Monsoon Trough/ITCZ

The monsoon trough reaches the Atlantic through the coast of Sierra Leone near 08N13W and continues southwestward to 04N20W. The ITCZ extends from 04N20W to 03N34W, then resumes W of a surface trough located S of 10N along 35W/36W from 00N37W to 00N50W. Scattered moderate convection is noted from 02N to 06N between 05W and 15W, and from 02N to 06N between 30W and 38W.

Gulf Of America

A ridge extends across Florida into the Gulf region. Under the influence of this system, scatterometer data indicate fresh to locally strong E to SE winds from 23N to 27N E of 87W, including the Straits of Florida. Seas are 5 to 7 ft with these winds, occasionally higher in the Straits of Florida. Elsewhere moderate to locally fresh winds and moderate seas prevail except offshore west Florida where seas of 1 to 3 ft are noted. Scattered showers, with embedded thunderstorms, are occurring over parts of the eastern Gulf and western Florida.

For the forecast, high pressure over the region will begin to retreat eastward Sat evening in response to a cold front that will be approaching the Texas coast. The cold front will reach from the southeastern United States to the central Gulf and to the west-central Gulf Sun, then stall from S Florida to the central Gulf and to the west-centrtal Gulf from early next week into the mid-week. Low pressure may track from W to E along the frontal boundary at about mid-week. Strong northeast winds are expected across portions of the northern and western Gulf behind the front along with rough seas. Moderate to fresh east to southeast winds over the Gulf, with the exception of NE part, will diminish on Sat, but continue at fresh speeds in the Straits of Florida through late Sat night.

Caribbean Sea

The pressure gradient between a ridge N of the area and the Colombian low is supporting fresh to strong NE to E winds offshore Colombia, south of Hispaniola, and also in the Windward Passage. Seas within these wind speeds are 8 to 9 ft offshore Colombia, based on altimeter data, and 6 to 8 ft elsewhere. Moderate to fresh NE to E winds and moderate seas prevail over the remainder of the basin. A diffluent pattern aloft is helping to induce scattered showers and thunderstorms over the NW Caribbean, including parts of Cuba, the Cayman Islands and Jamaica.

For the forecast, the pressure gradient between high pressure centered near Bermuda and low pressure near Colombia will continue to support pulsing strong winds and rough seas offshore Colombia, Cuba, Hispaniola, and through the Windward Passage into Sat. The high pressure will weaken some as it slides eastward this weekend allowing for the pressure gradient to slacken. This will lead to diminishing winds and subsiding seas. An inverted trough will develop from Hispaniola northward into the open Atlantic Mon through Tue and drift westward toward the Bahamas. The pressure gradient between it and central Atlantic high pressure will maintain fresh trade winds across the eastern Caribbean, with gentle to moderate winds elsewhere.

Atlantic Ocean

High pressure of 1032 mb located N of the area near 34N65W extends a ridge across most of the Atlantic forecast waters producing a pretty tight pressure gradient N of 20N and W of 55W. As a result, scatterometer data provide observations of fresh to strong NE to E winds across the weaters N of the Greater Antilles, including the southern and central Bahamas and the Windward Passage. Seas in this area are up to 11 ft based on altimeter data. Over the far E Atlantic, a surface trough extends from a 1014 mb low pressure situated near 26N25W to 20N31W. These features are associated with an upper-level low which generating scattered showers and isolated thunderstorms, more concentrated in the vicinity of 22N21W. Moderate to fresh NE to E winds are seen between the low center and a ridge that extends southward across the Madeira and Canary Islands. Seas are 5 to 7 ft with these winds. Elsewhere, moderate or weaker winds and moderate seas are present.

For the forecast west of 55W, the pressure gradient between high pressure located well north of the area and relatively lower pressure in the subtropics and tropics is allowing for generally strong northeast to east winds along with rough seas over much of the waters S of 26N. These conditions will gradually diminish through the weekend as the high weakens while shifting eastward. An inverted surface trough is forecast to develop from Hispaniola northward into the open Atlantic by Sun night allowing for winds to weaken. The trough will track in a general northwestward direction into mid-week. A cold front is expected to emerge off the southeastern United States coast early on Mon, then slowly move southeastward reaching from near 31N70W to South Florida by Tue morning and stall into mid-week. Low pressure may then develop along the trough at about mid-week as it merges with the frontal boundary and while high pressure builds southward N of the frontal boundary. The resulting tight pressure gradient will bring strong to near gale-force northeast winds along with seas building to a rough state behind this front starting early next week. Mariners are advised to keep up with the latest forecast, especially beyond Mon night.

Posted 0 minutes ago by NHC Forecaster Gr