855 AXNT20 KNHC 241150 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 650 AM EST Sun Nov 24 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 0600 UTC surface analysis and satellite imagery through 1145 UTC. ...SPECIAL FEATURES... The center of Tropical Storm Sebastien, at 24/0900 UTC, is near 36.0N 40.0W. Sebastien is moving NE at 28 kt. The estimated minimum central pressure is 994 mb with maximum sustained wind speeds up to 55 kt and gusts to 65 kt. Scattered moderate convection is seen 400 nm in the northeastern quadrant. An additional increase in speed toward the northeast is expected during the next day. On the forecast track, the center of Sebastien will pass near the western Azores tonight. A slow decrease in the maximum winds is expected during the next couple of days. Sebastien is forecast to become post-tropical tonight and then merge with another weather system over the northeastern Atlantic on Tuesday. The Public Advisories for Sebastien are available via AWIPS/WMO headers MIATCPAT5/WTNT35 KNHC. The Forecast/Advisories for Sebastien are available via the AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC or at www.hurricanes.gov. ...TROPICAL WAVES... An Atlantic Ocean tropical wave has an axis along 44W from 11N southward, moving W at 10-15 kt. Scattered moderate convection is seen along the wave axis from 5N-12N between 41W-46W. An Atlantic Ocean tropical wave has an axis along 62W from 13N southward and is moving W at 10 kt. Scattered showers are seen in the vicinity of the wave axis near the Windward Islands. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Liberia near 06N10W to 05N16W. The ITCZ continues at that point to 03N29W to 05N41W, then west of the tropical wave from 04N46W to 04N51W. Scattered moderate to strong convection is seen along the monsoon trough near the coast of Liberia and Sierra Leone between 09W-13W. A line of showers and thunderstorms are about 100 nm north of the ITCZ from 01N-08N between 16W-30W. Scattered moderate to strong convection is seen along the ITCZ from 03N-08N between 30W-41W. GULF OF MEXICO... A cold front is pushing across the central and western Gulf, entering the waters from FL near 28N82W and stretching SW across the Gulf to the coast of Mexico near 19N96W. Showers with isolated thunderstorms are within the front. A pre-frontal trough near 160 nm SE of the front is producing scattered showers and tstorms N of 26N across the Florida Peninsula to 84W. Surface ridging is building right behind the front in the western Gulf. Scatterometer data depicts gentle SW winds in the eastern Gulf with moderate NW winds behind the front. The cold front will reach from near Florida Bay to just NW of the Yucatan Peninsula this evening, stalling and weakening from the Straits of Florida to near the Yucatan Channel by early Mon. High pressure will build in the wake of the front from W to E, shifting NE of the basin by early Tue. The next cold front is expected to move into the NW Gulf by early Wed, weakening and stalling in the northern Gulf by Wed night. SE return flow around high pressure over the Carolinas will prevail Thu and Thu night. CARIBBEAN SEA... Relatively quiet weather is seen across the basin with upper high centered near the Gulf of Honduras. Scattered showers and tstorms are noted from 13N-15N between 64W-70W. Latest scatterometer depicts fresh to strong winds in the central Caribbean, gentle trades in the southern basin, and moderate to fresh trades across the rest of the basin. Gentle to moderate trades will prevail through this evening, increasing to moderate to fresh outside of the NW Caribbean tonight. Winds will continue to increase to moderate to fresh throughout, except fresh to strong in the S central Caribbean through the early part of the week. Strong to near gale force winds are forecast near the coast of Colombia Tue night into Wed. Fresh to strong trades will spread from the S central portion to the W central by mid-week. ATLANTIC OCEAN... A trough extends south of T.S. Sebastien from 17N55W to a 1013 mb low near 22N51W to 30N42W. Scattered showers and tstorms extend from 19N-28N between 45W-50W. An upper level low near 24N33W is bringing an area of scattered showers from 20N-30N between 17W- 30W. High pressure dominates the rest of the area anchored by a 1019 mb high in the western Atlantic near 28N68W and a 1022 mb high in the eastern Atlantic near 30N27W. High pressure located SE of Bermuda extends a ridge to S Florida. A cold front in the Gulf of Mexico will move across Florida today, reaching from Bermuda to the central Bahamas to the Straits of Florida by early Mon where it will stall and gradually wash out through Tue. Fresh to strong winds are expected on either side of the front mainly N of 28N. The front will stall from 30N65W to 27N75W to western Cuba on Tue while weakening. High pressure will build in the wake of the front. Another cold front is forecast to move across the basin Thu through Thu night. $$ AKR