000 AXNT20 KNHC 171039 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Dec 17 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border areas of Sierra Leone near 07.5N13W to 05N14W to 04.5N17W. The ITCZ continues from 04.5N17W to 04N27W to the Equator along 35W to 01S41W. Scattered to locally numerous strong convection is noted from 02.5N to 10N between 07N-22N. Scattered moderate isolated strong convection is from 02N to 07N between 22W-40W, and from 02.5N to 11N between 40W-58W. GULF OF MEXICO... Strong upper level SW wind flow covers the entire Gulf of Mexico and is producing a very progressive upper level pattern across the southern U.S. At the surface, a cold front extends from near Sarasota, Florida to near 23N88W then become stationary to the central Bay of Campeche near 18N94W. A 1025 mb high is over eastern Texas and is driving strong northerly winds behind the front south of 22N and west of 90W, where seas are still 8-11 ft in north swell. Broken to overcast multilayered clouds and widely scattered moderate showers are north of the front to 24N and west of 85W. A cluster of moderate tstms is along the front south of 19.5N to just inland along the Mexican coast. Moderate NW to N winds prevail elsewhere behind the front. Strong northerly winds will continue north of the front across the Bay of Campeche through Fri morning before diminishing. High pressure will shift ENE across the Gulf coast states Fri and Sat to produce fresh to locally strong E to SE winds across the basin. The next cold front will move into the northwest Gulf by Sat evening and move slowly SE through Mon, reaching the Florida Panhandle to the SW Gulf. CARIBBEAN SEA... Sinking air in the middle atmosphere dominates most of the Caribbean, between an upper level ridge over NW portions and a deep layered trough extending across the NE Caribbean. This is producing very stable conditions across most of the basin, except for isolated clusters of moderate convection across the Gulf of Honduras. The monsoon trough is along 08N/11N from 73W in N Colombia, beyond Panama and Costa Rica. Scattered moderate isolated strong convection is over SW portions south of 10N. Weak high pressure northeast of the Bahamas will begin to strengthen today, which will freshen tradewinds across most of the basin. Winds near Colombia will pulse to strong each night through Sat night. The weakening cold front in the Gulf of Mexico will move slowly SE across the Yucatan Channel and NW Caribbean this evening 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 before diminishing modestly Sun and Mon. ATLANTIC OCEAN... A cold front is about 200 nm offshore of the SE coast of the U.S. and crosses northern Florida into the Gulf of Mexico. Scattered moderate convection is along and within 60 nm SE of a pre-frontal trough extending from 31N76W to 29N78W. Strong SW winds are SE of the front to 29N. Deep layered low pressure lingering across the central Atlantic supports a weakening surface trough from 29N54W to the northern Leeward Islands. Widely scattered clusters of moderate convection are across the central Atlantic east of the trough from 22N51W northeastward to beyond 31N35W. 1026 mb surface high pressure is centered over the eastern Atlantic near 31N27W and is producing moderate to fresh tradewinds across the Tropical Atlantic south of 23N. The cold front moving offshore of NE Florida will move slowly SE, reaching from near Bermuda through the central Bahamas to central Cuba Fri afternoon. Expect fresh to strong southwesterly winds to continue ahead of the front N of 29N through Fri. The front will gradually weaken and become E to W aligned along 24N Sun. High pressure will prevail north of the front through the weekend. $$ Stripling