536 AXNT20 KNHC 220538 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1238 AM EST Fri Nov 22 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 0000 UTC surface analysis and satellite imagery through 0520 UTC. ...SPECIAL FEATURES... Tropical Storm Sebastien is near 24.7N 57.8W at 22/0300 UTC, or about 490 nm NE of the northern Leeward Islands, moving NE at 16 kt. Minimum central pressure is 999 mb. Maximum sustained wind speeds are 50 kt with gusts to 60 kt. Numerous moderate with scattered strong convection is within 120 nm of the center in the NE quadrant and 150 nm NW quad. Scattered moderate with isolated strong convection is elsewhere within 210 nm of the center in the NE, SE and NW quads, and only within 30 nm SW quad. The cold front approaching Sebastien is now only about 80 nm west of Sebastien. Sebastien is forecast to continue moving NE with an increase in forward speed, with little change in strength. 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. ...TROPICAL WAVES... An eastern Atlantic Ocean tropical wave has been added to the map along 32W, moving W around 10 kt. The wave shows up well in TPW imagery and model diagnostics. Numerous moderate with scattered strong convection is seen from 02N-08N between 27W-33W. Another, weaker tropical wave has also been added to the map along 41/42W from 05N-12N, moving W-NW around 5-10 kt. Scattered moderate convection from 10N-15N between 35W-41W may be more due to the upper-level low near 20N41W rather than the tropical wave. An Atlantic Ocean tropical wave is along 52W from 12N southward, moving W at 10-15 kt. Isolated showers are within 120 nm of the wave axis. A Caribbean Sea tropical wave is along 79/80W, from 07N-16N, moving W around 10 kt. Isolated showers and tstorms are within 60 nm of the wave axis from 11N-16N. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Sierra Leone near 07N12W to 07N15. The ITCZ continues from 07N15W to 02N31W, then continues W of a tropical wave from 03N33W to 02N47W. Aside from the convection mentioned above in the Tropical Waves section, isolated moderate convection is seen from 02N-06N between 10W-16W. GULF OF MEXICO... Deep-layered anticyclonic wind flow covers the basin. Scattered showers are over SE Texas, well ahead of a cold front over north- central Texas. The latest ASCAT pass shows moderate to fresh SE winds across the basin. A surface ridge will prevail across the area through today, with fresh SE return flow persisting over the western Gulf. A cold front will move off the Texas coast and into the NW Gulf tonight, cross the northern and central waters this weekend, then weaken and stall over the southern Gulf Sun night. CARIBBEAN SEA... As of 22/0300 UTC, a stationary front extends from the Mona Passage to the north coast of Jamaica to 20N85W. Isolated moderate showers and tstorms are present along and south of the front, north of 14.5N between 64.5W-72W. The latest ASCAT pass shows strong N-NE winds in the Mona and Windward Passages, and south of the Dominican Republic and Cuba. The stationary front will weaken today. Fresh NE winds will prevail across much of the western Caribbean through today, with the strongest winds expected through the Windward and Mona passages as high pressure builds behind the front. Easterly trades will freshen across the south-central Caribbean early next week. ATLANTIC OCEAN... A cold front passes through 32N56W to 24N62W to the Mona Passage. The front is only 80 nm west of T.S. Sebastien. Aside from the convection mentioned in the section above associated with Sebastien, scattered moderate convection is along and within 210 nm E of the cold front north of Sebastien to 32N. To the west of the cold front, surface high pressure ridging prevails, thanks to a 1025 mb high centered near the coast of South Carolina. Fresh N to NE winds are throughout the Bahamas region. Strong N winds are from 20N-30N between 63W-70W. Farther east, an upper-level low near 20N41W is inducing scattered showers and isolated tstorms from about 15N-25N between 30W-43W. North of that, fair weather prevails due to a 1023 mb high centered near 32N36W. A cold front extends from 32N12W to the Canary Islands near 28N16W to 26N20W to 26N26W with no significant precipitation noted. The cold front from 32N56W to the Mona Passage will continue moving eastward and steer Sebastien into the central Atlantic. High pressure will build behind the cold front across the northern waters through Sat, then shift eastward Sat night. The next cold front will cross the western Atlantic Sun through Mon. $$ Hagen