15 August a short distance south of Belize City, Belize as a 45 kt tropical storm. No intensity changes are made to HURDAT from 12Z on the 11th to 00Z on the 16th. The 45 kt landfall intensity is brought down to 35 kt by 06Z on the 16th (down from 40 kt originally) as the cyclone continued farther inland. The cyclone remained over land until early on the 17th before emerging into the Bay of Campeche, and it is analyzed to have weakened to a tropical depression by 18Z on the 16th (HURDAT previously only showed a weakening to a 35 kt tropical storm). After the cyclone emerged into the Bay of Campeche it is analyzed to have strengthened back to a tropical storm by 06Z on the 17th. A 35 kt intensity is analyzed at 06Z (down from 40 kt originally). The highest observed wind at that time was 35 kt at 05Z. The analyzed intensity is 50 kt by 12Z (up from 40 kt originally), as a 45 kt wind was observed later that day. The cyclone made its final Mexican landfall just after 12Z on the 18th. No change was made to the position at 12Z on the 18th, but available observations support holding the 50 kt intensity assigned on the 17th until landfall (up from 35 kt originally at 12Z on the 18th). After landfall, the cyclone is analyzed to have weakened to a tropical depression at 00Z on the 19th and to have dissipated after 00Z (originally, HURDAT dissipated this cyclone after 18Z on the 18th). ******************************************************************************* 1931 Storm 4 – Revised 2012 25380 08/16/1931 M= 6 4 SNBR= 564 NOT NAMED XING=0 SSS=0 25385 08/16* 0 0 0 0*132 580 35 0*137 595 35 0*144 607 35 0 25385 08/16* 0 0 0 0*142 593 25 0*150 605 25 0*159 616 30 0 *** *** ** *** *** ** *** *** ** 25390 08/17*152 620 35 0*162 636 35 0*172 650 35 0*179 659 35 0 25390 08/17*168 627 30 0*177 638 35 0*185 650 35 0*193 662 35 0 *** *** ** *** *** *** *** *** 25395 08/18*186 667 35 0*193 674 35 0*201 681 35 0*212 689 35 0 25395 08/18*201 673 35 0*208 684 30 0*215 695 30 0*221 704 30 0 *** *** *** *** ** *** *** ** *** *** ** 25400 08/19*222 696 35 0*227 700 35 0*232 702 35 0*235 703 35 0 25400 08/19*226 710 30 0*231 714 30 0*235 715 30 0*239 715 30 0 *** *** ** *** *** ** *** *** ** *** *** ** 25405 08/20*240 705 35 0*249 707 35 0*258 708 35 0*266 708 35 0 25405 08/20*243 714 30 0*247 712 30 0*250 708 25 0*255 703 25 0 *** *** ** *** *** ** *** ** *** *** ** 25410 08/21*274 707 35 0*283 701 30 0* 0 0 0 0* 0 0 0 0 25410 08/21*263 698 25 0*273 693 25 0* 0 0 0 0* 0 0 0 0 *** *** ** *** *** ** 25415 TS Minor track changes and minor intensity changes are analyzed for this weak tropical storm. Major changes are made to the timing of when the cyclone attained tropical storm strength and the timing of when the cyclone weakened back to a tropical depression. Evidence for these alterations comes from the Historical Weather Maps Series, the COADS ships database, Monthly Weather Review, Perez (1971), and newspaper reports from The Antigua Magnet provided by Mike Chenoweth. August 16: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 13.7N, 59.5W. Ship/Land highlights: No gales or low pressures. Regarding the intensity: "On Sunday morning (16th) news reached here from Barbados that a hurricane had formed in the vicinity of that island, and that there was a possibility, if not a probability, of Dominica being struck. The news spread fast enough, and although locally there were no signs of any approaching hurricane, anxiety was general enough. At noon, the barometer, which had fallen slightly, appeared to be steady enough, but from three till five o'clock it dropped another tenth. In the meantime, torrential rains began to fall, and many residents considered it advisable to bar up their houses. After five o'clock the glass started to rise and the rains ceased about nine. The night was calm. The following morning 5.40 inches of rainfall were registered at the Botanical Gardens" (The Antigua Magnet, Saturday Aug. 22 1931). "On Sunday afternoon a storm warning was issued. The sky threatened rain and showers actually fell, but around sunset a very peculiar appearance was noticeable in a section of the sky to the east. This lurid appearance emphasized the belief that an atmospheric disturbance of some sort was due and before the sun vanished from the horizon flashes of lightning and peals of thunder were manifest. People began to bolt and bar securely doors and windows and wait for developments. Happily, apart from a continuation of the electrical disturbance and a steady fall of rain nothing serious occurred. The wind never stirred beyond the velocity of a sharp breeze (25 kt) and morning came to give courage to those who might have been maintaining a scared vigil throughout the night watching for the worst in the weather. At time of writing although the sky presented an overcast appearance there was no further indication of unsettled weather" (The Antigua Magnet, Tuesday Aug. 18, 1931). August 17: HWM analyzes a trough near Puerto Rico and the Virgin Islands. HURDAT listed this as a tropical storm at 17.2N, 65.0W. The MWR Tracks for Centers of Cyclones shows a center near 18N, 65.2W. Ship/Land highlights: No gales or low pressures. August 18: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 20.1N, 68.1W. The MWR Tracks for Centers of Cyclones shows a center near 21.4N, 69.5W. Ship/Land highlights: No gales or low pressures. August 19: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 23.2N, 70.2W. The MWR Tracks for Centers of Cyclones shows a center near 23N, 71.6W. Ship/Land highlights: No gales or low pressures. August 20: HWM does not analyze a closed low on this day. HURDAT listed this as a tropical storm at 25.8N, 70.8W. The MWR Tracks for Centers of Cyclones shows a center near 27.2N, 70.2W. Ship highlights: No gales or low pressures. August 21: HURDAT last listed this at 06 UTC as a tropical depression at 28.3N, 70.1W. The MWR Tracks for Centers of Cyclones shows a center near 29N, 69.3W at 00 UTC, and 30.7N, 68.5W at 12 UTC. Ship/Land highlights: No gales or low pressures. HURDAT previously indicated that a tropical cyclone developed on 16 August just east of the Windward Islands. The Atlantic was searched back to 9 August, but no closed circulation was found, so no changes are made to the timing of genesis. HURDAT’s initial intensity was a 35 kt tropical storm, but the cyclone is analyzed to only have contained winds of 25 kt at the time, and thus is begun as a tropical depression. The position on the 16th is adjusted by about 1.5 degrees northwest of the original HURDAT position due to a 5 kt SSW wind near 14.2N, 60.8W along with a few other observations. A 24 kt SW observation on the 17th lays credence to the possibility that the 35 kt intensity in HURDAT may have been correct, and thus there is not enough evidence to decrease or increase the HURDAT intensity on the 17th. The depression is analyzed to have strengthened to a tropical storm at 06Z on the 17th (one day later than originally – a major change). The cyclone is analyzed to have passed through the Virgin Islands as a 35 kt tropical storm on 17 August. Observations showed the closed circulation on the 17th. No gales were observed, but the track on the 17th is adjusted to the right (or north) of the previous HURDAT track by about 1.5 degrees. The weak circulation continued to the west-northwest passing north of Puerto Rico and Hispaniola on the 18th, and it is analyzed that the tropical storm weakened to a 30 kt tropical depression at 06Z on the 18th (three days earlier than originally). The position is adjusted by over a degree on the 18th and 19th in accordance with available observations. The depression turned northward and moved slowly north-northeastward east of the Bahamas for a few more days. While it is possible that the cyclone may have degenerated to an open trough a day earlier than HURDAT shows dissipation, there is not sufficient observational coverage to confirm that so no changes are made to the timing of dissipation in HURDAT, which is listed at 06Z on 21 August. The final position is adjusted to 27.3N, 69.3W (a little over one degree southeast of the previous position) as a 25 kt tropical depression (30 kt originally). Although observations indicate that this system was likely at least a tropical depression, there were no observed winds of tropical storm force or low pressures. This system may not have been a tropical storm since there is no conclusive evidence of tropical storm intensity. However, there is currently not enough evidence to downgrade this system either. It is maintained as a 35 kt tropical storm from 06Z on the 17th through 00Z on the 