Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Guinea-Bissau near 12N16W and continues southwestward to 03N27W. The ITCZ extends from 03N27W to 01N50W. Scattered moderate convection is observed south of 08N and east of 23W.

Gulf Of America

High pressure dominates the Gulf of America, maintaining generally dry conditions. High clouds are seen in the western and northern Gulf waters associated with storms over Mexico and the southern United States. The moderate pressure gradient result in fresh to locally strong easterly trade winds across the southern Gulf waters. This was confirmed by a recent scatterometer satellite pass. Seas in these waters are 3-6 ft. Moderate to fresh E-SE winds and seas of 4-7 ft are noted in the NW and SE Gulf, including the Florida Straits. Moderate or weaker winds and slight to moderate seas prevail elsewhere.

For the forecast, high pressure will be main feature controlling the weather pattern across the Gulf through late Fri. Its associated pressure gradient will maintain moderate to fresh east to southeast winds over the basin through Sat morning. East winds will pulse to strong speeds north of the Yucatan peninsula and over the Bay of Campeche nightly through Fri in association with a diurnal trough. Moderate to fresh east winds and moderate seas are expected over the Straits of Florida through Thu night. Elsewhere, winds will begin to diminish Fri and into the weekend. Looking ahead, a weak cold front may reach the NE Gulf Sat night before shifting east of the basin Sun. High pressure will then build southward across the Gulf leading to mostly fresh easterly winds over most of the forecast zones through early next week.

Caribbean Sea

An upper level trough over the western Atlantic and NW Caribbean Sea results in ample cloudiness and scattered showers over the eastern Caribbean, affecting the nearby islands. Scattered showers and isolated thunderstorms are also evident in the SW Caribbean, affecting Costa Rica, Panama and Colombia. No deep convection is evident in the remainder of the basin.

High pressure north of the islands support fresh to locally strong NE-E winds across the north-central Caribbean, Windward Passage and lee of Cuba. Seas in these waters are 4-7 ft. Elsewhere, moderate or weaker winds and slight to moderate seas are prevalent.

For the forecast, high pressure north of the basin combined with the Colombian Low will support pulsing fresh to strong trades at night over the Windward Passage and south of Cuba through Thu night. At the same time, fresh to strong northeast winds are expected south of the Dominican Republic, mainly near Cabo Beata. Elsewhere, rather quiet conditions are expected over the forecast waters through the weekend.

Atlantic Ocean

A stationary front enters the basin near 31N49W and continues southwestward to 27N58W, where it becomes a dissipating stationary front to 20N67W. A surface trough stretches from 30N48W to a 1014 mb low pres near 23N54W and then continues to the Leeward Islands. Scattered showers and isolated thunderstorms are noted north of 22N and between 48W and 54W. Ample cloudiness is also noted from the Leeward Islands and eastern Greater Antilles to the north- central Atlantic due to the upper level trough over the SW North Atlantic. Moderate to locally fresh NE-E winds and moderate seas are prevalent to the west of the boundaries described. A recent scatterometer satellite pass captured strong winds in association with the strongest convection.

A large and strong extratropical cyclone centered north of Madeira Island supports fresh to strong westerly winds north of 28N and east of 29W. Seas in these waters are 10-15 ft. Fresh to locally strong N winds from 14N to 23N and east of 25W, along with seas of 7-10 ft. The rest of the basin is under the influence of broad subtropical ridge, sustaining moderate to locally fresh easterly winds and moderate seas east of 55W. Elsewhere, moderate or weaker winds and moderate seas prevail.

For the forecast west of 55W, high pressure west of the aforementioned front and low pres will remain about stationary through Fri, then begin to shift eastward into the weekend. The pressure gradient between the low and high pressure to its NW will induce fresh northeast winds north of 25N and east of 65W from Fri morning into the weekend. The low is forecast to slowly lift north- northeastward through Fri night, then weaken into a broad trough on Sat. Looking ahead, a weak cold front will emerge off the northeast Florida coast late Sat night into Sun.

Posted 0 minutes ago by NHC Forecaster Delgado