000 AXNT20 KNHC 210606 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Oct 21 2023 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0605 UTC. ...SPECIAL FEATURES... The center of Hurricane Tammy, at 21/0600 UTC, is near 14.9N 60.3W. This position also is about 43 nm/80 km to the ENE of Martinique, and about 105 nm/195 km to the SE of Guadeloupe. Tammy is moving WNW, or 300 degrees, 05 knots. The estimated minimum central pressure is 991 mb. The maximum sustained wind speeds are 70 knots with gusts to 85 knots. The radius of hurricane-force winds is: within 20 nm of the center in the NE quadrant; within 0 nm of the center in the SE quadrant; within 0 nm of the center in the SW quadrant; and within 0 nm of the center in the NW quadrant. The radius tropical-storm force winds is: within 110 nm of the center in the NE quadrant; within 110 nm of the center in the SE quadrant; within 30 nm of the center in the SW quadrant; and within 80 nm of the center in the NW quadrant. The sea heights that are 12 feet or greater are: within 150 nm of the center in the NE quadrant; within 240 nm of the center in the SE quadrant; within 240 nm of the center in the SW quadrant; and within 270 nm of the center in the NW quadrant. The maximum sea heights are 24 feet. Precipitation: numerous strong is within 200 nm of the center in the SE quadrant. Scattered moderate to widely scattered strong is within 300 nm of the center in the NE quadrant. Please, consult bulletins and forecasts from your local weather office. Read the latest HIGH SEAS FORECAST, that is issued by the National Hurricane Center, at the website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, and the latest Tammy NHC Forecast/Advisory and Public Advisory, at www.hurricanes.gov, for more details. ...EASTERN ATLANTIC OCEAN DEVELOPING GALE-FORCE WINDS... The METEO-FRANCE forecasts consist of gale-force winds for the marine areas IRVING and MADEIRA. Please, refer to the following website, https://wwmiws.wmo.int, for details. ...MONSOON TROUGH/ITCZ... The monsoon trough is inland in Africa. The ITCZ starts at the coastal border of Senegal and Guinea-Bissau, and it continues to 06N24W 07N33W. The ITCZ is broken up by a 13N35W 09N40W surface trough. The ITCZ continues from 08N41W to 05N46W, and 05N52W. Precipitation: scattered to numerous strong is within 240 nm to the north of the second part of the ITCZ between 41W and 49W. Widely scattered moderate to isolated strong is within 240 nm to the north of the rest of the surface trough and the ITCZ. Widely scattered moderate to isolated strong is from 03N to 14N from the surface trough eastward. ...GULF OF MEXICO... A surface trough is along 22N93W 17N92W, in the SW corner of the area. Precipitation: isolated moderate is within 60 nm on either side of the surface trough. A surface ridge extends from a 24N96W 1014 mb high pressure center into the Straits of Florida. A stationary front extends from Georgia to central Texas. Slight seas, and moderate or slower wind speeds, span the area. High pressure from the northern Gulf into Georgia will shift SW through Sat, allowing a cold front to move into the NE Gulf, then slowly dissipate as it moves across the eastern Gulf into Sat night. Another cold front will follow, moving across the eastern Gulf Sun night through Mon, before stalling southeast of the region by Mon night into early Tue. Looking ahead, high pressure building in the wake of the front will support moderate to fresh E winds and building seas Sun night through mid week. ...CARIBBEAN SEA... A surface trough passes through 25N77W in the Bahamas, through Cuba near 22N78W, into the SW corner of the Caribbean Sea near 12N82W. Precipitation: isolated moderate to locally strong is elsewhere in the area that is from 70W westward. Upper level cyclonic wind flow is between 63W and Haiti. Precipitation: isolated moderate is from 70W eastward, away from Hurricane Tammy. The monsoon trough is along 10N from 74W in Colombia, beyond Costa Rica, and into the Pacific Ocean. Precipitation: scattered to numerous strong is within 200 nm to the south of the monsoon trough between 81W and 86W. The 24-hour rainfall totals in inches, for the period that ended at 21/0000 UTC, according to the MIATPTPAN, are: 1.51 in Merida in Mexico; 0.41 in Bermuda; and 0.16 in Guadeloupe. Moderate to fresh winds are within 380 nm to the west of Hurricane Tammy, from 13N/14N northward. Moderate or slower wind speeds cover the rest of the area. Moderate seas are in the NE corner of the eastern one-third of the Caribbean Sea. Slight seas are in the rest of the area. Hurricane Tammy is near 14.7N 60.2W at 11 PM EDT, and is moving west-northwest at 8 kt. Maximum sustained winds are 70 kt with gusts to 85 kt, and the minimum central pressure is 992 mb. Tammy will move to 15.8N 61.0W Sat morning, 17.3N 62.0W Sat evening, then reach 18.8N 63.0W Sun morning. Hurricane Tammy will be near 20.0N 63.8W Sun evening, 21.4N 64.3W Mon morning, and 22.4N 64.0W Mon evening. Tammy will change little in intensity as it moves to farther N of the Leeward Islands late Tue. Elsewhere, a trough will persist over the northwest Caribbean into Sat. Looking ahead, a weak cold front will move into the northwest Caribbean by late Mon, then stall and weaken from eastern Cuba to northern Belize Tue. ...ATLANTIC OCEAN... A surface trough is along 31N71W, to 25N77W in the Bahamas, through Cuba near 22N78W, into the SW corner of the Caribbean Sea near 12N82W. Precipitation: widely scattered moderate to isolated strong is from 250 nm to 350 nm to the SSE of the surface trough. W-to-SW strong to near gale-force winds are from 28N northward from 76W westward. A frontal boundary passes through the Carolinas to Georgia. Strong southerly winds are within 480 nm to the SSE of the surface trough from 26N northward. Strong SE winds are from 17N to 20N between 60W and 65W. Fresh winds are from the ITCZ to the line 30N57W 27N50W between 30W and 57W. Mostly fresh to moderate winds are from 30W eastward. A cold front passes through the coastal plains of Western Sahara near 23N16W, to 24N38W. Precipitation: broken to overcast multilayered clouds, and isolated moderate, are within 60 nm on either side of the cold front. Moderate to rough seas are from the cold front northward. The rough seas are mostly from 28N northward from 30W eastward. Mostly fresh to some moderate winds are from the cold front southward to the ITCZ. Moderate seas are from the cold front northward. A surface ridge extends from a 1025 mb high pressure center that is near 32N46W, to the eastern part of the Dominican Republic. Hurricane Tammy is near 14.7N 60.2W at 11 PM EDT, and is moving west-northwest at 8 kt. Maximum sustained winds are 70 kt with gusts to 85 kt, and the minimum central pressure is 992 mb. Tammy will move to 15.8N 61.0W Sat morning, 17.3N 62.0W Sat evening, then reach 18.8N 63.0W Sun morning. Hurricane Tammy will be near 20.0N 63.8W Sun evening, 21.4N 64.3W Mon morning, and 22.4N 64.0W Mon evening. Tammy will change little in intensity as it moves to farther N of the Leeward Islands late Tue. Farther west, a weak cold front will move off the northeast Florida coast Sat morning, then weaken as it moves eastward over the waters north of 27N, before stalling and dissipating east of Bermuda early next week. A second front will follow, moving off the northeast Florida coast late Sun, reach from Bermuda to West Palm Beach, Florida by early Mon. $$ mt