18th. ******************************************************************************* 1931 Storm 5 (new to HURDAT) – Added in 2012 28416 09/01/1931 M= 4 5 SNBR= NOT NAMED XING=0 SSS=0 28417 09/01*186 609 25 0*187 617 25 0*188 625 25 0*189 632 25 0 28417 09/02*190 639 30 0*191 646 30 0*192 654 30 0*193 664 30 0 28418 09/03*194 676 35 0*195 685 35 0*195 694 40 0*195 708 35 0 28418 09/04*195 723 30 0* 0 0 0 0* 0 0 0 0* 0 0 0 0 28419 TS HWM, COADS, MWR, Perez et al., and Tannehill indicate that a tropical storm, previously undocumented in HURDAT, occurred from 1-4 September and made landfall as a tropical storm in Hispaniola. September 1: HWM does not analyze any features of interest on this day. HURDAT did not previously list this system. The MWR Tracks of Lows shows a 12Z position near 19N, 62W. Ship highlights: 10 kt NW at 12Z at 18.3N, 64.9W (COA). “The first cyclonic development of the month [September] began north of the Virgin Islands on the 1st, and was of minor intensity” (MWR). September 2: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 19N, 66W with a 1010 mb pressure. Ship highlights: 15 kt WNW at 12Z at 18.5N, 66.1W (COA). “Only gales reported during the progress of this relatively mild disturbance were over Mona Passage on the 2d, but flooding rains which caused great damage and some loss of life in Porto Rico may be attributed to conditions attending this cyclone” (MWR 364). September 3: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 19N, 70W with a 1007 mb pressure. Ship highlights: 25 kt SSW with 1008 mb at 00Z at 19.5N, 67.5W (COA); 35 kt SE with 1010 mb at 12Z at 19.7N, 68.1W (HWM); 30 kt E with 1007 mb at 12Z near 20N, 69.5W (Perez). September 4: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 19.5N, 74.5W with a 1011 mb pressure. Ship highlights: 30 kt E with 1013 mb at 00Z at 20.2N, 72.7W (COA). September 5: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 20N, 79W. No gale force winds or low pressures were observed. September 6: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 21.5N, 83.3W with a 1010 mb pressure. No gale force winds or low pressures were observed. September 7: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 25.2N, 82.5W with a 1010 mb pressure. No gale force winds or low pressures were observed. “It moved westward during the next six days reaching the western end of Cuba where it recurved northeastward on the 7th” (MWR). September 8: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 27N, 80W with a 1010 mb pressure. No gale force winds or low pressures were observed. September 9: HWM does not analyze any features of interest on this day. The MWR Tracks of Lows shows a 12Z position near 29N, 77W. No gale force winds or low pressures were observed. This tropical cyclone may have formed from an easterly wave that originated east of the Lesser Antilles. On August 31, a tropical wave appeared near 59W approaching the northern Leeward and Virgin Islands. On the first, observations indicate a closed circulation near 19N, 62.5W at 12Z, but no strong winds or low pressures by that time. A tropical depression is analyzed to have formed at 00Z on 1 September at 18.6N, 60.9W, but it is possible that a cyclone formed before this time since observations were sparse prior to that time farther east over the open tropical Atlantic. On the 2 September HWM map, a ship with 35 kt SSE and 1010 mb is plotted near 19.5N, 68W, but other data indicates that this observation is likely in error. We are guessing that it was plotted on the wrong day, and that this observation occurred at that location at 12Z on the 3rd instead of 12Z on the 2nd. However, backing to the 2nd, other observations continue to indicate a closed circulation centered near 19.2N, 65.4W at 12Z on the 2nd. A 25 kt intensity is analyzed on the 1st, and a 30 kt intensity is analyzed on the 2nd. On the 3rd, the cyclone continued to move due west and approached Hispaniola. On this day, in addition to the aforementioned 35 kt ship observation, there was a separate observation of 1007 mb with 30 kt E north of the center. West winds south of the center on the 3rd continue to indicate a closed circulation. Another important factor is that there was a high environmental pressure to the north. The pressure at Turks Island was 1015 mb at 12Z on the 3rd while the 1007 mb was measured 100 nmi to the SSE of that. These factors are enough evidence that this system was a tropical storm on 3 September. The depression is analyzed to have strengthened to a tropical storm at 00Z on 3 September, intensifying to a 40 kt tropical storm at 12Z on the 3rd at 19.5N, 69.4W. The cyclone is analyzed to have made landfall in Hispaniola on the 3rd at 14Z at 19.5N, 69.9W as a 40 kt tropical storm. Moving due westward over Hispaniola, the cyclone is analyzed to have weakened to a 30 kt tropical depression at 00Z on 4 September at 19.5N, 72.3W (still over Hispaniola). The cyclone is analyzed to have degenerated into an open wave or trough after that time. The remnants of the tropical storm can be tracked to the area south of Cuba on the 5th and 6th, over Florida on the 7th and 8th, and into the western Atlantic off the southeast coast of the US on the 9th. After that, it was absorbed by a frontal system. Observations from the 4th – 10th indicate the cyclone was an open trough during that time - not a closed low. Also of note, please see the suggested track by Monthly Weather Review on p.348, indicated as III. Tannehill and Perez et al. also describe this system as a tropical storm. ******************************************************************************* 1931 Storm 6 (originally Storm 5) – Revised 2012 25420 09/05/1931 M= 8 5 SNBR= 565 NOT NAMED XING=0 SSS=0 25420 09/06/1931 M= 8 6 SNBR= 565 NOT NAMED XING=0 SSS=0 * * The 5th has been removed from HURDAT. 25425 09/05* 0 0 0 0* 0 0 0 0* 0 0 0 0*125 555 35 0 25430 09/06*126 593 35 0*127 610 35 0*128 628 35 0*130 641 35 0 25430 09/06* 0 0 0 0* 0 0 0 0* 0 0 0 0*124 627 30 0 *** *** ** *** *** ** *** *** ** *** *** ** 25435 09/07*133 652 35 0*137 665 40 0*142 679 40 0*148 693 40 0 25435 09/07*128 645 35 0*132 662 40 0*135 679 40 0*138 697 45 0 *** *** *** *** *** *** *** ** 25440 09/08*153 706 40 0*157 715 45 0*160 724 45 0*164 740 50 0 25440 09/08*140 715 50 0*142 732 55 0*145 748 60 0*148 764 65 0 *** *** ** *** *** ** *** *** ** *** *** ** 25445 09/09*167 758 50 0*168 777 55 0*168 795 55 0*169 812 60 0 25445 09/09*150 779 65 0*152 793 70 0*155 807 70 0*158 822 75 0 *** *** ** *** *** ** *** *** ** *** *** ** 25450 09/10*170 829 60 0*171 845 65 0*173 861 85 0*176 879 110 0 25450 09/10*162 837 85 0*166 851 95 0*170 865 105 0*174 878 115 0 *** *** ** *** *** ** *** *** *** *** *** *** 25455 09/11*180 895 60 0*185 908 55 0*191 921 50 0*197 934 50 0 25455 09/11*179 891 80 0*185 904 55 0*191 916 50 0*198 927 50 0 *** *** ** *** *** *** *** 25460 09/12*203 947 50 0*209 962 55 0*215 979 55 0*221 995 35 0 25460 09/12*206 938 50 0*214 949 50 0*222 960 45 0*227 969 40 0 *** *** *** *** ** *** *** ** *** *** ** The 13th is new to HURDAT. 25462 09/13*231 977 35 0*234 985 30 0*237 993 25 0* 0 0 0 0 25465 HR Major track changes and major intensity alterations are analyzed for this hurricane, originally storm #5. Major changes are made to the timing of genesis as well as the timing of when both the tropical storm and hurricane intensities were first attained. Evidence for these alterations comes from the Historical Weather Map Series, Monthly Weather Review, and the COADS ship database. Aug 29: HWM indicates a closed low at about 9N and 20W of at most 1010mb at 12UTC. HURDAT does not start the storm yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Aug 30: HWM indicates a stronger system at 4N and 31.5W of at most 1005mb at 12UTC. HURDAT does not start the storm yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Aug 31: HWM indicates a closed low at 10N and 28W of at most 1005mb at 12UTC. HURDAT does not start the storm yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 1: HWM loses the system for the next several days. HURDAT does not list a storm yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 2: Neither HWM nor HURDAT show a system. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 3: Neither HWM nor HURDAT show a system. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 4: Neither HWM nor HURDAT show a system. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 5: HWM does not show a system. HURDAT begins this system as a tropical storm at 12.5N, 55.5W at 18UTC. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 6: HWM does not show a system. HURDAT lists this system as a tropical storm at 12.8N, 62.8W at 12UTC. