000 AXNT20 KNHC 111806 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 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 1200 UTC surface analysis and satellite imagery through 1745 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 04N27W and to 04N44W. Scattered moderate to isolated strong convection is seen within 120 nm north of the trough axis between 15W-18W. Scattered moderate convection is within 210 nm north of the ITCZ between 28W-32W, within 60 nm south of the trough axis between 15W-18W and also between 26W-28W and between 28W-31W. GULF OF MEXICO... Broad upper-level anticyclonic flow covers the basin, with the associated ridge axis extending from 32N88W to the Yucatan Peninsula. Associated table sinking air covers the far eastern section of the Gulf. A high pressure center of 1023 mb is centered over north-central florida with a ridge extending west- southwestward to 27N87W and to near 26N92W. A surface trough extends along the Mexican coast from near Tampico south- southeastward along the coast to near Veracruz. Fresh to locally strong southerly winds prevail across the western Gulf west of 94W, from near Veracruz to the central Texas coast. Seas are in the range of 4-7 ft across the Gulf, except for lower seas of 3-4 ft in the eastern and central Gulf. As for the forecast: The high pressure center over north-central Florida will shift northeastward through Friday, allowing fresh to locally strong southerly winds to expand across the western Gulf of Mexico in advance of the next approaching cold front. This front will move into the NW Gulf late Sun, then extend from the Florida panhandle to the Bay of Campeche Mon. Strong northwest to north winds will follow in behind the front. Gale conditions are likely Mon night offshore Mexico from Tampico to Veracruz. CARIBBEAN SEA... The previous analyzed stationary front that was analyzed across the central Caribbean has dissipated. A tight enough gradient in place is allowing for mainly fresh northeast winds to exist over the northwestern and western Caribbean waters. Fresh to strong northeast winds, as were highlighted by a morning ASCAT pass, are over the far south-central Caribbean to along the coast of Colombia. These winds will pulse at night through early next week. Gentle to moderate trades exist elsewhere across the basin. Seas are in the range of 4-7 ft, except for higher seas of 6-9 ft in the far south-central Caribbean to near the coast of Colombia. Broken to overcast low and mid-level clouds with isolated showers are seen across the Windward Passage and within 210 nm of the coasts of Nicaragua and Costa Rica. Similar clouds with isolated showers are over eastern Honduras and over the northern and central sections of Nicaragua. Scattered to broken low and mid- level clouds are over the majority of the island of Hispaniola. Scattered showers and isolated thunderstorms are possible with these clouds. Otherwise, patches of broken low and mid-level clouds with isolated showers are moving westward in the trade wind flow north of 15N and also south of 15N between 64W-69W. As for the forecast: Weak high pressure will remain over the area well into next week. Weakening high pressure across the western Atlantic Mon and Tue will induce a considerable diminishing of winds and seas area wide. ATLANTIC OCEAN... A weakening cold front extends from near 32N47W to 27N52W, then transitions to a stationary front to Hispaniola near 19N70W. Two broad surface ridges are on either side of this frontal system. Scattered moderate convection is seen within 90 nm SE of the front between 56W an 66W, while scattered moderate isolated strong convection is within 240 nm SE of the front to the north of 24N. Deep-layer low pressure centered near 22N44W is supporting scattered moderate convection from 18N to 24N between 42W and 48W. Elsewhere, a broad surface ridge is centered on a 1030 mb high near 33N26W, while a ridge west of the front is centered on a 1026 mb high near 36N70W. A weak trough is just along the Florida coast from near 28N80W to 26N80W. Isolated showers are near it. As for the forecast: The weakening stationary will dissipate tonight. A high pressure ridge will dominate waters north of this front, bringing fresh to strong northeast to east winds across northern waters this weekend. A cold front will move off the FLorida coast Mon night, with some strong southwest winds ahead of the front, mainly N of 27N. $$ Aguirre