AXNT20 KNHC 212314

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Thu Apr 22 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 2300 UTC.


The monsoon trough passes through the coast of Guinea near 11N15W and continues SW to 03N22W. The ITCZ extends from 03N22W to 01N35W to the coast of Brazil near 00N50W. Scattered moderate and isolated strong convection is from 00N-06N between 10W-30W, from 00N-03N between 30W-36W, and from 00N-03N between 45W-49W.


A cold front extends from Naples, Florida southwestward to the eastern Bay of Campeche near 21N92W. Scattered showers with embedded thunderstorms is ahead of the frontal boundary over the SE Gulf. This convective activity is reaching the northern coast of western Cuba. Another cold front extends from the Florida Big Bend to just south of Brownsville, Texas. Cold air stratocumulus clouds are noted behind the front, particularly W of 90W as seen on visible satellite imagery. Fresh north to northeast winds follow the fronts. Winds and seas could be higher near tstms in the SE Gulf.

The first front will exit the SE Gulf this evening. The second cold front will reach from west-central Florida to the central Gulf by late tonight, then weaken early Thu as it reaches from southwest Florida to near 23N90W. Fresh to strong southerly return flow will develop over the western Gulf Fri, shift to the central Gulf early Sat and diminish late Sat as another cold front enters the far NW Gulf. This front will move across the rest of the Gulf waters through Sun night as it weakens. In its wake, high pressure will shift eastward across the Gulf region through Mon night.


The most recent satellite derived wind data provided observations of fresh to strong trades over the south-central Caribbean, with near-gale force winds within about 90 nm of the coast of Colombia. Moderate to fresh trade winds were noted elsewhere, with the exception of light and variable winds across the Windward Passage, and an area of fresh easterly winds across the Leeward Islands and regional waters, including the Anegada Passage. Seas are in the 6-9 ft range over the south-central Caribbean, 4-6 ft elsewhere over the eastern and central Caribbean, and 3-5 ft over the NW part of the basin. Patches of low level moisture embedded in the trade wind flow are currently reaching Puerto Rico and the US/UK Virgin Islands producing isolated to scattered passing showers.

Fresh to strong trade winds over the central Caribbean will diminish slightly late in the week as high pressure over the central Atlantic shifts eastward, except near the coast of Colombia where these winds will persist through the week. Seas are also forecast to subside from 7-10 ft tonight to 5-7 ft by Fri night near the coast of Colombia.


W of 65W, a cold front extends from 31N70W to South Florida into the Gulf of Mexico. Some shower activity is associated with the front, forecast to weaken as it reaches from near 31N67W to central Cuba by early Thu. At the same time, a second cold front that will move off the southeastern U.S. coast this evening will reach from near 31N70W to South Florida on Thu. The second front will merge with the remnants of the first front Thu afternoon, reaching from 31N65W to the Straits of Florida by Thu evening. The merging front will weaken as it moves across the waters NE of the Bahamas through late Fri. Fresh to strong NW winds are expected in the wake of the second front tonight into early Thu morning with seas of 6-7 ft. High pressure will follow the merging front and will dominate the waters W of 65W Thu night through Sat.

On Sat night, a stronger cold front is expected to approach the southeastern U.S. coast and move across the waters NE of the Bahamas through Mon night while weakening. Fresh to strong southerly winds will develop over the waters N of 27N and W of 70W Sat and Sat night. The forecast currently calls for southerly winds of 20-30 kt, and building seas in the 8-9 ft range. These marine conditions will shift eastward, covering mainly the area N of 27N between 65W and 75W through Sun night. Scattered showers and thunderstorms are possible ahead of this front.

Elsewhere E of 65W, a 1023 mb high is centered near 26N40W with the associated ridge covering the remainder of the Atlantic forecast waters. A storm force 992 mb low pressure is located north of the area. The attendant cold front enters the forecast region near 31N40W and extends along 29N50W to 29N58W. Seas generated by this storm are currently reaching the northern forecast waters E of 55W, building seas to 8-12 ft in NW swell.

$$ GR