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. "It was first suspected not far from Barbados on the 6th... developed into storms of relatively small diameter but of full hurricane intensity as the progressed during the succeeding week "(MWR). Sept 7: HWM indicates a small closed low of 1010mb near 16N, 68W at 12 UTC. HURDAT lists this system as a tropical storm at 14.2N, 67.9W at 12UTC. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 8: HWM indicates a closed low of 1005mb near 14.5N, 74.8W at 12UTC. HURDAT lists this system as a tropical storm at 16.0N, 72.4W at 12UTC. Ship highlights: 35kt S with 1002mb at 14.8N, 71.8W at 4UTC (MWR); 60kt NE with 1000mb at 15.3N, 76.5W at 14Z (MWR). Station highlights: no gales or low pressures. “The progress of this disturbance continued steadily west-northwestward during the next two [8th and 9th] days” (MWR). Sept 9: HWM indicates a closed low of at most 1000mb near 15.5N, 82W at 12UTC. HURDAT lists this system as a tropical storm at 16.8N, 79.5W at 12UTC. Ship highlights: 50kt SSE with 995mb at 16.1N, 81.8W at 1830UTC (MWR); 60kt E later than 1830UTC at 16.1N, 81.8W (MWR). Sept 10: HWM indicates a tiny closed low of at most 1000mb near 16N, 86W at 12UTC. HURDAT lists this system as a Category 2 hurricane 17.3N 86.1W at 12UTC. Ship highlights: 50kt S with 1002mb at 16.8N, 87.0W at 17UTC (COA). Station highlights: 52 kt NE and 952 mb at 1815Z and 115kt N between 1950-2000 UTC at Belize (MWR). "[This] storm ravaged Belize, British Honduras, on the afternoon of September 10, but ships encountering it earlier did not find winds of hurricane force ... The hurricane, still of small extent but of ferocious intensity, moved in upon the town. It raged throughout much of the afternoon, reaching hurricane velocity about 1 p. m., and the center of the storm appears to have passed Belize about 3:30 p. m... The winds swept the sea forward over the environs of the port, which is built on exceedingly low ground, choked the moth of the Belize River with the wreckage of small boats, including six Honduran schooners, piled a 200-ton dredge upon the wharf, and with wreckage as battering rams, smashed into the structures of the town itself. It was a disaster of major proportions, entailed a loss of life that is not definitely known, but probably exceeding 1,500 souls, and a property loss that was estimated in later dispatches at $7,500,000” (MWR). Sept 11: HWM indicates a closed low of at most 1010mb near 20N, 93W at 12UTC. HURDAT lists this system as a tropical storm at 19.1N, 92.1W at 12UTC. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 12: HWM loses the system today. HURDAT lists this system as a tropical storm at 21.5N, 97.9W at 12UTC. Ship highlights: 985mb at 29.3N, 93.3W at 12UTC (COA). Station highlights: 17 kt W with 1010 mb at 9/12 20Z at Tampico (22.2N, 97.9W). Sept 13: HWM does not show a system. HURDAT does not list this system anymore. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. This hurricane may have originated from an easterly wave that emerged off the African coast around 28 August. There were some observations in the general vicinity of a disturbance or possible tropical cyclone in the tropical eastern Atlantic from 29-31 August, but there are no observations over the central tropical Atlantic from 1-5 September as the disturbance may have continued westward. The observations in the eastern Atlantic do not provide enough evidence of a closed circulation to begin this cyclone early. In fact, observations indicate that genesis occurred 24 hours earlier than shown in HURDAT. The system is begun at 18Z on the 6th as a 30 kt tropical depression about a degree and a half east-southeast of the original HURDAT with development into a tropical storm six hours later. The cyclone moved west-northwestward through the Caribbean Sea and slowly intensified from 7 to 9 September. Track changes on the 7th were minor, but on the 8th, ship observations near 15.3N, 76.5W indicate a position about two and a half degrees WSW of the previous HURDAT position at 12Z. The first observed gale associated with this cyclone occurred at 12Z on the 7th – 35 kt from a ship. The 40 kt intensity shown in HURDAT at 12Z on the 7th is not changed. It is analyzed that tropical storm intensity was first attained at 18Z on the 6th (24 hours later than originally – a major change). On the 8th at 04Z, a peripheral pressure of 1002 mb suggests winds of greater than 43 kt according to the Brown et al. southern pressure-wind relationship, and at 14Z, a peripheral pressure of 1000 mb (with 60 kt winds) suggests winds of greater than 47 kt using the same relationship. Intensities of 60 and 65 kt are chosen for 12 and 18Z on the 8th (up from 45 and 50 kt originally) due to the 60 kt wind observation at 14Z. The cyclone is analyzed to have reached hurricane strength by 18Z on the 8th (30 hours earlier than originally – a major change). On the 9th at 1830Z, as the cyclone was passing northeast of the coast of Central America near the border of Nicaragua and Honduras, a ship measured a peripheral pressure of 995 mb (observed with 50 kt winds) indicating a wind speed of greater than 56 kt according to the southern pressure-wind relationship. The hurricane continued west-northwestward and is analyzed to have rapidly intensified on the 10th before it made landfall at Belize City, Belize around 20Z on the 10th at 17.5N, 88.2W. A peripheral pressure of 952 mb was observed simultaneously with 52 kt NE wind at Belize City at 1815Z. This was followed by the highest wind recorded at Belize City of 115 kt N between 1950-2000Z. The eye passed over Belize City between 2005-2044Z, but no central pressure was recorded. The 952 mb pressure suggests winds of at least 109 kt from the Brown et al. south of 25N pressure-wind relationship and 111 kt from the intensifying subset. A 115 kt intensity is chosen for 18Z on the 10th and landfall (up from 110 kt originally – which makes this a Category 4 hurricane for Belize). The cyclone weakened substantially as it moved west-northwestward over the Yucatan Peninsula and it emerged into the Bay of Campeche as a tropical storm on 11 September between 06-12Z. Runs of the Kaplan and DeMaria inland decay model yield 79 and 57 kt for 00 and 06Z on the 11th. Available observations over land near the cyclone were very sparse at 00 and 06Z and thus no gales were found at those times. Analyzed (original HURDAT) intensities at 00 and 06Z on the 11th are 80 kt (60 kt) and 55 kt (55 kt). Very little ship data is available over the Bay of Campeche on the 11th and 12th, but available observations indicate that the cyclone maintained a closed circulation and moved inland about 50 or 60 nmi north of Tampico around 00Z on the 13th. The intensity of the cyclone during the time in the Bay of Campeche is highly uncertain due to very little data. The analyzed intensity for this landfall is 35 kt. HURDAT previously showed a final position at 18Z on the 12th well inland at 22.1N, 99.5W as a 35 kt tropical storm. The revised HURDAT shows a position at 18Z on the 12th at 22.7N, 96.9W (a major eastward track adjustment) with a 40 kt intensity. Soon after landfall, the cyclone weakened to a tropical depression and then dissipated, but 18 hours are added to HURDAT before dissipation is analyzed. The revised final position at 12Z on 13 September is 23.7N, 99.3W as a 25 kt tropical depression. ******************************************************************************* 1931 Storm 7 (originally Storm 6) – Revised 2012 25470 09/08/1931 M= 9 6 SNBR= 566 NOT NAMED XING=0 SSS=0 25470 09/08/1931 M= 9 7 SNBR= 566 NOT NAMED XING=0 SSS=0 * 25475 09/08* 0 0 0 0* 0 0 0 0* 0 0 0 0*172 528 40 0 25475 09/08* 0 0 0 0* 0 0 0 0* 0 0 0 0*152 530 40 0 *** *** 25480 09/09*173 538 45 0*174 554 45 0*175 570 50 0*176 586 55 0 25480 09/09*154 546 45 0*157 563 45 0*161 580 50 0*167 595 55 0 *** *** *** *** *** *** *** *** 25485 09/10*177 602 55 0*179 616 60 0*181 628 65 0*182 639 85 988 25485 09/10*173 609 55 0*179 622 60 0*183 634 65 0*184 644 70 0 *** *** *** *** *** *** *** ** *** 25490 09/11*183 651 80 0*184 664 70 0*185 679 60 0*184 696 60 0 25490 09/11*185 654 75 987*185 666 70 0*185 679 65 0*184 694 55 0 *** *** ** *** *** *** ** *** ** 25495 09/12*183 713 55 0*182 728 55 0*181 743 55 0*181 761 55 0 25495 09/12*183 709 45 0*182 725 40 0*181 741 45 0*181 757 60 0 *** ** *** ** *** ** *** ** 25500 09/13*181 780 55 0*182 798 60 0*183 813 60 0*183 826 60 0 25500 09/13*181 773 55 0*181 787 60 0*182 801 60 0*182 816 60 0 *** *** *** *** *** *** *** 25505 09/14*183 838 60 0*183 851 60 0*184 863 60 0*185 875 60 0 25505 09/14*183 832 60 0*183 847 60 0*184 862 60 0*185 875 60 0 *** *** *** 25510 09/15*187 886 50 0*190 904 55 0*193 914 65 0*194 928 75 0 25510 09/15*187 888 50 0*190 901 45 0*193 914 55 0*194 927 65 0 *** *** ** ** *** ** 25515 09/16*193 937 75 0*191 949 75 0*188 962 70 997*185 974 35 0 25515 09/16*193 940 75 0*191 953 85 0*188 966 70 0*185 978 35 0 *** *** ** *** *** *** 25520 HR Major track changes and major intensity changes are analyzed for this hurricane, originally storm #6. Evidence for these alterations comes from the Historical Weather Map Series, Monthly Weather Review, the COADS ship database, Perez (1971), Boose et al. (2004), personal communication from Jose Colon (2010), and Mexican station observations provided by Ricardo Prieto and Jorge Sanchez-Sesma. Sept 8: HWM does not show a system. HURDAT begins this system as a tropical storm at 17.2N, 52.8W at 18UTC. