144 AXNT20 KNHC 181748 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1248 PM EST Wed Dec 18 2019 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 1720 UTC. ...SPECIAL FEATURES... A cold front continues to press eastward across the eastern Gulf of Mexico. This is enhancing gale force winds in the SW Gulf, mostly S of 21N and W of 91W. Seas will range between 14-20 ft in N to NE swell. Expect gale force winds to continue through this evening. Gale force winds are also noted behind the cold front near the Yucatan Channel, S of 24N and W of 84W. These gale force winds are expected to continue moving into the Yucatan Channel and end by this evening. Elsewhere behind the front, strong winds will continue through tonight with frequent gusts to gale force, S of 30N and W of 81W. Seas will range between 9-16 ft in this area. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for further details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Sierra Leone near 07N12W to 05N18W. The ITCZ continues from that point west to 01N30W to NE Brazil near 01S46W. Scattered moderate convection is seen within 150 nm on either side of the ITCZ between 19W-38W. Scattered showers and thunderstorms are seen near the coast of Sierra Leone. GULF OF MEXICO... See the section above for details on the Gale Warning in the Gulf of Mexico. As of 18/1500 UTC, the cold front extends off the southwest Florida coast near 26N82W southwestward to the northern Yucatan near 21N87W. Scattered thunderstorms are within 70 nm of the front and currently entering the Yucatan Passage. High pressure is filling in behind the front and is covering most of the Gulf. The latest scatterometer data depicts northerly gale force winds behind the front near the Yucatan Passage, S of 23N between 85W- 87W. Strong winds cover the eastern half of the Gulf in addition to the SW Gulf with moderate northerly winds off the SE Texas coast. The strong cold front will move southeast of the area later today. Northerly gale-force winds and large seas behind the front in the SW Gulf will persist through the early evening. The wind speeds and the sea heights will diminish in the central and western sections of the Gulf on Thursday and Thursday night. Strong NE to E winds will continue in the Straits of Florida after the frontal passage from Thursday through Friday night. A low pressure center is expected to develop in the eastern Gulf on Friday night and move across northern Florida during the weekend. Gale-force winds are possible in the eastern Gulf with the low pressure center. Strong frontal northerlies across the Gulf of Mexico on Tuesday- Wednesday will result in heavy rainfall amounts between the Mexican States of Veracruz and Tabasco/Campeche. In this area, expect maxima of 4-6 inches on Tuesday. On Wednesday and Thursday, expect additional rainfall amounts of 1-3 inches. CARIBBEAN SEA... As of 18/1500 UTC, a pre-frontal trough is in the NW Caribbean ahead of the incoming strong cold front, analyzed from 16N88W to 23N82W. Scattered moderate convection is seen along this trough and ahead of the cold front from 16N-23N between 82W-88W. Scattered thunderstorms are also seen off the SE Cuban coast between 76W- 79W. The 1007 mb Colombian low has meandered into the SW Caribbean near 10N77W. Scattered showers with isolated thunderstorms are noted throughout this area, S of 13N between 76W-84W. Upper level ridging extends across the eastern Caribbean, inhibiting deep convection. Low- topped showers can be seen moving across the the area. The latest scatterometer data depicts strong trades north of Colombia with fresh to strong winds in the eastern and central Caribbean. Light winds are east of the pre- frontal trough, with moderate to fresh winds behind the trough. High pressure north of the region will maintain fresh to strong trade winds and building seas from the tropical north Atlantic Ocean westward to the south central Caribbean Sea through Saturday. A strong cold front will move into the Yucatan Channel this afternoon. The front will stall and weaken from central Cuba to Honduras by Thursday night. Fresh to strong northerly winds will accompany the front in the NW Caribbean Sea. The strong frontal northerlies will bring heavy rainfall across northwest Honduras to Puerto Barrios in central Guatemala. The heaviest rainfall will occur on Wednesday to Thursday with maxima of 6-8 inches. Due to strong topographical forcing, localized maxima is expected to be between 10-12 inches. ATLANTIC OCEAN... As of 18/1500 UTC, a cold front continues pressing south and east in the western Atlantic, from 31N76W to central Florida near 27N80W. A pre-frontal trough is analyzed from 25N79W to 30N75W. Scattered showers with isolated thunderstorms are seen within 100 nm of the front. Another cold front enters the central Atlantic near 31N27W and stretches westward to 26N42W. A pre-frontal trough is also analyzed ahead of this front from 25N35W to 30N22W. Showers are seen within 90 nm of these features. High pressure dominates the rest of the basin anchored by a 1025 mb high near 27N44W. The latest scatterometer data depicts strong northerly winds behind the cold front in the western Atlantic, with moderate to fresh southerly winds ahead of the front. The strong cold front will reach from 31N69W to eastern Cuba tonight and from 31N64W to eastern Cuba on Thursday morning. By Thursday night, the front will stretch from 26N65W across the Bahamas to the Windward Passage. Strong northerly winds and building seas are expected across much of the forecast waters following the frontal passage. The front will stall gradually, and weaken through Friday night. It is possible that fresh to strong easterly winds may develop to the east of Florida during the upcoming weekend. A low pressure center is forecast to develop in the eastern Gulf of Mexico and move across northern Florida. $$ AKR