000 AXNT20 KNHC 112130 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Apr 12 2021 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 2100 UTC. ...SPECIAL FEATURES... Windward Islands Ashfall Advisory: La Soufriere volcano on the island of Saint Vincent near 13.3N 61.2W is undergoing frequent eruptions. Satellite imagery shows the volcanic ash plume spreading well to the east and northeast of St. Vincent, roughly in an area from 10N-18N between 40W-62W, which includes Barbados. Violent volcanic eruptions may occur suddenly without warning. Volcanic ash may be reaching the ocean surface east northeast of St. Vincent. Mariners should exercise caution, and report volcanic ash or floating debris to the National Weather Service by calling 305-229-4424. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends southward from the coast of Guinea-Bissau near 12N16W to 04N22W, where it transitions to the ITCZ to 01N30W to 00N40W. Scattered moderate convection is within 180 nm south of the ITCZ between 20W-27W. GULF OF MEXICO... Low pressure of 1009 mb has formed in the NE Gulf just S of the Florida Panhandle. A cold front extends SW from this low to just north of Tampico, Mexico. A surface trough resides in the western Gulf from 25N92W to 21N97W. Another pre-frontal trough, accompanied by strong to severe thundertorms, strethes from near Fort Myers, Florida to 27N88W. Between the pre-frontal trough and cold front, numerous thundertorms, some strong, are ongoing. Very gusty wind to 45 kt and frequent lightning are hazards through much of the eastern Gulf of Mexico. Ahead of the through, fresh SW winds prevail. North of the cold front, moderate to fresh mainly N winds are occuring, with mainly gentle winds elsewhere in the Gulf. Seas average 3 to 6 ft. The cold front will move east, then stall out from central Florida to the Bay of Campeche Mon, and dissipate by Mon night. An upper- level trough will help generate scattered showers and thunderstorms over the southeastern Gulf waters through this evening. Some of this activity may contain frequent lightning and strong gusty winds. CARIBBEAN SEA... See the Special Features section above for details on an Ashfall Advisory issued for ongoing volcanic eruptions on St. Vincent. The latest surface analysisdep icts a rather weak pressure gradient across the basin. Fresh trades prevail over most of the basin, while fresh to strong east-southeast winds in the Gulf of Honduras as well as the Yucatan Channel. Mainly fair weather conditions are in place across the basin. Wave heights are in the 3-6 ft range, except for slightly higher wave heights of 5-7 ft in the central Caribbean area and within the Gulf of Honduras. For the forecast, fresh southeast winds will continue over the northwestern Caribbean through the period, while fresh to strong east to southeast winds continue in the Gulf of Honduras. Winds will pulse to strong speeds over a small area near the coast of Colombia during the afternoons and at night through Wed. Elsewhere, generally moderate to fresh east winds will change little through Thu night. ATLANTIC OCEAN... See the Special Features section above for details on an Ashfall Advisory issued for ongoing volcanic eruptions on St. Vincent. A surface trough extends from 31N75W to near West Palm Beach, Florida. Along and to the northwest of this trough, numerous strong thunderstorms are occurring. These thunderstorms will bring a threat of frequent lightning and wind gusts to 50 kts for arease W of 72W and N of 24N, including the NW Bahamas and off the east coast of Florida. Ahead of the trough, N of 23N and E of 65W, fresh SW winds are occurring. For the forecast, fresh to locally strong southerly winds east of Florida will shift eastward through Mon ahead of a cold front that will move off the southeastern U.S. coast tonight. The front will reach from near 31N75W to east-central Florida early Mon, from near 31N70W to the central Bahamas and to east-central Cuba Mon evening and the southeast waters by late Tue. The front will move east of the forecast waters on Wed as weak high pressure builds in behind it. Another cold front is expected to cross the northwest and north- central waters on Tue. Fresh to strong southwest winds are expected to precede this front. Scattered to numerous showers and thunderstorms, some strong to severe, are expected to push off the Florida coast through this evening. Farther east, a large area of fresh to strong west winds associated with a low pressure system north of our discussion area continues to affect waters north of 27N between 27W-45W. Seas are 11-17 ft in this area. Northerly swell from this system, with seas in excess of 8 ft, is affecting most of the central Atlantic north of 21N between 26W-60W. South of the low, weak surface trough is analyzed from 28N37W to 18N60W. Another trough is noted from 28N30W to 17N50W. To the E of 45W, scattered moderate convection exists along both of these troughs. High pressure ridging and gentle anticyclonic flow dominates the waters both west and east of the troughs. $$ KONARIK