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 9: HWM does not show a system. HURDAT lists this system as a tropical storm at 17.5N, 57.0W at 12UTC. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. “The first intimation of abnormal weather previous to this storm was an almost perfect wide quadrant of wind directions extending from the Virgin Islands to Barbados on the morning of the 9th. The appearance at that time was that the area named was in the southwest periphery of a very wide cyclone area” (MWR). Sept 10: HWM indicates a low near 15.5N, 65.5W at 12UTC. HURDAT lists this system as a Category 1 hurricane at 18.1N, 62.8W at 12UTC. MWR's Tracks of Lows indicates a center at 18N, 64W (am) and at 18N, 66W (pm). Ship highlights: no gales or low pressures. Station highlights: 52kt at St. Thomas (MWR); 1001 mb at St. Thomas (MWR). “According to the accustomed nomenclature of West Indian storms the one which raked the north coast of Porto Rico on the night of September 10 has been named ‘San Nicolas’ from the saint’s day of that date... By the morning of the 10th the center had passed through the Leewards somewhere near St. Martin and was approaching the U.S. Virgin Islands of St. Thomas and St. Croix ... By the time it had reached San Juan the intensity had increased to a low pressure of 29.17 inches [988 mb] and an estimated wind velocity of 90 miles per hour. This estimate is based partially upon a stop watch record made by Pan-American Airways (Inc.) officials with their 4-cup Robinson anemometer at the air field and, of course, the total mileage and the dial readings of our own [San Juan Weather Bureau Office] anemometer” (MWR). Sept 11: HWM does not show a system. HURDAT lists this system as a tropical storm with 60kt winds at 18.5N, 67.9W at 12UTC. MWR's Tracks of Lows indicates the center at 18N, 68W (am) and at 17.5N, 72W (pm). Ship highlights: no gales or low pressures. Station highlights: 78kt (estimated) at San Juan (MWR); 10 kt with 988 mb at San Juan at 3UTC (MWR). “1931 Sept. 10-11, San Nicolas, Hurricane of small diameter... The hurricane entered north of Fajardo at 8:00 p.m., San Juan at 10:00 p.m., remained over the island that night for 6 hours, moved west at 17 mph, and left Aguadilla at 2:00 a.m. of Sept. 11th. Destruction extended over an area 10 to 12 miles wide, and damages were mostly to crops, estimated at $200,000. 2 deaths” (Perez). “Two lives were lost and several minor injuries reported in San Juan. Much plate glass and light construction were destroyed, and some 50,000 boxes of fruit blown from the trees. The damage was confined to a strip of 5 or 6 miles in width extending from San Juan to Aguadilla, the damage varying considerably in this area with the character of the crops. The destructive portion of the storm was hardly more than 10 or 12 miles in diameter and the northern half of this was off shore. There was an interval of 15 minutes at San Juan which represented the center of the storm, but it is the opinion of the writer that the actual center passed a short distance north of San Juan as the first renewal of the wind was from the southwest, then after several minutes it became southeasterly. The wind during the first portion of the storm held northwest with practically no variation until the lull ... the center passing ... with decreased intensity over Santo Domingo City, then again increasing throughout the remaining length of the Caribbean Sea” (MWR). “Sep 10-11. “San. Nicolas, several F2 impacts – recommends 80 kt at landfall in Puerto Rico” (Boose et al.). Sept 12: HWM now shows a closed low of at most 1010mb near 17.5N, 76.5W at 12UTC. HURDAT lists this system as a tropical storm at 18.1N, 74.3W at 12UTC. MWR's Tracks of Lows indicate the center at 17.5N, 76W (am) and at 18N, 78W (pm). Ship highlights: 60kt SSE with 1006mb at 18.2N, 77.0W at 19UTC (MWR). Station highlights: no gales or low pressures. Sept 13: HWM indicates a closed low of at most 1010mb near 16N, 83.5W at 12UTC. HURDAT lists this system as a tropical storm at 18.3N, 81.3W at 12UTC. MWR's Tracks of Lows indicate the center at 18N, 82W (am) and at 18.5N, 84W (pm). Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 14: HWM does not show a system. HURDAT lists this system as a tropical storm at 18.4N, 86.3W at 12UTC. MWR's Tracks of Lows indicates the center with 1005mb at 19N, 87W (am) and at 19N, 89.5W (pm). Ship highlights: 35kt ENE at 19.4N, 85.2W at 12UTC (HWM). Station highlights: 30kt E with 1010mb at Cozumel at 12UTC (HWM). Sept 15: HWM does not show a system anymore. HURDAT lists this system as a Category 1 hurricane at 19.3N, 91.4W, at 12UTC. MWR's Tracks of Lows indicate the center at 19N, 92.5W (am) and at 19N, 95W (pm). Ship highlights: no gales or low pressures. Station highlights: 44 kt S and 1012 mb at ~02 UTC at Chetumal, Mexico (MX). Sept 16: HURDAT lists this system as a Category 1 hurricane at 18.8N, 96.2W at 12UTC. MWR's Tracks of Lows indicates the center with 997mb at 19.5N, 97.5W only in the morning. Ship highlights: no gales or low pressures. Station highlights: 997mb at Veracruz at 9UTC and 12UTC (MWR); 83kt E at Veracruz at ~1015UTC (MWR, MX). HURDAT starts this system on 8 September at 18Z as a 40 kt tropical storm at 17.2N, 52.8W. The timing of genesis and the 40 kt intensity at 18Z on the 8th are both not changed, but the position is moved two degrees south of the original HURDAT position. Major south-southwestward track adjustments are implemented from 18Z on the 8th through 00Z on the 9th. From 06Z-18Z on the 9th, southwestward track adjustments of between 1 and 2 degrees are implemented. These adjustments were based on observations on the 9th. From 00Z on the 10th through 00Z on the 13th, all track changes are less than one degree changes. Observations are sparse on the 8th through the 10th, but Colon (2002) edited by Perez indicates that the cyclone passed north of St. Martin during the afternoon of the 10th and closer and to the north of St. Thomas on the 10th around sunset. This indicates that the cyclone moved west-northwestward from the 8th to the 10th. At St. Thomas, a pressure of 1001 mb and winds of around 52 kt were reported. The revised track has the center of the cyclone passing just a very short distance north of both St. Martin and St. Thomas on the 10th, placing these islands on the typically weaker, left side of the storm. No changes to the intensity are analyzed from the 8th through 12Z on the 10th, at which time hurricane intensity is shown to have been attained. The cyclone turned westward and moved due west along the north coast of Puerto Rico early on the 11th. The center of the cyclone made landfall at some points on the Puerto Rican coastline and remained just offshore at other points. A maximum wind of 78 kt was estimated at San Juan before the lull associated with the center was experienced there. A 988 mb minimum pressure (simultaneous with 10 kt winds) was recorded at San Juan inside the RMW. This suggests a central pressure of about 987 mb, and this value is added to HURDAT at 00Z on the 11th. The 988 mb central pressure listed in HURDAT originally at 18Z on the 10th is removed. A central pressure of 987 mb equals 68 kt according to the Brown et al. southern pressure wind relationship and for its intensifying subset. A 75 kt intensity is chosen at 00Z on the 11th (down from 80 kt originally). The assessment of Boose has 80 kt for the Puerto Rican landfall. HURDAT previously listed an intensity of 85 kt at 18Z on the 10th, and the intensity at that time is lowered to 70 kt. After 03Z on the 11th, when the hurricane made its closest approach to San Juan, the center continued moving due west along the north coast of Puerto Rico. By about 09Z on the 11th, the cyclone had finished interacting with the island of Puerto Rico and it moved over water before making landfall in the Dominican Republic around 14Z on the 11th. At this point, the center is analyzed to have moved slightly south of due west, or about 265 degrees for the next 24 hours or so. The cyclone was over or interacting with the island of Hispaniola from 14Z on the 11th to 12Z on the 12th. Since there are no more observations of the peak intensity on the 11th, and since the cyclone was interacting with land, the analyzed intensity is decreased by 10 kt every 6 hr from 18Z on the 11th to 00Z on the 12th and then bottoming out at 40 kt at 06Z on the 12th (originally 55 kt). At 12Z on the 12th, the cyclone emerged over water between Haiti and Jamaica. A 60 kt ship at 19Z indicates that the system quickly rebounded once it left the coast of Hispaniola, so the intensity is bumped up to 45 kt at 12Z and 60 kt at 18Z over the Caribbean. 