000 AXNT20 KNHC 071745 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Dec 7 2022 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 1200 UTC surface analysis and satellite imagery through 1600 UTC. ...SPECIAL FEATURES... Central Atlantic Storm Warning: A large non-tropical area of 986 mb low pressure with peak winds of 55 kt and highest seas of 34 ft is located about 785 NM northeast of the northern Leeward Islands, near 28N54W. The ASCAT scatterometer at 1318Z partially observed the low and reported a peak wind of 48 kt near 29.5N 56W. Highest observed seas thus far are 25 ft from an altimeter at 0810Z near 31N51W. The low has an occluded front extending from the low's center eastward to 48W, a warm front extending from 30N47W to 29N38W, and a cold front extending from 30N47W to 25N40W. Numerous moderate and isolated strong convection is observed north of 29N between 40W-53W and north of 25N between 30W-40W. These showers and thunderstorms have become somewhat better organized this morning. Environmental conditions appear marginally conducive for development and a subtropical or tropical storm could form within the next day or so. By Friday, the low will move northeastward over cooler waters and interact with a mid- latitude trough, limiting the chance for additional subtropical or tropical development of the system. Regardless of development, winds on the northern and western portions of this low will be storm force through tonight. Gales will then continue in NE waters through Thu. Overall, there is a medium chance of subtropical or tropical development within the next 48 hours. More information about this system, including the associated storm warning, can be found in the Offshore Zone Forecasts issued by NHC at: http://www.nhc.noaa.gov/text/MIAOFFNT3.shtml and in the High Seas Forecasts issued by the National Weather Service at: http://www.nhc.noaa.gov/text/MIAHSFAT2.shtml. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea-Bissau near 11N15W to 08N17W. The ITCZ continues from 07N18W to 05N44W and again from 09N52W to 09N60W. Scattered moderate and isolated strong convection is noted from 03N-07N between 20W-43W and from 07N-10N wests of 55W. GULF OF MEXICO... A 1027 mb surface high pressure is centered over NE Florida with gentle to moderate winds prevailing across the Gulf. Seas are 1- 3 ft over the NE half of the Gulf and 4-6 ft over the SW half. Patchy fog is present within 60 NM of the Texas coast. No significant deep convection is occurring over the Gulf of Mexico today. For the forecast, the high pressure centered across the NE Gulf will meander about the area through the weekend. Moderate to fresh return flow will prevail W of 92W through tonight, then diminish through Sun night. CARIBBEAN SEA... The pressure gradient between the High over NE Florida and lower pressure over N South America is contributing toward moderate to fresh E to NE trades today in the central and W Caribbean. In the E Caribbean, gentle N winds are present. Seas in the central and W Caribbean are 4-6 ft and seas in the E Caribbean 2-4 ft except 4-6 ft of N swell through the Mona and Anegada Passages. For the forecast, deepening low pressure across the central Atlantic during the next few days will maintain NE winds across much of the basin, and fresh to locally strong NE winds through the Caribbean Passages, in the lees of the Greater Antilles, and offshore Colombia into Fri. Large NE swell across the central Atlantic will move through the Caribbean Passages and Tropical Atlantic waters into the weekend, with highest seas today into Fri night. ATLANTIC OCEAN... Please read the Special Features section above for details on a storm force wind producing low pressure several hundred nautical miles northeast of the northern Leeward Islands that has a potential for tropical or subtropical development over the next 48 hours. The powerful and strengthening low pressure in the central subtropical Atlantic is dominating weather across much of the basin. Strong winds or higher, rotating counter-clockwise around the low, are present N of 22N between 47W-65W. Fresh winds then extend south to 18N, west to 72W, and east to 40W. Elsewhere winds are moderate or weaker. The low pressure is contributing toward 8 ft or greater seas everywhere north of 18N between 35W- 75W. Farther northeast at 40N22W, a 991 mb low is forcing N swell of at least 8 ft down to 25N between 20W-32W. A cold front from this low enters our waters near 31N15W southwestward to 27N20W, and then transitions to a stationary front from 27N20W to 24N30W to 28N37W. Scattered moderate convection is noted from 25N-31N between 28W-36W. For the forecast for areas W of 55W away from the large non- tropical low, large long-period north to northeast swell will impact the Atlantic waters and Caribbean Passages between the southeastern Bahamas and the E Caribbean producing high seas into the weekend, with large E swell reaching the Florida offshore waters N of 26N early Fri through Sat. $$ LANDSEA