063 AXNT20 KNHC 201734 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue Apr 20 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 1200 UTC surface analysis and satellite imagery through 1710 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 08N13W, 03N20W, to 01N25W. The ITCZ continues from 01N25W, to the Equator along 35W, and continuing along the Equator at 45W, to 04N50W. Precipitation: widely scattered moderate to isolated strong in clusters is from 10N southward from 56W eastward. GULF OF MEXICO... A cold front passes through Lake Okeechobee in Florida, to 25N85W in the Gulf of Mexico. The front becomes stationary at 25N85W, and it continues to a 1012 mb low pressure center that is near 21N95W. The stationary front continues from the 1012 mb low pressure center, to 19N94W, and to 18N96W. A surface trough runs north-to-south, in the Yucatan Peninsula. Precipitation: scattered to numerous strong is within 180 nm to the south of the frontal boundary between 81W and 87W. Widely scattered moderate to isolated strong is from 25N southward from 87W eastward. Isolated moderate is elsewhere from 28N southward from 88W eastward. It is possible that strong gusty winds and rough seas may be in some of the areas of the comparatively heavier and more intense precipitation. A cold front extends from Fort Myers, Florida, to 24N90W, where it transitions to a stationary front to the Bay of Campeche. The cold front will be nudged southward, to the far southeastern Gulf of Mexico on Wednesday, and to the lower Straits of Florida on Wednesday night. High pressure in its wake, will shift eastward through Saturday night, as a cold front reaches eastern Texas. Fresh to strong southerly winds will develop in the NW and in the central Gulf of Mexico, from late Friday through Saturdat. Scattered rainshowers and thunderstorms will be focused along and near the cold front today and tonight. Some of this activity may produce strong gusty winds and rough seas. CARIBBEAN SEA... Water vapor imagery and the GFS model for 250 mb show an anticyclonic circulation center that is in the SE coastal sections of Nicaragua. Upper level anticyclonic wind flow covers the Caribbean Sea from 70W westward. Upper level cyclonic wind flow covers the Caribbean Sea from 70W eastward, with an Atlantic Ocean trough. The GFS model for 700 mb shows: Broad cyclonic wind flow covers the SW corner of the Caribbean Sea, from 15N southward from 72W westward. Precipitation: scattered to numerous strong is in SE Nicaragua. Widely scattered moderate to isolated strong is in a line from central Panama toward SE Nicaragua. The monsoon trough is along 11N73W in northern Colombia, through the border of Colombia and Panama, beyond 07N80W and 07N86W, into the eastern Pacific Ocean. Precipitation: scattered to numerous strong is in SE Nicaragua. Widely scattered moderate to isolated strong is in a line from central Panama toward SE Nicaragua. Broken to overcast low level clouds, and isolated moderate rainshowers, cover the rest of the Caribbean Sea. The clouds and isolated moderate precipitation are moving with the surface-to-low level wind flow. Fresh to strong trade winds in the central Caribbean Sea will diminish by late in the week, as high pressure in the central Atlantic Ocean shifts eastward, except near the coast of Colombia where these winds will persist through the week. ATLANTIC OCEAN... A first cold front passes through 32N68W, to Lake Okeechobee in Florida. A second cold front passes through 32N73W to 30N80W, about 130 nm to 180 nm to the NW of the first cold front. Precipitation: widely scattered to scattered moderate, and isolated to widely scattered strong, are to the northwest of the line that passes through 32N50W, to 26N60W, and to 23N80W. It is possible that strong gusty winds and rough seas may be in some of the areas of the comparatively heavier and more intense precipitation. A surface ridge extends from a 1023 mb high pressure center that is near 33N21W, to a second 1023 mb high pressure center that is near 28N33W, to a 1024 mb high pressure center that is near 27N43W, 24N69W, across the Bahamas and Cuba, to 20N82W in the NW corner of the Caribbean Sea. Surface anticyclonic wind flow covers the Atlantic Ocean, away from the 32N68W-to-Lake Okeechobee in Florida cold front, eastward and southeastward. The current weak cold front, that extends from 31N70W to West Palm Beach, Florida will stall E of 75W near 30N tonight, while W of 75W it will continue slowly southward. By early Wednesday, the stationary front will have move northward as a warm front, while the cold front will extend from NE of the Bahamas to the Florida Keys, and from near 31N69W to the central Bahamas and to west central Cuba by late Wednesday night, as another cold front moves into the NW waters. By late Thursday, both fronts will be weakening NE of the Bahamas, as high pressure builds into the area. The high pressure will shift eastward through Saturday night, as a stronger cold front approaches the southeastern U.S.A. coast. The stronger cold front will be preceded by fresh to strong southerly winds in the far NW waters, along with possible scattered showers and thunderstorms. $$ mt/ja