000 AXNT20 KNHC 241049 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue Oct 24 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 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...SPECIAL FEATURES... Hurricane Tammy is centered near 23.7N 62.8W at 24/0900 UTC or 530 nm SSE of Bermuda, moving NE at 8 kt. Estimated minimum central pressure is 987 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. Peak seas near the center are estimated at 27 ft. Numerous strong convection is seen within 180 nm mainly N and E of the center. A northeastward motion is expected to continue for the next day or two, following by a turn to the north. Some slight strengthening is forecast over the next 48 hours before weakening commences and Tammy begins to transition into a post-tropical cyclone. Swells generated by Tammy will continue to affect portions of the Leeward Islands, the British and U.S. Virgin Islands, and Puerto Rico during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please read the latest HIGH SEAS FORECAST 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. Western Atlantic Very Rough Seas: High pressure will move off the east coast of the United States, and build north of the forecast area through midweek. The pressure gradient will tighten between Hurricane Tammy and the area of building high pressure. The tightening pressure gradient will help to develop a very large area of strong to near-gale force NE winds and very rough seas of 12 to 17 ft across much of the area from 23N to 31N, between the east coast of Florida and 60W, starting this afternoon and continuing through Friday. Mariners should either seek to avoid this region, or use extreme caution in this area, depending on your vessel type and cargo. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the coast of west Africa near Guinea-Bissau from 10N15W to 06N21W to 06N26W. The ITCZ extends from 06N26W to 08N35W, then continues west of a surface trough from 09N41W to 09N48W to 13N52W. A surface trough is analyzed from 12N37W to 09N37W to 07N47W. Scattered moderate convection is near the monsoon trough from 06N to 10N between 22W and 25W. Scattered moderate to isolated strong convection associated with the ITCZ and surface trough are impacting areas from 07N to 12N between 35W and 50W. ...GULF OF MEXICO... High pressure centered over the SE U.S. is dominating the Gulf of Mexico, bringing dry conditions and fresh E winds to the basin. Little to no shower activity is noted across the basin currently. A broad surface ridge dominates the Gulf. Moderate to fresh SE winds and seas of 4 to 6 ft seas are seen over the western Gulf. Moderate E winds and 2-4 ft seas are over the SE Gulf. The northeast Gulf is experiencing gentle NE to E winds and 1-3 ft seas. Seas have increased to 4 to 7 ft. For the forecast, high pressure building north of the area will lead to increasing winds early this week, with fresh to locally strong E winds and building seas through Thu night. ...CARIBBEAN SEA... Tropical Depression Twenty-One has moved inland into Nicaragua early this morning and is near 13.1N 84.0W at 5 AM EDT. It is moving farther inland, northwest at 5 kt. Maximum sustained winds are 25 kt with gusts to 35 kt, and the minimum central pressure is 1007 mb. Twenty-One will become a remnant low and move to 13.2N 84.8W this afternoon, and dissipate Wed morning. Outside of TD Twenty-One, Scattered showers and tstorms are noted across the NW Caribbean, west of 76W. Moderate to locally fresh NE winds are present in the NW Caribbean and Windward Passage, with seas 3 to 6 ft. Elsewhere, winds are light to gentle with 1 to 3 ft seas. The exception is in the Mona and Anegada Passages, where swell from distant Hurricane Tammy is causing seas of 4 to 6 ft. For the forecast, Fresh to occasionally strong winds will prevail in the lee of Cuba and in the Windward Passage through the week. Winds will briefly increase to fresh to strong south of Hispaniola Wed night and Thu. ...ATLANTIC OCEAN... Please read the Special Features section at the beginning about Hurricane Tammy. A dissipating stationary front extends southwestward from near 31N61W to the SE Bahamas to eastern Cuba. Convection associated with this boundary has diminished overnight. Elsewhere west of 60W, outside of the area being affected by Tammy, winds are fresh to locally strong out of the NE with seas of 6 to 9 ft. A large dome of 1022 mb high pressure near 32N33W is providing gentle to moderate winds across the eastern Atlantic, east of 55W. Seas range from 4 to 7 ft over this area. For the forecast W of 55W, Hurricane Tammy is near 23.7N 62.8W at 5 AM EDT, and is moving northeast at 8 kt. Maximum sustained winds are 65 kt with gusts to 80 kt, and the minimum central pressure is 987 mb. Tammy will move to 24.5N 61.8W this afternoon, 25.9N 60.3W Wed morning, and 27.9N 59.0W Wed afternoon. Hurricane Tammy will reach 29.5N 58.9W Thu morning, then become extratropical near 31.0N 59.7W Thu afternoon. Tammy will be near 31.7N 60.9W Fri morning. A slow-moving cold front currently from near 31N63W to the central Bahamas will gradually stall tonight then dissipate by Wed. The pressure gradient between this front, Tammy, and high pressure building in off the east coast of the United States will lead to the development of a broad area of NE winds and rough seas across much of the area west of the frontal boundary Tue through the week. $$ KONARIK