Special Features

East Atlantic Gale Warning: Meteo-France has issued a Gale Warning along with very rough seas for their AGADIR Marine Zone, through 22/0000 UTC. Please see the latest HIGH SEAS FORECAST and WARNING issued by Meteo-France at website: https://wwmiws.wmo.int for more information.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic through the coast of Guinea near 10N14W, and continues southwestward to 03N20W, where it transitions to the ITCZ to 01N30W and to just south of the Equator near 01S45W. Numerous moderate to isolated strong convection is seen from the Equator to 07N between 10W and 17W, and within 180 nm south of the trough and ITCZ between 17W and 24W. Scattered moderate is within 60 nm north of the ITCZ between 20W and 24W, and within 30 nm south of the ITCZ between 34W and 37W.

The eastern extension off the East Pacific monsoon trough protrudes eastward into the southwestern part of the Caribbean Sea. Scattered showers and isolated thunderstorms are south of 11N west 78W to along and just offshore the coasts of northern Panama and southern Costa Rica.

Gulf Of America

High pressure ridging extends from a 1025 mb high center that is offshore the South Carolina to across the far northern Gulf. A stationary frontal boundary is just inland the Texas. Increasing scattered showers and thunderstorms are noted along the Texas coast, reaching northeast to southwestern Louisiana. This activity reaches offshore for about 60 nm. Latest ASCAT satellite data passes and buoy data show fresh to strong easterly winds in the Straits of Florida. Latest altimeter satellite data passes indicate seas of 6 to 8 ft in the Straits of Florida. Moderate to locally fresh east to southeast winds, with seas at 4 to 6 ft prevail for the rest of the Gulf.

For the forecast, a tight pressure gradient between high pressure centered offshore the southeastern United States and relatively lower pressure that is in the SW and western Gulf sections will support fresh to strong southeast winds across the southeastern Gulf today, along with moderate to rough seas. Conditions will start to improve Tue as the area of high pressure moves further from the area and the pressure gradient loosens. One exception is off the northwest Yucatan Peninsula where pulses of strong winds are expected as a diurnal trough moves into the waters.

Caribbean Sea

The combination between a 1025 mb high center offshore the southeastern U.S. And relatively lower pressure in South America is supporting fresh to strong trades across most of the Caribbean Sea as noted in the latest scatterometer satellite data passes. Latest altimeter satellite data passes indicated seas of 6 to 9 ft. Mostly moderate northeast to east winds and seas of 4 to 6 ft prevail elsewhere in the Caribbean. Refer to the Monsoon Trough/ITCZ section for convection in the SW Caribbean.

For the forecast, high pressure north of the basin will support fresh to strong northeast winds across the central and western Caribbean through tonight. The high will then shift eastward which will loosen the pressure gradient and diminish winds into late week. Large northerly swell impacting the Mona and Anegada passages will gradually subside early this week. Gentle to moderate winds and slight to moderate seas will then prevail through the end of the week.

Atlantic Ocean

Please see the Special Features section above for information on gale-force winds in the far eastern Atlantic.

A surface trough is analyzed from near 30N58W southward to 20N59W and to just east of Saint Vincent and the Grenadines. Water vapor imagery shows a large and rather elongated low over the the trough covering the area from 22N to 29N between 55W and 64W, and while a prominent upper jet stream branch stretches from the southwestern Caribbean Sea northeastward to the northeastern Caribbean to 22N56W, and well to the east-southeast from there. Ample atmospheric lift and plently of available instability is sustaining a large area of moderate rain along with embedded scattered showers and thunderstorms from 20N to 29N between 40W and 57W. Refer to the Monsoon Trough/ITCZ section for additional convection in the Atlantic Basin.

The gradient between high pressure over the western Atlantic related to a 1025 mb high center off the southeastern U.S. Near 32N77W is supporting a zone of fresh to strong north to northeast winds north of about 19N between 63W-73W. Seas with these winds are in the range of 8 to 11 ft. To the east of the surface trough, latest scatterometer satellite data passes reveal fresh to strong southeast to south winds from 18N to 24N between 54W-57W. Seas are 5 to 8 ft with these winds. Elsewhere to west of the trough south of 26N and between 73W-80W, moderate to fresh northeast to east winds are present, with seas of 4 to 6 ft east of the Bahamas, and 3 ft or less in the vicinity of the Bahamas. Fresh to occasionally strong east winds are west of 80W, including the Straits of Florida. Seas there are generally 6 to 9 ft. Mostly general anticyclonic winds are north of 26N west of the trough, with seas of 3 to 5 ft in long-period east swell. E of 54W, gentle to moderate trades and seas of 3 to 5 ft are present there, except in the far eastern Atlantic north of 20N and east 35W, where fresh to strong northeast winds and seas of 8 to 10 ft are occurring due to the pressure gradient between the Azores high and low pressure over Africa.

For the forecast west of 55W, the pressure gradient between a surface trough and weak low center along 60W and high pressure centered just W of Bermuda will support fresh to strong northeast winds and rough seas today over Atlantic waters east of 70W, as well as south of 25W, including the Bahamas and Greater Antilles. Both the trough and the high pressure will weaken Tue, weakening the pressure gradient and leading to improving conditions through mid-week.

Posted 29 minutes ago by NHC Forecaster Aguirre