Tropical Waves

An eastern Atlantic tropical wave is along 29W, from 02N to 19N, moving westward at 10-15 kt. Any nearby convection is described with the Monsoon Trough/ITCZ section below.

A central Atlantic tropical wave is along 49W, south of 17N, moving westward at around 20 kt. Scattered showers and thunderstorms are seen from 07N to 13N between 46W and 57W.

An eastern to central Caribbean tropical wave is along 71W, south of 20N near the western Dominican Republic to western Venezuela, moving westward at around 15-20 kt. No significant convection is seen near this wave.

Monsoon Trough/ITCZ

The monsoon trough reaches the Atlantic from Mauritania at 19N17W to 09N22W to 12N36W. The ITCZ extends from 12N36W to 09N47W where it is broken by a tropical wave. The ITCZ then resumes from 07N50W to 06N54W. Scattered showers and isolated thunderstorms are seen from 06N to 11N between 25W and 30W.

Gulf Of America

A persistent surface trough is from near Naples, Florida to the eastern Gulf near 26N87W. Clusters of scattered moderate to strong convection are noted N of 26N and E of 86W. Otherwise, 1014 mb high pressure near 27N91W controls the basin with gentle to moderate or weaker winds prevailing across much of the Gulf and away from areas of convection, except for the SW Gulf where a surface trough is driving moderate to fresh E winds. Seas are 1 to 3 ft across the basin.

For the forecast, a surface ridge will remain in control of the weather pattern across the Gulf region promoting gentle to moderate winds for the next several days. The exception will be fresh NE winds off the northwest coast of the Yucatan peninsula nightly into the weekend. A trough extends from Tampa, Florida to 26N86W while a mid to upper level broad trough north of the area is slowly advancing southward toward a very moist and unstable Gulf airmass. This set-up will maintain scattered showers and thunderstorms mainly over the NE Gulf through the rest of the week.

Caribbean Sea

A mid to upper level feature is supporting moderate convection in the NW Caribbean just southeast of the Yucatan Channel. Otherwise, high pressure at the surface over the central Atlantic and low pressure over northern Colombia supports the typical fresh to strong trades across the basin from 11N to 18N including the Gulf of Honduras, except locally near gale force near northern Colombia. Gentle to moderate winds are elsewhere. Seas are 5 to 8 ft from 10N to 18N to the east of 80W, and mainly 3 to 5 ft elsewhere except lower in the lee of Cuba. Seas are locally 8-10 ft offshore N Colombia.

For the forecast, the coverage area and strength of the trades will increase on Thu as the pressure gradient between the Atlantic ridge and the Colombian Low increases. By that time, expect fresh to strong winds and moderate to rough seas across most of the eastern and central Caribbean, with the strongest winds to near gale, or possible brief gusts to gale and highest seas offshore Colombia. Fresh winds are expected to pulse in the Gulf of Honduras nightly through Fri.

Atlantic Ocean

A frontal trough extends from near Bermuda to the NW Bahamas. Divergence aloft associated with an upper-level trough north of our waters supports scattered showers and isolated thunderstorms N of 28N and W of 75W. The remainder of the basin is under the influence of a broad subtropical ridge anchored by a 1025 mb high pressure system near 30N51W.

The pressure gradient between the aforementioned ridge and frontal trough support fresh to strong S-SW winds and seas of 6 to 9 ft north of 28N and west of 65W. Moderate to locally fresh easterly winds and seas of 5 to 7 ft are noted north of the ITCZ and monsoon trough to 20N and west of 40W, with locally strong E winds E of the Lesser Antilles to about 60W. In the far eastern Atlantic, fresh to strong N to NE winds and seas of 4 to 7 ft are evident from 15N to 30N and east of 20W. Elsewhere, moderate or lighter winds and slight to moderate seas are prevalent.

For the forecast west of 55W, the Bermuda High will maintain a ridge farther south than usual, roughly along 25N, through Fri. This, in combination with a frontal trough over the western Atlantic, will support fresh to strong SW winds along with scattered showers and thunderstorms primarily north of 27N and west of 70W for the next several days. Fresh to strong trades will pulse just north of Hispaniola at night and into the mornings through the upcoming weekend.

Posted 23 minutes ago by NHC Forecaster Adams