000 AXNT20 KNHC 112254 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Dec 11 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2230 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Sierra Leone at 09N13W to 07N15W, where latest scatterometer data indicates that it transitions to the ITCZ to 04N30W and to 05N42W. Scattered moderate convection observed within 05N-08N between 23W-30W. GULF OF MEXICO... A few showers are active across the Texas coastal waters, ahead of an approaching cold front currently moving through the Southern Plains. These showers are being supported in part by moisture delivered by fresh southerly flow over much of the northwest Gulf of Mexico, along with 5 to 7 ft seas. Broad, deep-layer ridging is in place across the remainder of the basin anchored by 1022 mb high pressure over central Florida. A recent scatterometer satellite pass indicated moderate to fresh SE flow and 4 to 6 ft seas in the Bay of Campeche, between the ridge and lower pressure over eastern Mexico. Gentle to moderate SE breezes and 2 to 4 ft seas persist elsewhere across the Gulf, with generally fair weather. For the forecast: The high pressure over central Florida will shift northeast tonight, as southerly winds increase across across the western Gulf in advance of the approaching cold front. This weak front will move into the NW Gulf Sat then lift back N of the area Sun. Another cold front will move into the Gulf Sun night, and will reach from the Florida Panhandle to Bay of Campeche, with strong winds in its wake. Gales are forecast over portions of the western and southwestern Gulf Mon and Mon evening offshore Mexico from Tampico to Veracruz. CARIBBEAN SEA... A broad upper trough reaches from the western Atlantic over the southern Bahamas and eastern Cuba, to just north of Jamaica. This is supporting a few showers from Grand Cayman Island to Jamaica. Farther east, isolated showers are noted over the Windward Islands, in moderate easterly trade flow. Earlier scatterometer satellite data indicated fresh to strong NE to E winds off Colombia, with moderate to fresh trade winds elsewhere over the central Caribbean. Seas are estimated to be 6 to 9 ft off Colombia, and 4 to 6 ft seas elsewhere over the eastern and central Caribbean. Gentle to moderate NE to E winds are evident over the northwest Caribbean, with 3 to 5 ft seas. For the forecast, strong NE winds will pulse nightly into Mon along the Colombian coast. Weak high pressure will dominate the basin well into next week. ATLANTIC OCEAN... A weakening and stalling frontal boundary extends from 32N43W to eastern Dominican Republic. Scattered showers and thunderstorms are active along the boundary off the north coast of Hispaniola, ahead of a mid to upper level trough just to the west. A few showers are also noted along the front from 25N to 28N between 48W and 52W. 1027 mb high pressure is centered north of Bermuda. Moderate to fresh NE winds are noted within 120 nm along the front south of 27N, gentle to moderate east winds evident west of the front. Seas are 3 to 5 ft in open waters east of 70W, 5 to 7 ft between 60W and 70W north of 20N, and 7 to 9 ft elsewhere west of the front. For the forecast for waters west of 65W, the front will dissipate through tonight. The high pressure will dominate waters north of this front, bringing fresh to strong NE to E winds across NE waters tonight through Sat night. A cold front will move off the Florida coast Mon night, with some strong SW winds ahead of the front, mainly north of 28N. Elsewhere farther east, 1027 mb high pressure is centered over the eastern Atlantic between the Canary and Azores Islands is supporting fresh to strong NE winds off the coast of Morocco, and moderate to fresh trades elsewhere east of 50W, with 6 to 9 ft seas in a broad mix of swell. Gentle to moderate trades and 5 to 7 ft seas east of the Windward and Leeward Islands to 50W due to a surface trough along 53W from 10N to 22N. $$ Christensen