271 AXNT20 KNHC 151723 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue Dec 15 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 1715 UTC. ...SPECIAL FEATURES... Gulf of Mexico Developing Gale: A cold front will move into the NW Gulf early tonight and cross the basin Wed through Thursday. Behind the front, brief gales are expected offshore of Veracruz on Wednesday afternoon. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the west coast of Africa near 09N13W and continues to 06N16W. The ITCZ begins near 06N16W and continues to 04N30W to 04N40W to the coast of N Brazil near 00N50W. Widely scattered moderate convection is from 02N-09N between Africa and 23W, and from 01N-09N between 00W-45W. GULF OF MEXICO... As of 1500 UTC, a 1012 mb low is over the NW Gulf of Mexico near 28N97W. A forming warm front is along the Texas coast from 29N93W to the surface low. Radar imagery shows scattered showers within 90 nm of the front. Elsewhere, a quasi-stationary front is over S Florida and the SE Gulf of Mexico from Fort Pierce Florida to to Port Charlotte Florida to the SE Gulf near 24N88W. A prefrontal trough is over S Florida from Homestead Florida to the SE Gulf near 23N87W. Broken low clouds are south of the trough. Mainly gentle winds prevail across the remainder of the basin. Seas in the Bay of Campeche and far SW Gulf are still 7-10 ft in north swell and are expected to subside to 6-8 ft today. A cold front will move into the NW Gulf tonight and cross the basin through Thu, and will bring brief gales offshore Veracruz Wed. Winds and seas will diminish through Fri as high pressure builds across the northern Gulf in the wake of this front. Another front will move into the northwest Gulf by Sat night. CARIBBEAN SEA... A mid to upper level ridge covers the western two-thirds of the Caribbean, leading to subsidence, dry air and mainly fair weather across the entire basin. Weakening high pressure north of the area is supporting gentle to moderate trade winds across the basin. Recent ASCAT data showed fresh trades confined to the south-central Caribbean, south of the 14N between 70W-78W. Seas of 2-4 ft prevail over the eastern and NW Caribbean, while 4-7 ft seas cover the area from the central to the SW basin. By Wed, high pressure will begin to re-strengthen to the north, and tradewinds offshore of Colombia will begin to pulse to strong each night through Sat night. A weakening cold front will move slowly SE across the Yucatan Channel and NW Caribbean Thu night through Fri before dissipating. Strong high pressure north of the front will produce fresh to strong NE tradewinds across much of the area Fri and Sat. ATLANTIC OCEAN... A cold front extends from 31N68W to Fort Pierce Florida. Scattered showers are within 120 nm of the front. Fresh winds are noted on both sides of the front north of 28N, with strong northerly winds beginning to cross 31N. A 1014 mb low is over the central Atlantic near 22N59W. A surface trough extends from 28N55W to the low center to 18N62W. Scattered moderate convection is east of the trough from 20N-28N between 49W-55W mostly due to upper level diffluence. A 1026 mb high is centered over the E Atlantic near 31N35W producing fair weather. The W Atlantic cold front will sweep eastward across the waters north of 27N through Wed. Meanwhile, a deep layer trough will remain nearly stationary along about 57W-58W through Tue before drifting westward and weakening tonight through Thu. The next cold front will move into the NW waters Wed night then slide slowly SE and reach from near Bermuda through the NW Bahamas to W Cuba Fri morning, then drift southeast of the area through late Sat. Fresh to strong southwesterly winds will be ahead of the front in the western Atlantic. $$ MRF/CTM