000 AXNT20 KNHC 271740 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu May 27 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 22W south of 13N. It is moving westward at 15 to 20 kt. Scattered moderate to isolated strong convection noted with 300 nm of either side of the wave from 01N to 06N. Another area of similar convection is noted east of the wave from 02N to 05N between 05W to 16W. Another tropical wave has its axis along 42W south of 12N. It is moving westward at 15 to 20 kt. This wave is located under a more stable upper environment that is marked by subsidence and dry sinking air found behind an upper-level trough. Scattered moderate convection is west of the wave to the coast of Brazil from 03N to 07N. ASCAT data from earlier today notes a surge of fresh NE winds west of the wave. ...MONSOON TROUGH/ITCZ... The monsoon trough remains inland in Africa. The ITCZ is identified between the tropical waves from 05N26W to 04N39W. Scattered moderate convection is within 100 nm north of the ITCZ between 28W to 34W. GULF OF MEXICO... A ridge dominates the Gulf anchored by a 1022 mb surface high pressure center over the western Atlantic. A local 1021 mb high pressure center is south of the Florida Panhandle near 29N84W. High pressure and deep layer dry air apparent in water vapor satellite imagery is keeping mainly fair weather conditions in place. ASCAT data notes gentle to moderate E to SE winds are across the basin. Seas are 1 to 2 ft in the NE Gulf and 3 to 5 ft in the SW Gulf. For the forecast, gentle to moderate east to southeast winds are expected through Sat night as weak high pressure off the NE Florida coast extends westward to SE Texas and gradually weakens. Fresh northeast to east winds will pulse nightly to strong off the Yucatan Peninsula through Sat. A cold front is expected to move across the northern Gulf on Sat night into Sun, then stall across the northern Gulf Sun night. Expect moderate north to northeast winds behind the front. CARIBBEAN SEA... The monsoon trough is analyzed over eastern Panama into the eastern Pacific. Scattered moderate convection associated with the trough is in the SW Caribbean, south of 10N. Debris high level cloudiness from this activity continues to stream eastward over the SW Caribbean. ASCAT data from this morning reveals fresh to strong NE winds over the central and south-central Caribbean, south of 16.5N. Wave heights with these winds are in the 6 to 11 ft range. Gentle to moderate trades are elsewhere across the basin with seas ranging from 3 to 5 ft. As for the forecast: Fresh to strong trades will prevail across the central portions of the Caribbean through early today as high pressure resides in the western Atlantic. Winds will diminish significantly through early next week as the high collapses. Fresh winds are expected in the southern Gulf of Honduras and the Windward Passage tonight. ATLANTIC OCEAN An upper-level low is vividly noted near 27N64W, with a surface trough stretching from 30N63W to 23N65W. A very moist and unstable atmospheric environment around the upper-level low along with upper diffluence is supporting scattered moderate convection within 270 nm east of the surface trough. The GOES-16 geostationary lightning mapper reveals frequent lightning within this convection. Otherwise, high pressure is anchored in the western Atlantic near 31N68W allowing for gentle return flow west of 65W with seas of 3 to 5 ft. Farther east, another area of high pressure is centered near 37N40W allowing for gentle to moderate NE to E winds across the basin. Seas east of 50W range from 6 to 9 ft. For the forecast, light winds will prevail north of 24N through today as a weak trough along 65W interrupts the Atlantic ridge. Moderate to locally fresh winds will continue across the Bahamas and Greater Antilles through this morning. Winds will become gentle to moderate later today through Sun as the Atlantic ridge extends from the east-central Atlantic weakly WSW to Florida. Fri night, moderate to fresh southerly winds will develop off the NE Florida coast ahead of a cold front forecast to emerge off the southeastern CONUS early Sun. A cold front will move across northern Florida on Sun before stalling Sun night. $$ Mora