000 AXNT20 KNHC 192336 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Dec 19 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 2300 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal sections of Sierra Leone near 09N13W to 06N17W. The ITCZ continues from 06N17W to 05N22W to 05N35W to the coast of Brazil near 03N51W. Scattered moderate isolated strong convection is noted from 04N-07N between 28W-39W. Scattered moderate convection can be found from 05N-09N between 39W-46W. GULF OF MEXICO... Currently, Doppler Radar shows a line of thunderstorms extending from SW Louisiana across the NW Gulf to near 24N96W. This convective activity is ahead of a surface trough extending along the coast of Texas into NE Mexico, and will shift eastward tonight. Gusty winds and highest seas will be near thunderstorms. A few of these storms could be strong. A 1030 mb high pressure located over the U.S. Mid-Atlantic states dominates Florida and most of the Gulf waters producing gentle to moderate E-SE winds, with the exception of moderate to fresh SE winds over the NW Gulf, particularly N of 26N and W of 92W based on satellite-derived wind data. A cold front will move across the NW Gulf this evening followed by fresh to locally strong northerly winds. The front will reach from SE Louisiana to near Tampico, Mexico tonight, from the western Florida Panhandle to near Veracruz, Mexico on Sun, reaching the SE Gulf on Sun night. The cold front will exit the basin by Mon. High pressure is expected behind the front. A stronger cold front is forecast to reach the coast of Texas by Wed evening, reaching from SE Louisiana to just S of Brownsville by Wed night. The GFS computer model suggests strong to gale force winds and building seas in the wake of the front on Thu. CARIBBEAN SEA... The most recent scatterometer data provided observations of strong to near gale force winds over the south-central Caribbean. Fresh winds were also noted south of Hispaniola and over the Windward Passage. These winds are the result of a high pressure located north of the area over the U.S. Mid-Atlantic states. These winds will persist tonight and Sun morning as the high pressure remains in place. Then, winds will diminish across the basin later on Sun as high pressure moves northeastward. Shallow moisture embedded in the trade wind flow will move across the region producing isolated to scattered passing showers. This activity is now more concentrated over Jamaica, NE Honduras and eastern Nicaragua. NE winds over the Bahamas, and the Old Bahama Channel are also advecting patches of low level moisture into parts of Cuba. A cold front is forecast to reach the Yucatan Channel and western Cuba on Mon, then gradually weaken over the NW Caribbean through Tue. Another and stronger cold front is expected to move across western Cuba and the NW Caribbean by late Thu. Fresh to strong winds will follow the front. ATLANTIC OCEAN... A cold front extends from 31N50W, across the SE Bahamas into central Cuba. Cold air stratocumulus clouds are noted behind the frontal boundary. Mainly moderate northerly winds are noted in the wake of the front, with an area of fresh winds just N of the SE Bahamas. High pressure is building in over the western Atlantic behind the front. A ridge prevails over the east Atlantic, anchored by a 1025 mb high pressure centered near 30N26W. Fresh trade winds are seen along the southern periphery of the ridge affecting the Cabo Verde Islands and regional waters. The next cold front will move off the Florida coast on Mon. Fresh to strong winds are expected on either side of the front but mainly N of 26N. The front will reach from 31N73W to the Straits of Florida on Mon afternoon, and from near Bermuda to west-central Cuba on Mon night. $$ GR