Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic near 11.5N15.5W and extends to near 02.5N26W. The ITCZ continues from 02.5N26W to the coast of Brazil near 01.5S46W. Numerous moderate to strong convection is noted S of the monsoon trough to 00.5S between 06W and 20W, extending to the coasts of Sierra Leone, Liberia and Cote d'Ivoire. Scattered moderate isolated strong convection is about the ITCZ from 03.5S to 03N between 20W and 47W.

Gulf Of America

Ridging extends from the middle Atlantic coast of the U.S. South and southwestward over the Gulf of America, supporting moderate to fresh E to SE winds over much of the Gulf S of 27N, with moderate or weaker SE to SSE winds elsewhere. Recent satellite scatterometer winds showed easterly winds around 20 kt near and offshore of the Florida Keys and entering the Straits of Florida. These winds are likely amplifying waves within the Florida Current. Otherwise, seas are generally 3 to 6 ft, except 2 to 3 ft across NE portions. Overnight coastal convection across the NE and N central portions has shifted inland this morning.

For the forecast, a ridge extending southward into the eastern Gulf will dominate the basin into the upcoming weekend, supporting mainly gentle to moderate E to SE winds and moderate seas. The southern and western Gulf will experience moderate to fresh E to SE winds during this time, pulsing locally to strong off the NW Yucatan Peninsula each tonight and Fri night as a diurnal trough develops.

Caribbean Sea

Moderate to locally fresh NE winds continue through the Windward Passage, and become moderate to locally fresh easterly winds across the NW portions of the basin. Seas there are 3 to 5 ft except less than 3 ft in the immediate lee of Cuba. Elsewhere, a surface trough across the Atlantic extending from 31N58W to near the entrance to the Mona Passage is leading to reduced trade wind flow across the remainder of the basin. Recent satellite scatterometer winds showed gentle to moderate NE to E winds across most of the rest of the Caribbean, except for fresh winds within 90 nm of the northern coast of Colombia. Seas across these waters are 2 to 4 ft except 5 to possibly 6 ft off the coast of Colombia. A deep layered trough extending from the central Atlantic SW to offshore of Colombia and eastern Panama is supporting scattered moderate isolated strong convection over the Windward Islands and within 90 nm of the South American coasts between 60W and 65.5W.

For the forecast, high pressure will persist along the eastern seaboard of the U.S. While the Atlantic surface trough drifts westward and weakens through the weekend. This pattern will support pulsing fresh NE winds in the Windward Passage, south of Cuba, and offshore Colombia at night into the weekend. Moderate or weaker winds and slight to moderate seas will prevail elsewhere into early next week.

Atlantic Ocean

A surface trough extends from 31N58W to near the entrance to the Mona Passage, supported by a deep layered upper trough directly above it. Meanwhile, a ridge extends from a 1028 mb high centered north of the area, across Virginia. The pressure gradient between these features is supporting fresh to locally strong NE winds occurring from the waters N of 27N60W through the Bahamas and into the Straits of Florida. Rough seas of 6 to 9 prevail in this region from 21N northward. East of the trough, a broad ridge prevails across the Atlantic, centered on a 1030 mb high near 37N40W. Moderate to fresh trade winds are occurring across the waters S of 30N between 25W and 60W. Seas there are 6 to 9 ft. Recent satellite scatterometer winds showed fresh to locally strong SE to E winds occurring between the surface trough and 54W, from 22N to 30N. A relatively broad zone of scattered moderate convection where deep layer lift and moisture are occurring due to the deep layered trough, extends from 15N to 30N between 50W and 60W.

For the forecast west of 55W, the aforementioned troughs will remain relatively stationary through Fri, causing the higher winds and seas to continue. Winds should should diminish by the weekend as the surface trough drifts slowly westward and weakens, allowing the pressure gradient to relax. Looking ahead, a cold front may move southward, between Florida and 65W, late Sunday into Monday followed by moderate to fresh N to NE winds.

Posted 3 hours ago by NHC Forecaster Stripling