60 kt is also the landfall intensity for Jamaica, though it is possible that this system reached minimal hurricane intensity briefly before reaching the coast. The cyclone was over Jamaica from 20Z on the 12th to 03Z on the 13th. It continued westward and made landfall slightly north of Belize’s border with the Yucatan Peninsula of Mexico around 19Z on the 14th. The positions on the 13th are shifted about 1 degree to the east of the previous HURDAT positions, but very minor track changes of less than half a degree are analyzed for the remainder of the cyclone’s lifetime. The HURDAT intensity of 60 kt from 12Z on the 13th through 18Z on the 14th is not changed due to a lack of observations. However, one important observation – a max wind of 44 kt (1-minute) at Chetumal, is good evidence that the tropical storm was maintaining its intensity. The cyclone is analyzed to have passed very slightly to the north of that station around 22Z on the 14th. The cyclone is analyzed to have weakened to 50 kt by 00Z on the 15th, and a 45 kt intensity is analyzed at 06Z on the 15th (down from 55 kt originally) as the cyclone moved further inland. It emerged over the Bay of Campeche around 10Z on the 15th, and then made its final landfall just east of Veracruz on the 16th at 09Z at 18.9N, 95.9W. Veracruz reported a maximum wind of 83 kt from the east at 1015Z (pressure missing). The lowest available pressure from Veracruz is 997 mb recorded at 09Z (wind missing), but the pressure at the time of the maximum wind was likely much lower. 85 kt is chosen for the intensity at 06Z on the 16th (up from 75 kt originally) and landfall. A 40 kt intensity increase in 24 hours is analyzed from 06Z on the 15th to 06Z on the 16th. Runs of the Kaplan and DeMaria inland decay model yield 65 kt for 12Z on the 16th and 46 kt for 18Z. Highest observed winds within 2 hr of synoptic times are 83 kt at 12Z and there are no available observations from 18Z. No changes are made to the original intensities listed in HURDAT at 12 and 18Z of 70 and 35 kt respectively. The cyclone moved over the high terrain of Mexico between 12-18Z, and a more rapid dissipation occurred after that time compared with what Kaplan and DeMaria would suggest. No change is made to the timing of dissipation. ******************************************************************************* 1931 Storm 8 (originally Storm 7) – Revised 2012 25525 09/25/1931 M= 3 7 SNBR= 567 NOT NAMED XING=0 SSS=0 25525 09/23/1931 M= 7 8 SNBR= 567 NOT NAMED XING=0 SSS=0 ** * * The 23rd and 24th are new to HURDAT. 25527 09/23* 0 0 0 0*185 517 25 0*190 520 30 0*196 523 30 0 25528 09/24*202 526 35 0*208 528 35 0*215 530 40 0*223 532 40 0 25530 09/25* 0 0 0 0*223 530 35 0*250 545 35 0*263 548 35 0 25530 09/25*232 533 45 0*241 534 45 0*250 535 50 0*261 535 50 0 *** *** ** *** *** ** *** ** *** *** ** 25535 09/26*274 547 35 0*284 543 35 0*293 539 35 0*301 535 35 0 25535 09/26*273 531 50 0*285 527 50 0*297 523 50 0*306 522 50 0 *** *** ** *** *** ** *** *** ** *** *** ** 25540 09/27*309 530 35 0*316 525 35 0*324 520 35 0*335 510 30 0 25540 09/27*313 522 55 0*320 522 55 0*328 522 60 0*339 522 60 0 *** *** ** *** *** ** *** *** ** *** *** ** The 28th and 29th are new to HURDAT 25542 09/28*353 522 65 0*370 520 65 0*390 512 60 0E410 501 55 0 25543 09/29E428 487 55 0E448 463 50 0* 0 0 0 0* 0 0 0 0 25545 TS 25545 HR ** Minor track changes and major intensity changes are analyzed for this cyclone, originally storm #7. Major changes are analyzed to the genesis and dissipation (the cyclone is begun two days earlier and ended a day later), and the peak intensity is now shown to have been a hurricane (previously only a tropical storm). Evidence for these alterations comes from the Historical Weather Map Series and the COADS ship database. Sept 22: HWM does not show a system. HURDAT does not list the system yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 23: HWM does not show a system. HURDAT does not list the system yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept 24: HWM indicates a low pressure near 21N, 57W at 12UTC. HURDAT does not list the system yet. Ship highlights: 35kt SSE with 1006mb at 21.5N, 51.5W at 12UTC (COA). Station highlights: no gales or low pressures. Sept 25: HWM shows a closed low of at most 1015mb near 25N, 55W at 12UTC. HURDAT begins this system as a tropical storm at 22.3N, 53.0W at 6UTC. Ship highlights: 45kt S at 24.7N, 52.1W at 12UTC (COA). Station highlights: no gales or low pressures. Sept 26: HWM shows a closed low of at most 1015mb near 31N, 51.5W at 12UTC. HURDAT lists this system as a tropical storm at 29.3N, 53.9W at 12UTC. Ship highlights: 35kt S with 1011mb at 29.5N, 49.5W at 0UTC (COA). Station highlights: no gales or low pressures. Sept 27: HWM shows a closed low of at most 1015mb at 32.5N, 53W at 12UTC. HURDAT lists this system as a tropical storm at 32.4N, 52.0W at 12UTC. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Sept. 28: HWM does not show a system. HURDAT does not list the system anymore. Ship highlights: 60kt SE with 1001mb at 36.5N, 52.5W at 3UTC (COA); 45kt W with 991mb at 36.5N, 52.5W at 6UTC (COA). Originally, HURDAT indicated that a tropical storm formed on 25 September at 06Z at 22.3N, 53.0W with a 35 kt intensity. Available observations from HWM and COADS indicate that a closed circulation formed on 23 September and the first gale associated with the system occurred on the 24th. This cyclone is begun as a tropical depression on 23 September and the intensity is increased to tropical storm strength on the 24th. On the 23rd and 24th, the cyclone moved slowly north-northwestward from 18.5N, 51.7W to 23.2N, 53.3W by 00Z on the 25th. Track changes on the 25th and 26th range from one to two degrees. The revised intensities on the 24th and 25th were determined by choosing a wind speed 5 kt above the highest available ship observation. A 40 kt intensity is chosen on the 24th at 12 and 18Z due to two 35 kt ship observations on the 24th. The intensity is bumped up to 50 kt by 12Z on the 25th (up from 35 kt originally) due to a 45 kt ship observation at that time. Since the highest observed wind on the 26th is 35 kt, the 50 kt intensity is held through the 26th. On the 26th and 27th, the cyclone was moving slowly northward, crossing 30N in the central Atlantic, but no gales were observed on the 27th. Although there were ships in the outer circulation on the 27th, there were none in the high wind area that day. Although HURDAT lists a final position at 18Z on the 27th as a 30 kt tropical depression, ships in the area early on the 28th indicate that the tropical cyclone had strengthened from a few days prior. A time series from what appears to be either a single ship or two ships in a similar location on the 28th from 00-12Z revealed a highest reported wind of 60 kt (with 1001 mb) and three hours later a lowest reported pressure of 991 mb (with 45 kt- possibly inside the RMW). The data shows isothermal air temperatures on all sides of the low around 73 to 75 degrees. The highest winds are found close to the center and the cyclone’s structure appears still tropical on the 28th. A peripheral pressure of 991 mb suggests winds of greater than 61 kt according to the Landsea et al. (2004) north of 35N pressure-wind relationship. However, using the 10-kt per mb rule (assuming the 991 mb with 45 kt observation is inside the RMW), the central pressure was likely near 987 mb. A central pressure of 987 mb yields a wind speed of 66 kt according to the north of 35N pressure-wind relationship. This observation, combined with the 60 kt wind observed three hours earlier, provides good evidence that this system was a 65 kt hurricane. A 65 kt intensity is chosen for 00 and 06Z on the 28th, making the cyclone a hurricane. The 50 kt intensity, which is analyzed from 12Z on the 25th through 18Z on the 26th, is slowly ramped