Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic through the coast of Guinea-Bissau near 12N16W and continues southwestward to 04N20W, where latest scatterometer data indicates that it transitions to the ITCZ to the Equator at 30W and to below the Equator at 34W reaching to near 01S46.5W. Scattered moderate to isolated strong convection is within 60 nm north of the ITCZ between 21W-26W, and from 01S to 02N between 45W and the coast of Brazil. Scattered moderate convection is within 60 nm north of the ITCZ between 37W-41W.

Gulf Of America

High pressure of 1024 is centered between southeastern U.S. And Bermuda, with a ridge extending west-southwestward to the central Gulf. The gradient between it and lower pressure in the western part of the Gulf and in Texas and Mexico is supporting moderate to fresh return flow over the western Gulf waters and moderate seas. Moderate to locally fresh easterly winds re north and west of the Yucatan peninsula. An overnight altimeter satellite data pass indicated seas of 3 to 4 ft with these winds. Slight higher seas of 3 to 5 ft are over the Bay of Campeche, the SW Gulf and the west-central Gulf. Seas of 4 to 6 ft are over the NW Gulf and over the offshore waters of southwest Louisiana. Elsewhere, moderate or weaker winds and slight to moderate seas prevail.

For the forecast, the moderate to fresh southerly return flow over the western Gulf will continue into early Fri evening. Looking ahead, low pressure that is currently over the High Plains region will send a cold front to the NW Gulf on Sat afternoon, followed by fresh to near gale north to northeast winds expected Sat night through Sun night. Gale conditions are possible offshore Tampico on Sun and offshore Veracruz Sun afternoon and Sun night. Fresh to strong east to southeast winds will pulse along and near the northern portion of the Yucatan Peninsula from the afternoons and into the morning hours in association with the Yucatan Peninsula diurnal trough starting Thu. Mariners are urged to stay up to date with the latest forecasts.

Caribbean Sea

The gradient between Atlantic high pressure and relatively lower pressure in northern South America is sustaining fresh to strong northeast to east winds in the south- central Caribbean and strong to near-force northeast winds offshore Colombia as seen in an overnight scatterometer satellite data pass across that part of the sea. In addition, a ship reported northeast 25 kt winds at location 11N76W around 04Z. Similar winds are in the Gulf of Venezuela. Seas over these waters are 7 to 9 ft. Moderate to fresh trades along with moderate seas are in the north-central Caribbean, including the Windward Passage. Moderate to locally fresh trades and moderate seas are in the eastern part of the sea. Elsewhere, moderate or weaker winds and slight to moderate seas are prevalent. Isolated showers, with the trade wind flow are present in the eastern part of the sea north of 12N and east of 68W. Similar showers are near the coast of Hispaniola and between Cuba and Jamaica.

For the forecast, the gradient in place will maintain little change with the trades through the end of the week, however, the fresh to strong trades in the south-central part of the sea will expand in coverage. Winds may pulse to near gale-force off Colombia at nigh during this time. Fresh northeast winds will pulse in the Windward Passage through Thu. Fresh to strong east to southeast winds will begin to pulse in the Gulf of Honduras Wed evening and continue through Sat night, while trades elsewhere will generally remain moderate to fresh. Large north swell is expected to impact the tropical N Atlantic waters and the Anegada/Mona Passages beginning on Thu and likely subsiding on Sat.

Atlantic Ocean

A cold front extends southwestward from a hurricane-force extratropical low that is well south of Newfoundland, to the tropical Atlantic near 31N51W and continues southwestward to 26N63W, where it becomes a stationary front to the central Bahamas. A broad upper-level trough is over the western Atlantic. Satellite imagery shows scattered to numerous showers and isolated thunderstorms out ahead of the cold front, east-southeast to a line from 31N45W to 25N49W and to 22N60W. Overnight scatterometer satellite data passes reveal moderate to fresh northeast to east winds west of the front to near 76W and from 23N to 28N. To the north, a 1024 mb high center is analyzed near 32N71W. Light to gentle anticyclonic winds are north of 28N between 67W and 76W. Seas are 8 to 12 ft behind the front in long-perid northwest swell, except for higher seas of 10 to 15 ft north of 29N between 55W and 60W. Moderate to fresh southwest winds and mostly moderate seas are ahead of the cold front to 49W and north of 27W.

A trough is analyzed from near 31N32W to 27N44W. No significant convection is presently noted with this feature.

The remainder of the tropical Atlantic is dominated by broad high pressure, with the associated gradient generally allowing for moderate to fresh northeast to east winds southeast of a line roughly from 26N35W to 20N50W and to the northern Leeward Islands. Seas about 5 to 7 ft within this area. Elsewhere, light to gentle winds and moderate seas are present. Saharan dust is noted in the eastern Atlantic east of about 33W. Surface observations from the Cape Verde Islands are reporting dust

For the forecast west of 55W, the aforementioned cold front will become a weakening stationary front from 25N55W to near 23N67W by early this evening, then weaken and dissipate Thu. Fresh to strong southwest winds ahead of the cold front north of 29N will shift north of 31N this morning. Behind the front, large to very large N swell will occur with 12 ft or greater seas sliding east of 55W north of 28N tonight. Seas of 8 to 10 ft will propagate southward reaching to near 20N on Thu, then shifting east of 55W on Fri while subsiding. Light to gentle anticyclonic winds are expected for most of the offshore zones from this evening through Sat night as a high pressure ridge initially builds westward near 27N before it shifts southeastward Sat through Sun night in response to a frontal system that will be moving through the southeastern U.S. A strong cold front with this system is expected to push off the Georgia and NE Florida coasts on Sun, followed by increasing NW winds and building seas.

Posted 0 minutes ago by NHC Forecaster Aguirre