000 AXNT20 KNHC 261004 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Oct 26 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 0930 UTC. ...SPECIAL FEATURES... Hurricane Force Wind Warning: Tammy became extratropical early this morning. Post-Tropical Cyclone Tammy is centered near 30.5N 58.4W at 26/0900 UTC or 340 nm ESE of Bermuda, moving N at 10 kt. Estimated minimum central pressure is 973 mb. Maximum sustained wind speed is 75 kt with gusts to 90 kt. Peak seas near the center are estimated at 32 ft. Numerous strong convection is noted within 210 nm E semicircle and 60 nm W semicircle. Tammy is forecast to turn NW and slow down over the next 36 hours or so. Although Tammy is a powerful post-tropical cyclone, with hurricane force winds, weakening is anticipated over the next few days. Despite Tammy no longer being tropical, high winds and hazardous seas are still present, and a Hurricane Force Wind Warning is now in effect for portions of the area SE of Bermuda. Hurricane Force winds are expected today, with Storm conditions tonight. Gales will continue into Fri. Swell will continue to affect portions of Bermuda, the northern Leeward Islands, the British and U.S. Virgin Islands, and Puerto Rico during the next couple of 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: A very tight pressure gradient between strong high pressure of 1028 mb centered over the east coast of North Carolina and Tammy will continue to support a large area of strong to near-gale force NE winds and very rough seas of 12 to 22 ft across much of the area from 22N to 31N, between the east coast of Florida and 60W, through Friday. Mariners should either seek to avoid this region, or use extreme caution in this area, depending on your vessel type and cargo. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Guinea near 11N15W, then continues westward to near 06N33W. The ITCZ extends from 06N33W to 08N46W, then continues west of a surface trough from 09N51W to 12N60W. The surface trough extends from 07N49W to 14N47W. Scattered moderate convection is noted from 03N to 13N east of 34W and from 10N to 16N between 42W and 49W. ...GULF OF MEXICO... A strong high pressure of 1028 mb centered over the east coast of North Carolina extends a broad ridge across the Gulf of Mexico bringing dry conditions. Fresh east to southeast winds and 6 to 8 ft seas prevail across the Gulf. The strongest winds and roughest seas are in the E and SE Gulf and Straits of Florida, with fresh to strong winds and seas of 7 to 9 ft. For the forecast, the high pressure centered north of the area will support moderate to fresh winds, locally strong in the E Gulf, through the remainder of the week. Mainly gentle NE winds are expected this weekend as the pressure gradient weakens and high pressure settles over the region. A cold front may move off the Texas coast for the start of next week. ...CARIBBEAN SEA... Divergence aloft combined with a weak surface trough is leading scattered moderate convection across the central and eastern Caribbean Sea from 14N to 19N between 65W and 80W, including portions southern Hispaniola and Puerto Rico.Scattered moderate to strong convection is along the N coast of NW Venezuela and NE Colombia. Scattered moderate convection is also noted in the SW Caribbean, off the coast of Costa Rica and Nicaragua. Strong high pressure over the east coast of North Carolina is leading to a very strong fetch of NE winds and rough seas over the Atlantic, to the north of the Caribbean Sea. To an extent, these conditions are affecting the northern Caribbean, north of 15.5N and west of 67W, where fresh to locally strong NE winds and 5 to 7 ft seas prevail, including in the Mona and Windward Passages, as well as south of Cuba and across the NW Caribbean. To the south of 16N, gentle or lighter trades and 1 to 3 ft seas prevail. For the forecast, fresh to occasionally strong winds will prevail in the NW and north-central Caribbean through the week. Gentle winds will prevail elsewhere. ...ATLANTIC OCEAN... Please read the Special Features section at the beginning about a Hurricane Force Wind Warning where now post-tropical cyclone Tammy is impacting the area as well as associated rough seas that extend well SW of Tammy and are impacting a large portion of the western Atlantic, including waters offshore and E of the Bahamas. Aside from the impacts depicted in the Special Features section, to the E of 50W, high pressure of 1024 mb centered south of the Azores near 32N29W is dominant. Mainly moderate winds prevail across the basin between 25W and 50W with seas 5 to 7 ft. Fresh NE winds are occurring offshore Africa between the Cabo Verde and Canary Islands. For the forecast W of 55W, despite Tammy no longer being tropical, high winds and hazardous seas are still present, and a Hurricane Force Wind Warning is now in effect for portions of the area SE of Bermuda. Hurricane Force winds are expected today, with Storm conditions tonight. Gales will continue into Fri. The gradient between Tammy and high pressure building NW of the area will continue to support strong to near gale-fore NE winds and very rough seas well W of Tammy across much of the area through the week. $$ KONARIK