000 AXNT20 KNHC 192359 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Tue May 19 2020 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 2345 UTC. ...TROPICAL WAVES... A tropical wave entered the far eastern Caribbean. Its axis is roughly along 62W from 05N to 18N. It is moving westward at 15- 20 kt. The wave marks the leading edge of a large of moisture as noted in the GOES-16 imagery and as indicated by the latest TPW animation. This moisture consists of scattered showers and isolated thunderstorms from 08N to 14N between 51W-59W. This activity. some possibly with strong gusty winds, is forecast to spread over portions of the Lesser Antilles late tonight and Wed. No tropical cyclone development is expected from this system through at least the next several days. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through Guinea near 10N14W and continues to 06N18W, where latest scatterometer data indicates it transitions to the ITCZ and continues to 04N30W to 04N40W and to 04N49W. Scattered moderate convection is seen within 60 nm north of the ITCZ between 24W-34W and also within 30 nm of the ITCZ between 37W-39W. GULF OF MEXICO... As of 21 UTC, a rather weak cold front extends from northeastern Florida to Cross City, Florida and to the eastern Gulf near 27N87W. A weak 1013 mb high center is near 26N89W. The front is devoid of precipitation. A surface trough extends from Stuart, Florida southwestward to near Fort Myers and continues southwestward to 23N86W and to the northern Yucatan Peninsula. This trough is being sustained by a broad upper trough that extends from an upper- level low that is located over the Central Mississippi Valley southward to southern part of the eastern Gulf. Scattered showers and thunderstorms, mainly extending in northeast to southwest oriented lines, are moving eastward across the southeastern Gulf waters along and east of the trough. This activity extends eastward to across most of South Florida. The trough will slowly move southeastward through Wed. Behind the surface trough, moderate to strong subsidence and resultant dry air is suppressing shower and thunderstorm activity from developing over the rest of the Gulf. The scattered shower and thunderstorm activity will continue along and ahead of the surface and upper-level trough through Wed. The weak cold front will continue to weaken through Wed as it slowly moves eastward. Another cold front is forecast to stall along the northern Gulf Coast late Wed through Fri. Elsewhere, smoke from agricultural fires in Mexico may reduce visibility at times in the Bay of Campeche during the next several days. CARIBBEAN SEA... See section above for information on a tropical wave that has entered the Caribbean. Ample deep moisture along with scattered showers and thunderstorms are confined to the northwest part of the sea, where upper-level diffluence is present ahead of the Gulf of Mexico trough. Similar activity is south of 15N and west of 75W. Isolated showers and thunderstorms are elsewhere over the central and western sections of the sea. A moderate pressure gradient between a ridge north of the islands and the Colombian low is producing general fresh to strong trade winds across the central Caribbean, where wave heights are peaking to 9 ft. Gentle to moderate trade winds are elsewhere over the basin. Fresh to strong trades will continue over the central Caribbean through tonight then diminish as broad low pressure dominates the eastern seaboard of the U.S. High pressure will build into the region late Fri through Sat, with the resulting gradient bring a return to fresh to strong trades. The tropical wave over the far eastern Caribbean will move across the rest of the eastern Caribbean through Thu night. Fresh to strong winds will pulse in the Gulf of Honduras Wed night through Fri. Agricultural fires in Central America may reduce visibility at times across the Gulf of Honduras. ATLANTIC OCEAN... A 1022 mb high pressure center is analyzed near 27N42W, with ridging extending westward to near 26N70W. A weak cold front enters the discussion area at 32N34W and continues west-southwestward to near 27N51W. Isolated showers are possible along and near the front. A weak trough extends from just offshore Stuart, Florida southwestward from there to across southwestern Florida and into the southeastern Gulf of Mexico. Scattered showers and thunderstorms, under a favorable upper-level diffluent pattern, are over most of the Bahamas, the Straits of Florida and waters north of the Bahamas to near 30N. Moisture associated with this activity is being advected north-northeastward in strong upper-level winds that are occurring east of a broad upper trough that is over the eastern Gulf of Mexico. Winds and seas, away from the thunderstorms, are generally tranquil. As for the forecast, large northwest from former tropical cyclone Arthur is expected to move into the waters north through northeast of the Bahamas Wed through Fri then subside late Fri through Sat. Otherwise, a weak frontal trough will move across Florida into the far western waters tonight and dissipate on Wed. High pressure will build modestly across the northern waters Fri through Sat night. $$ Aguirre