up to 65 kt by 00Z on the 28th, so that by the final point in the original HURDAT at 18Z on the 27th, a 60 kt intensity is analyzed (up from 30 kt originally). Major upward intensity revisions of 20-30 kt are implemented at all times on the 27th. The hurricane is analyzed to have weakened to a tropical storm at 12Z on the 28th. Observations indicate that the cyclone became extratropical by 18Z on the 28th as it continued moving northeastward. The cyclone is analyzed to have weakened to 50 kt by 06Z on the 29th, because after a 45 kt gale was observed at 07Z on the 29th, no more gales were observed in the vicinity of this system. The revised final position, at 06Z on the 29th is 44.8N, 46.3W as a 50 kt extratropical cyclone. Thereafter, the cyclone dissipated or may have been absorbed by a front ahead of another approaching extratropical low. ******************************************************************************* 1931 Storm 9 (new to HURDAT) – Added in 2012 25546 10/13/1931 M= 4 9 SNBR= NOT NAMED XING=0 SSS=0 25547 10/13* 0 0 0 0* 0 0 0 0*248 756 30 0*251 762 30 0 25548 10/14*254 769 30 0*258 776 30 0*262 781 30 0*267 781 30 0 25549 10/15*273 780 30 0*279 778 35 0*285 774 35 0*291 761 40 0 25549 10/16*300 740 40 0*311 718 40 0E325 692 35 0* 0 0 0 0 HWM, MWR, and COADS indicate that a tropical storm, previously undocumented in HURDAT, occurred from 13-16 October in the western Atlantic. October 12: HWM does not analyze a closed low. HURDAT did not previously list this system. No gales or low pressures. October 13: HWM analyzes a closed low of at most 1010 mb near 24N, 75W. The MWR tracks of centers of cyclones shows a 12Z position near 25N, 77W. No gales or low pressures. October 14: HWM analyzes a closed low of at most 1010 mb near 26N, 78W. The MWR tracks of centers of cyclones shows a 12Z position near 27N, 78W with a 1010 mb pressure. No gales or low pressures. October 15: HWM analyzes a closed low of at most 1010 mb centered near 28N, 77W. The MWR tracks of centers of cyclones shows a 12Z position near 29N, 75W. Ship highlights: 35 kt S before 22Z slightly north of NNE of 28.9N, 73.3W (MWR); 30 kt SW with 1003 mb at 22Z at 28.9N, 73.3W (MWR). October 16: HWM analyzes a spot low near 35N, 70W in an elongated trough with an occluded front extending from 45N, 75W to 41N, 73W, becoming a cold front at 38N, 74W extending to 35N, 79W to 33N, 84W to 32N, 91W. The MWR tracks of centers of cyclones shows a 12Z position near 36N, 69W with a 1001 mb pressure. Ship highlights: 20 kt WNW with 1001 mb at 12Z at 31.0N, 69.2W (COA). A low pressure system formed over the Bahamas on 12-13 October. The low may have formed from a decayed frontal boundary, but temperatures were warm and the structure was tropical. On the 12th, there were not any west winds and it was still a trough. On the 13th, there was a SSW wind, and based on this, the system is begun as a 30 kt tropical depression at 12Z on 13 October at 24.8N, 75.6W. The cyclone moved slowly west-northwestward and at 12Z on the 14th was located over the northwestern Bahamas. On the 15th, the cyclone began a turn to the northeast. The only gale directly associated with the cyclone was measured on the afternoon of the 15th – a 35 kt wind from a ship. The cyclone is analyzed to have strengthened to a tropical storm at 06Z on the 15th. The same ship recorded a 1003 mb pressure with 30 kt winds at 22Z on the 15th at 28.9N, 73.3W. The analyzed position at 00Z on the 16th is 30.0N, 74.0W. Assuming a central pressure in the ballpark of 1000 mb, that equals 44 kt according to the Brown et al. north of 25N pressure-wind relationship and 45 kt for its intensifying subset. The cyclone appears to have had a somewhat broader inner-core or circulation than a normal tropical cyclone, so 40 kt is chosen for the peak intensity from 18Z on the 15th through 06Z on the 16th. By that time, the cyclone began accelerating northeastward ahead of an approaching frontal system emerging off the east coast of the United States. Ship observations at 12Z on the 16th indicate pressures below 1005 mb over a very large area between 30-42N, 64-74W. The analysis indicates that there were likely two sources that combined to produce this broad area of low pressure – the tropical cyclone to the south and the system to the north emerging off the east coast of the United States. Since observations in between the two lows are sparse at 12Z on the 16th, it is possible that they were still two separate entities at 12Z. The tropical cyclone is analyzed to have become extratropical at 12Z on the 16th with a position of 32.5N, 69.2W and a 35 kt intensity. The other low to the north was located near 36N, 70W at that time. The position of the former tropical cyclone at 12Z on the 16th is analyzed to be the final position before the cyclone combined with the other area of low pressure to its north. ******************************************************************************* 1931 Storm 10 (originally Storm 8) – Revised 2012 25550 10/18/1931 M= 5 8 SNBR= 568 NOT NAMED XING=0 SSS=0 25550 10/18/1931 M= 5 10 SNBR= 568 NOT NAMED XING=0 SSS=0 ** 25555 10/18* 0 0 0 0* 0 0 0 0* 0 0 0 0*170 860 35 0 25555 10/18* 0 0 0 0* 0 0 0 0*172 855 30 0*180 847 35 0 *** *** ** *** *** 25560 10/19*193 831 40 0*202 817 40 0*210 804 40 0*219 790 35 0 25560 10/19*188 838 40 0*197 828 40 0*206 816 40 0*217 802 40 0 *** *** *** *** *** *** *** *** ** 25565 10/20*228 775 35 0*234 763 35 0*240 749 35 0*252 724 35 0 25565 10/20*230 781 35 0*244 756 40 0*258 731 40 0*267 706 40 0 *** *** *** *** ** *** *** ** *** *** ** 25570 10/21*265 697 40 0*276 673 40 0*287 648 40 0*297 623 40 0 25570 10/21E272 685 45 0E276 668 45 0E280 648 50 0E285 623 55 0 **** *** ** * *** ** **** ** **** ** 25575 10/22*304 594 40 0*308 563 35 0*312 531 30 0*316 509 25 0 25575 10/22E293 594 55 0E303 563 55 0E312 534 55 0E316 509 55 0 **** ** **** ** * *** ** * ** 25580 TS Major track changes and major intensity changes are analyzed for this tropical storm, originally storm #8. A major alteration also is to indicate an extratropical cyclone stage for the last two days of its existence. Evidence for these alterations comes from the Historical Weather Map Series, Monthly Weather Review, COADS ship database, and Perez et al. (2000). October 16: HWM indicates there is a broad low near 10N, 82.5W at 12UTC. HURDAT does not list this system yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. Perez et al. – after Ortiz – suggest starting the system as a tropical depression on the 16th and 17th in the western Caribbean. October 17: HWM indicates a broad low of at most 1010mb centered roughly near 14N, 87W at 12UTC. HURDAT does not list this system yet. Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. October 18: HWM suggests the presence of a N-S trough in the western Caribbean Sea and analyzes a spot low near 13.5N, 82W at 12 UTC. HURDAT begins this system as a tropical storm at 17.0N, 86.0W at 18UTC. Ship highlights: 15 kt S and 1004 mb at 12Z at 17.8N, 82.8W (COA). Station highlights: no gales or low pressures. October 19: HWM loses the low in the Caribbean. HURDAT lists this system as a tropical storm at 21.0N, 80.4W at 12UTC. MWR's Tracks of Lows indicates a center with 1012mb at 25N, 75W (am) and at 25.5N, 72.5W (pm). Ship highlights: no gales or low pressures. Station highlights: no gales or low pressures. October 20: HWM analyzes a closed low of at most 1010 mb centered near 25.5N, 72W with a warm front extending eastward from the low and a cold front extending west-southwestward from the low. HURDAT lists this system as a tropical storm near 24.0N, 74.9W at 12UTC. MWR's Tracks of Lows indicates the center with 1007mb at 26N, 69.5W (am) and at 27N, 67W (pm). Ship highlights: 35 kt NE and 1014 mb at 12Z at 27.0N, 79.8W (COA). Three other gales of 35 kt. Station highlights: no gales or low pressures. “Two barometric depressions, apparently weak tropical disturbances in origin, appeared over the region of the Bahamas, the first between the 12th and 15th and the second about a week later. The first development produced no high winds so far as reports in hand indicate, but the second caused moderate to fresh gales on the 20th and 22d as it moved northeastward into the middle-western part of the Atlantic” (MWR). October 21: HWM analyzes an elongated, closed low of at most 1010 mb centered near 28N, 61W with a warm front extending eastward from the low and a cold front extending southwestward from the low. HURDAT lists this as a tropical storm at 28.7N, 64.8W at 12Z. MWR's Tracks of Lows indicates the center at 28N, 63W (am) and at 29.5N, 58.5W (pm). Ship highlights: 30kt W with 998mb at 27.4N, 67.0W at 10UTC (MWR); 45 kt N (MWR); 25 kt N and 1003 mb at 12Z at 27.9N, 62.1W (COA); 35 kt ENE and 1007 mb at 16Z at 30.5N, 60.5W (COA); 50 kt ENE and 1001 mb at 20Z at 30.5N, 61.5W (COA); 35 kt SW and 1004 mb at 21Z at 25.6N, 61.6W (MWR). October 22: HWM shows a frontal system with a pressure minimum of below 1000mb near 32N, 52W at 12UTC. HURDAT lists this as a tropical depression at 31.2N, 53.1W at 12Z. MWR's Tracks of Lows indicates the center with 997mb at 31N, 53W (am). Ship highlights: 45 kt SW and 998 mb at 12Z at 28.2N, 54.5W (COA); 50 kt SW and 999 mb at 13Z at 30.0N, 53.4W (MWR); 50 kt SSW at 19Z at 29.5N, 50.5W (COA). At least four other gales between 35-45 kt and at least seven other low pressures between 999-1003 mb. Station highlights: no gales or low pressures. HURDAT started this system originally at 18Z on 18 October as a 35 kt tropical storm at 17N, 86W. The recommendation by Perez et al. to begin the system as a tropical depression on the 16th and 17th was not implemented, as observations – while showing a distinct trough – do not show a closed low on those dates. Observations do indicate, however, that a closed low existed by 12Z on the 18th, so genesis is analyzed to have occurred six hours earlier than previously shown in HURDAT with a 12Z position of 17.2N, 85.5W. However, the cyclone is begun as a 30 kt tropical depression, and the 35 kt tropical storm intensity at 18Z on the 18th is unchanged from HURDAT. The cyclone traveled northeastward throughout its lifetime, crossing Cuba on the 19th, the Bahamas on the 20th, and accelerating to the central Atlantic on the 21st and 22nd. Track changes were minor (less than 2 degrees) from the 18th through 06Z on the 20th. The cyclone is analyzed to have made a Cuban landfall at 18Z on 19 October as a 40 kt tropical storm at 21.8N, 80.0W. The reason why the HURDAT intensity at 18Z on the 19th is increased from 35 to 40 kt is because the landfall time was changed due to the track changes. HURDAT originally showed a 40 kt intensity at the point before Cuban landfall, and no changes were made to this 40 kt intensity for Cuba. The cyclone was over Cuba until 22Z on the 19th. The analyzed intensity at 00Z on the 20th is 35 kt, showing that the storm weakened by 5 kt while over Cuba. Minor upward intensity adjustments of 5 kt are implemented at 18Z on the 19th and on the 20th from 06-18Z. A few 35 kt gales were observed on the 20th, and analyzed intensity is 40 kt. Major northeastward track adjustments of over 2 degrees are analyzed at 12 and 18Z on the 20th. The cyclone is analyzed to have become extratropical at 00Z on the 21st. HURDAT previously did not list this cyclone as ever having become extratropical, so an extratropical stage is added into HURDAT on the 21st and 22nd – this is a major change to HURDAT. Track adjustments on the 21st and 22nd were minor. However, the intensity was adjusted upward on the 21st and 22nd due to ship observations of winds as high as 50 kt and pressures as low as 997 mb. Major upward intensity revisions of 20 to 30 kt are implemented on 22 October from 06-18Z. A 55 kt intensity is analyzed from 18Z on the 21st through 18Z on the 22nd. No change is made to the timing or position of dissipation (18Z on 22 October at 31.6N 50.9W) as a 55 kt extratropical cyclone. ******************************************************************************* 1931 Storm 11 (new to HURDAT) – Added in 2012 25581 11/01/1931 M= 5 11 SNBR= 569 NOT NAMED XING=0 SSS=0 25581 11/01* 0 0 0 0* 0 0 0 0*175 835 30 0*176 838 30 0 25581 11/02*177 841 35 0*178 843 40 0*180 845 45 0*182 845 50 0 25581 11/03*183 844 50 0*184 842 50 0*185 840 50 0*184 841 50 0 25581 11/04*182 843 50 0*179 846 45 0*175 850 40 0*175 850 35 0 25581 11/05*176 847 35 0*178 844 30 0*180 840 30 0*182 837 25 0 25581 TS Evidence from HWM, COADS, and MWR indicate that a tropical storm, previously undocumented in HURDAT, meandered in the western Caribbean Sea from 1-5 November. October 28: HWM analyzes a closed low of at most 1010 mb centered near 11N, 82W. Ship/Land highlights: No gales or low pressures. October 29: HWM analyzes no features of interest in the Western Caribbean. Ship/Land highlights: No gales or low pressures. October 30: HWM analyzes a closed low of at most 1010 mb centered over Honduras near 15N, 86W. Ship/Land highlights: No gales or low pressures. October 31: HWM analyzes a closed low of at most 1010 mb centered over Nicaragua near 14N, 84W. Ship/Land highlights: No gales or low pressures. November 1: HWM analyzes a closed low of at most 1010 mb centered near 16N, 83W. Ship/Land highlights: No gales or low pressures. November 2: HWM analyzes a closed low of at most 1010 mb centered near 17N, 84W. Ship highlights: 45 kt N at 10 UTC 17.5N 86.5W (COA) and four additional 45 kt reports from the same ship (likely the San Blas); 35 kt NNW and 1012 mb at 13 UTC at 16.8N 85.5W (COA). No low pressures. Land highlights: No gales or low pressures. Regarding the intensity: "A mild disturbance over the western Caribbean Sea produced a distinctive cyclonic circulation which was reported of gale force on the 2nd by the Panamanian ship San Blas, but the disturbance failed to develop a definite center of low pressure" (MWR). November 3: HWM analyzes a closed low of at most 1010 mb centered near 17N, 82W. Ship highlights: 50 kt WNW at 06 UTC at 17.5N 87.5W (COA); 45 kt NW and 1015 mb at 00 UTC at 16.3N 86.7W (COA); 45 kt NW and 1014 mb at 01 UTC at 18.7N 85.3W (COA); 45 kt NW at 06 UTC at 20.0N 86.0W (COA); two other gales. No low pressures. Land highlights: No gales or low pressures. November 4: HWM analyzes a closed low of at most 1010 mb centered near 17N, 84W. Ship highlights: 35 kt SW and 1015 mb at 12 UTC at 15.8N 86.8W (COA); 35 kt NW and 1011 mb at 09 UTC and 10 UTC at 17.0N, 87.0W (MWR/COA); 35 kt WNW and 1011 mb at 12 UTC at 17.3N, 86.4W (HWM). A few other gales. No low pressures. Land highlights: No gales or low pressures. November 5: HWM analyzes a closed low of at most 1010 mb centered near 17N, 82W. Ship highlights: No gales or low pressures. Ship observations as well as quotes in MWR indicate that a tropical depression formed in the western Caribbean Sea on 1 November near Swan Island, became a tropical storm by the 2nd, and meandered very slowly westward through the 5th of November. Numerous gales were reported from the 2nd to the 4th. Observations during much of the system’s lifetime show that winds on the southeast side of the cyclone were light compared to the other quadrants, but there are enough observations to analyze a closed circulation. Additionally, the thermal structure was analyzed, which indicated relatively isothermal for the four days the system had tropical storm force winds. Since a closed circulation is analyzed along with numerous observations of gale force winds from at least five separate ships and the isothermal structure, this system is added to HURDAT. In general, these gale force winds were 75 to 200 nm from the center suggesting that the system did have some subtropical cyclone characteristics. The highest winds recorded on the 2nd were 45 kt and 50 kt winds were recorded on the 3rd. Winds as high as 40 kt were recorded on the 4th. It is noted that there may have been some funneling of winds and slightly cooler air along the east coast of Central America on the 2nd to the 4th in association with this system. However, a distinct minimum in wind speed occurred in the winds north of the system near the Yucatan Channel, western Cuba, and south Florida, suggesting that the cyclone was a separate entity producing (at least in part) the numerous tropical storm force winds. After the 4th, there were no more observations of gale force winds, and the cyclone is analyzed to have weakened to a tropical depression on 5 November before dissipating about 100 nmi east of the coastline at the border between Belize and Mexico’s Yucatan Peninsula. The peak analyzed intensity is 50 kt from 18Z on 2 November to 00Z on 4 November. This cyclone did not make any landfalls. ******************************************************************************* 1931 Storm 12 (new to HURDAT) – Added in 2012 25582 11/11/1931 M= 5 12 SNBR= 570 NOT NAMED XING=0 SSS=0 25582 11/11*118 0 0 0* 0 0 0 0*115 790 30 0*115 793 30 0 25582 11/12*115 795 30 0*116 797 30 0*117 800 30 0*118 802 30 0 25582 11/13*120 805 35 0*122 808 35 0*125 810 35 0*130 812 35 0 25582 11/14*136 814 40 0*143 817 40 0*150 820 45 0*155 824 45 0 25582 11/15*160 829 40 0*165 836 40 0*170 845 35 0*175 856 35 0 25582 11/16*180 869 35 0*185 884 30 0*190 900 25 0*195 918 25 0 25582 TS HWM, MWR and COADS indicate that a tropical storm, previous undocumented in HURDAT, occurred