Hurricanes

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Guinea-Bissau near 12N17W and continues southwestward to 07N20W. The ITCZ extends from 07N20W to 02S33W and to 03N50W. Widely scattered showers are present south of 04N and east of 33W.

Gulf Of Mexico

Divergence aloft and tropical moisture support a few showers over the NW Gulf while generally dry conditions are present in the rest of the basin. A weak high pressure over the NW Gulf sustain moderate to fresh E-SE winds and seas of 3-6 ft south of 25N and west of 88W. Light to gentle winds and slight seas are found in the rest of the Gulf.

For the forecast, the pressure gradient between weak high pressure over Florida and the eastern Gulf, and relatively lower pressures over the rest of the Gulf and in Mexico will support mostly fresh southeast winds over the western and central Gulf through the forecast period. Fresh to strong winds will pulse at night for the next few days near the northern and western Yucatan Peninsula due to local effects induced by a thermal trough.

Caribbean Sea

A sharp upper trough reaches north of the Caribbean from over Bermuda through the northern Bahamas. This is supporting a surface trough over Haiti, which in turn is disrupting the normal subtropical ridge that is resident to the north of the Caribbean. This is resulting in relatively light winds and modest seas across western half of the basin. Moderate to fresh SE winds and 3-6 ft seas are noted elsewhere over the eastern Caribbean. Divergent flow aloft associated with the upper trough is also supporting scattered showers and thunderstorms across the Windward Passage, eastern Cuba, and the higher terrain of Haiti and the Dominican Republic. Refer to local weather advisories for information regarding any heavy rainfall or related flooding.

For the forecast, high pressure centered N of the region is supporting moderate to fresh trade winds over the central and eastern Caribbean. These winds will gradually subside into the weekend as the pressure gradient relaxes. Moderate to fresh northeast winds are expected in the lee of Cuba, northwestern Caribbean, and just in the Windward Passage into Fri night and in the Windward Passage Sat night and Sun night. Gentle to moderate trade winds are expected over the area through the forecast period, except for mostly fresh winds in the south-central Caribbean. The interaction between a trough along 80W/81W south of 20N with the base of a western Atlantic upper-level trough that extends into the western Caribbean has resulted in the development of scattered showers and thunderstorms from the eastern tip of Cuba to the Windward Passage.

Atlantic Ocean

A sharp upper trough reaches north of the Caribbean from over Bermuda through the northern Bahamas. This is supporting a surface trough along roughly 73W south of 25N. Another surface trough is analyzed along 63W south of 27N. Divergent flow aloft associated with the upper troughs supports scattered showers and isolated thunderstorms south of a line from 31N to the SE Bahamas and between 57W and 75W. Moderate to locally fresh easterly winds are noted south of 27N and west of 55W. Seas in these waters are 4-7 ft. Light to gentle winds and slight seas prevail north of 27N and west of 55W.

The remainder of the tropical Atlantic is dominated by a broad high pressure system near the Azores. The pressure gradient between the ridge and lower pressures in the deep tropics sustain moderate to locally fresh easterly winds and seas of 5-8 ft south of 20N and west of 30W. Moderate to fresh N-NE winds are occurring east of 25N and north of 13N. Seas in the area described are 4-8 ft. Elsewhere, moderate or weaker winds and moderate seas are prevalent.

For the forecast west of 55W, the gradient between high pressure over the western Atlantic and relatively lower pressure in the Caribbean Sea is allowing for generally moderate to fresh east winds to be south of about 25N, including the approaches to the Windward Passage. A surface trough is expected to soon form north- northeast of Hispaniola. The pressure gradient between the ridge and the trough will support pulsing strong east to southeast east of the trough, and moderate to fresh northeast to east winds west of the trough. Presently, an upper trough is over the western Atlantic. Numerous showers and thunderstorms are east of this trough. The trough is expected to help promote the formation of weak low pressure along the soon to form surface trough on Fri. The low will track east-northeastward Fri through Sat, and weaken back into a trough while exiting the area on Sun. High pressure will then take precedence over the entire area early next week. Moderate to fresh south winds are forecast to develop over the waters east of northeastern Florida Tue and Tue night.

Posted 2 hours ago by NHC Forecaster Delgado