000 AXNT20 KNHC 270008 AAA TWDAT Tropical Weather Discussion...Updated NWS National Hurricane Center Miami FL 0005 UTC Fri Oct 27 2023 Updated for Special Features 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Storm Force Wind Warning Northwestern Atlantic (Post-Tropical Cyclone Tammy): Post-Tropical Cyclone Tammy is centered near 31.0N 59.5W at 26/1800 UTC. Estimated minimum central pressure is 977 mb. Gale to strong gale winds, reaching hurricane force closer to the center of the system N of the area, and seas of 22 to 25 ft seas are noted from 29N to 31N between 57W and 63W. Scattered moderate and isolated strong convection is noted from 28N to 31N between 58W and 66W. This system is forecast to become separated from the front during the next day or so, and environmental conditions are forecast to become more conducive for the low to regain tropical characteristics while it meanders over the northwestern Atlantic to the east of Bermuda through Saturday. Regardless of tropical redevelopment, the system is likely to bring gusty winds and heavy rainfall to Bermuda during the next couple of days. Interests on Bermuda should monitor the progress of this system. This system has a medium chance of tropical cyclone formation through the next 48 hours. Please read the latest NHC Tropical Weather Outlook at www.hurricanes.gov and the latest HIGH SEAS FORECAST at www.hurricanes.gov/marine for more details. Western Atlantic Rough Seas: Swell generated from Tammy combined with swell generated from strong gradient flow that developed west of Tammy is supporting a large area of 12 ft seas over the western Atlantic waters N of 24N between 55W and 70W. Mariners should either avoid this region or use extreme caution in this area, depending on your vessel type and cargo. Hazardous surf and rip currents are also anticipated along the coast of central Florida, the Bahamas, Greater Antilles and the northern Leeward Islands. The seas of 12 ft or greater will generally continue over the waters N of 23N between 55W and 71W before subsiding early this weekend. 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 Offshore Waters Forecast at https://www.nhc.noaa.gov/marine/offshores.php for more details. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic off the coast of Africa near 12.5N16.5W to 08.5N20W. It then transitions to ITCZ and extends to near 09N37W. Scattered moderate convection is noted from 06N to 14N between 20W and 35W. ...GULF OF MEXICO... A ridge of high pressure extends across the Gulf coast states. Fresh to strong winds prevail over the Florida Straits with moderate winds noted elsewhere over the Gulf waters. Seas are in the 7-8 ft range over the Gulf of California and 5-7 ft elsewhere. For the forecast, high pressure centered north of the area will continue to support moderate to fresh winds, locally strong in the eastern 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. The next cold front is forecast to reach the NW Gulf on Mon. This front could bring gale force winds and building seas over the western Gulf early next week. ...CARIBBEAN SEA... An upper level trough extends across the waters from Hispaniola to the SW Caribbean. This trough is helping to support active convection over much of the Caribbean waters S of 18N. Fresh to strong winds, and seas of 5-7 ft, are noted over the waters N of 15N and W of 70W. Light to gentle winds, and seas of 3-5 ft are noted elsewhere. For the forecast, strong high pressure N of the area will continue to support fresh to occasionally strong NE to E winds in the NW and north- central Caribbean, including the Windward Passage through the week. Gentle winds are expected elsewhere. ...ATLANTIC OCEAN... Please read the Special Features section above for more on a Storm Warning associated with Post-Tropical Cyclone Tammy southeast of Bermuda, and rough seas across the western Atlantic. A cold front extends from 31N53W to 23N57W. Scattered moderate and isolated strong convection is noted within 90 nm east of the front. A surface trough is found from 17N46W to 10N47W. Scattered moderate convection is noted within 120 nm east of the trough axis. Fresh to strong winds are noted west of 65W, with fresh to near gale winds elsewhere south of Tammy N of 26N between 55W and 65W. Gentle to moderate winds are noted elsewhere. Aside from the area of 12 ft seas, seas of 8-11 ft are noted N of 19N and W of 50W. Seas of 5-7 ft are elsewhere over the discussion waters. For the forecast W of 55W, strong extratropical cyclone (former Tammy) associated with an occluded front is located near 31N59W or a few hundred miles east-southeast of Bermuda. There is a possibility that this system could regain tropical or subtropical characteristics while it meanders over the northwestern Atlantic through early next week. High winds and hazardous seas are still present, and a Storm Warning remains in effect for portions of the area SE of Bermuda. Gales will continue into Fri. The gradient between former Tammy and high pressure N of the area will continue to support strong to near gale-fore NE winds and very rough seas well W of former Tammy across much of the forecast area through the week. $$ AL/jrl