from 11-16 November in the western Caribbean Sea. November 6: HWM analyzes a closed low of at most 1010 mb centered near 14N, 81W. Ship/Land highlights: No gales or low pressures. November 7: HWM analyzes a closed low of at most 1010 mb centered near 12N, 80W. Ship/Land highlights: No gales or low pressures. November 8: HWM analyzes a closed low of at most 1005 mb centered near 12N, 78W. Ship highlights: 10 kt E and 1005 mb at 12 UTC at 12.3N, 76.1W (COA). No gales. No other low pressures. Land highlights: No gales or low pressures. November 9: HWM analyzes a closed low of at most 1005 mb centered near 11N, 77W. Ship/Land highlights: No gales or low pressures. Regarding the intensity: "Another gale was reported in the western Caribbean, and news dispatches reported extraordinary rains and storm damage in Honduras, but these appear to have been due to an intensification of the trade winds rather than to a true tropical disturbance" (MWR). November 10: HWM does not analyze a closed low on this day. Ship/Land highlights: No gales or low pressures. November 11: HWM does not analyze a closed low on this day. Ship/Land highlights: No gales or low pressures. November 12: HWM analyzes a trough of low pressure in the extreme southwestern Caribbean Sea near Panama. Ship highlights: 15 kt SE and 1003 mb at 12 UTC at 11.8N, 78.4W (HWM). No gales. No other low pressures. Land highlights: No gales or low pressures. November 13: HWM does not analyze a closed low on this day. Ship highlights: 15 kt SSE and 1005 mb at 09 UTC at 10.7N, 78.4W (COA); 10 kt E and 1005 mb at 21 UTC at 11.7N, 76.9W (COA). No gales. No other low pressures. Land highlights: No gales or low pressures. November 14: HWM analyzes an area of low pressure in the extreme southwestern Caribbean Sea near Costa Rica. Ship highlights: 35 kt ENE and 1012 mb at 11 UTC at 16.8N, 82.0W (COA); 45 kt E before 21 UTC at 15.6N, 81.2W (MWR); 30 kt E and 1005 mb at 21 UTC at 15.5N, 81.5W (COA). One other gale. No other low pressures. Land highlights: No gales or low pressures. November 15: HWM does not analyze a closed low on this day. Ship highlights: 30 kt ENE and 1005 mb at 22 UTC at 17.5N, 86.5W (COA). No gales. No other low pressures. Land highlights: No gales or low pressures. November 16: HWM does not analyze a closed low on this day. Ship/Land highlights: No gales or low pressures associated with this system. Observations indicate that an area of low pressure began to take shape on 6 November near 11.0N, 80.5W. This low moved little from 6 to 9 November, and a lack of observations on the 10th and 11th made it difficult to determine whether this low moved off to the northeast or whether went on to become the tropical cyclone on 11 November, which is the feature of interest discussed here. Either way, by 11-12 November, observations indicated a tropical cyclone formed in the southwestern Caribbean Sea. On the 13th, the cyclone began moving toward the northwest, and two gales were recorded on the 14th. In addition to these two gales, several low pressure observations (mostly 1003-1005 mb) were recorded between 12-15 November. Due to the analysis of a closed circulation along with two gale observations and several low pressure observations, this system is added to HURDAT. The cyclone is analyzed to have attained tropical storm intensity at 00Z on the 13th, and a peak intensity of 45 kt is analyzed from 12-18Z on the 14th. The cyclone passed a short distance northeast of the eastern tip of Honduras late on the 14th. Landfall is analyzed around 04Z on the 16th as a 35 kt tropical storm near the border between Belize and Mexico’s Yucatan Peninsula. The highest observed wind on the 15th (the day before landfall) was 30 kt, and the cyclone is analyzed to have weakened to a 35 kt tropical storm prior to landfall. After landfall, this cyclone weakened to a tropical depression and the final point is listed at 18Z on 16 November at 19.5N, 91.8W as a 25 kt tropical depression before a closed circulation was no longer indicated by observations. ******************************************************************************* 1931 Storm 13 (originally Storm 9) – Revised in 2012 25585 11/22/1931 M= 4 9 SNBR= 569 NOT NAMED XING=0 SSS=0 25585 11/22/1931 M= 4 13 SNBR= 569 NOT NAMED XING=0 SSS=0 ** 25590 11/22* 0 0 0 0*193 616 35 0*209 632 35 0*219 640 35 0 25590 11/22* 0 0 0 0*220 637 35 0*228 645 35 0*235 652 35 0 *** *** *** *** *** *** 25595 11/23*231 650 35 0*246 661 35 0*259 673 35 0*266 681 35 0 25595 11/23*243 659 35 0*251 667 35 0*259 675 40 0*266 687 45 0 *** *** *** *** *** ** *** ** 25600 11/24*273 689 35 0*280 702 40 0*287 719 40 0*289 728 40 0 25600 11/24*273 704 50 0*280 723 55 0*285 741 55 0*283 748 55 0 *** ** *** ** *** *** ** *** *** ** 25605 11/25*288 738 40 0*286 750 40 0*282 763 35 0*270 789 30 0 25605 11/25*280 752 50 0*277 755 40 0*274 758 35 0*271 762 30 0 *** *** ** *** *** *** *** *** *** 25610 TS Major track changes and minor intensity changes are analyzed for this tropical storm, originally storm #9. Evidence for these alterations comes from the Historical Weather Maps Series, the COADS ships database, and Monthly Weather Review. Nov 20: “On Friday [Nov 20] the weather was unsettled. Rain, thunder and lightning made their appearance” (The Antigua Magnet Nov 24. From Chenoweth). Nov 21: “Heavy rains on Saturday night [Nov 21] flooded a portion of the Union Experiment Station but fortunately the damage done is not serious. (in 3 hours, 3.50 inches of rain, and high tide coincided with the peak flow of the stream, causing the flood)” (Voice of St. Lucia Nov 26. from Chenoweth). Nov 22: HWM does not show a system. HURDAT begins this system as a tropical storm at 19.3N, 61.6W at 6UTC. MWR's Tracks of Lows indicates the center at 21N, 63W (am) and at 24N, 65W (pm). Ship highlights: 45kt ENE at 24.3N, 56.9W at 12UTC (COA); 45kt E with 1016mb at 26.5N, 55.5W at 0UTC (COA). Station highlights: no gales or low pressures. Nov 23: HWM shows signs of a wave axis between 20-30N and 67.5W at 12UTC. HURDAT has this system as a tropical storm near 25.9N, 67.3W at 12UTC. MWR's Tracks of Lows indicates the center with 1010mb at 26.5N, 68W (am) and at 28N, 69W (pm). Ship highlights: 35kt E with 1008mb at 29.5N, 67.5W at 20UTC (COA). Station highlights: no gales or low pressures. Nov 24: HWM does not show a low but indicates there might be one near 70W between 20N and 30N at 12UTC. HURDAT lists this system as a tropical storm at 28.7N, 71.9W at 12UTC. MWR's Tracks of Lows indicates the center with 1003mb at 29N, 72W (am) and at 28.5N, 83W (pm). Ship highlights: 50kt ESE at 31.2N, 70.3W after 12UTC (MWR); 50kt W at 26.3N, 75.3W after 17UTC (MWR); 25kt NNW with 998mb at 28.5N, 74.5W at 12UTC (COA); Station highlights: no gales or low pressures. Nov 25: HWM does not show a system. HURDAT has this system as a tropical storm centered near 28.2N, 76.3W at 12UTC. MWR's Tracks of Lows indicates the center with 1008mb at 28.5N, 76W only in the morning. Ship highlights: 35kt SW with 1004mb at 26.5N, 74.5W at 5UTC (COA). Station highlights: no gales or low pressures. A tropical storm formed north of the northernmost Leeward Islands on 22 November at 06Z (no change to the timing of genesis). The cyclone traveled northwestward from genesis until the 24th, when it turned westward and west-southwestward on the 25th north of the Bahamas and east of Florida. Observations indicate that the positions at 06-12Z on the 22nd need to be moved more than 2 degrees to the northwest of the previous HURDAT positions; thus major track changes are implemented at those times. Minor northwestward track adjustments are implemented from 18Z on the 22nd through 06Z on the 23rd. Significant westward track adjustments are implemented from 00Z on the 24th to 00Z on the 25th with a major track change at 12Z on the 24th. Finally, another major track change is made at the last 6-hourly point for this cyclone - 18Z on the 25th (an eastward adjustment). A peak intensity of 55 kt is analyzed on 24 November from 06-18Z based on two separate 50 kt ship observations. HURDAT previously listed a peak intensity of 40 kt from 06Z on the 24th to 06Z on the 25th. Minor upward intensity adjustments of 5 to 15 kt are implemented at all times from 12Z on the 23rd through 00Z on the 25th. The tropical storm is analyzed to have weakened to a tropical depression at 18Z on the 25th (no change), and no change is made to the timing of dissipation. Note: It is possible that this system could have been subtropical for some of its lifetime. ****************************************************************************** 1931 Additional Notes: There are no additional suspects of note.