Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic near 11.5N16W and continues southwestward to 11N18.5W. The ITCZ extends from 11N18.5W to 09N58W. Scattered moderate convection is occurring east of 30W from 05N to 20N, with fresh to strong NE winds occurring in the strongest convection. Scattered showers and isolated thunderstorms are also occurring W of 50W between 15N and the coast of South America.

Gulf Of America

A weak stationary front extends from the Big Bend of Florida to near 29N86W, where it transitions to a warm front that extends into SE Louisiana. No significant convection is seen with these fronts.

For the forecast, a cold front is approaching the NW Gulf waters, along with strong showers and thunderstorms. A warm front is lifting northward over the NE Gulf ahead of the aforementioned cold front. Expect fresh southerly flow off the Texas coast tonight supported by the gradient between low pressure over northeast Mexico and high pressure off the Carolinas. These winds will diminish Tue ahead of the aforementioned cold front. A stronger reinforcing cold front will overtake the frontal boundary early Wed, then move into the NW Gulf. The cold front will then sweep to the southeast of the basin by Thu night into Fri, followed by fresh to strong northeast winds and building seas into the weekend. Scattered showers and thunderstorms may accompany the frontal boundary.

Caribbean Sea

Divergence aloft continues to support widely scattered showers and isolated thunderstorms in the Gulf of Honduras, as well as off Costa Rica, Panama, and NW Colombia. This latter area of convection is likely enhanced by the East Pacific monsoon trough which also extends across the SW Caribbean. Fresh to strong NE winds prevail in the central Caribbean, strongest offshore northern Colombia. Seas in these waters are 6-9 ft, as confirmed by an earlier altimeter pass. Moderate to locally fresh NE to E winds and mainly moderate seas are noted elsewhere.

For the forecast, the pressure gradient between a ridge north of the islands and lower pressures in NW Colombia will sustain fresh to strong trade winds and rough seas in the central Caribbean through late this week. The strongest winds of 25 to 30 kt, and highest seas of 10 to 13 ft are expected offshore Colombia mainly at night. In the remainder of the basin, the weather pattern will support moderate to fresh winds along with moderate seas through the period. Looking ahead, a cold front will enter the NW Caribbean on Fri, followed by strong winds and rough seas.

Atlantic Ocean

A weak cold front extends from near 31N60W to near 27N77W, where it becomes a stationary front that extends to near Cape Canaveral, FL. No significant convection is noted near the front. Moderate to fresh NE winds and seas of 4-6 ft follow these fronts. Farther east, a weak 1016 mb low pressure is near 30.5N48W. A surface trough extends from this low to 21N48W. Scattered showers and isolated thunderstorms are present north of 21N between 43W and 49W. In the east Atlantic, a surface trough is analyzed from 29N21W to 26N25W to 21N26W to 16N30W. More scattered showers and thunderstorms are ongoing between the trough axis and the west coast of Africa. Recent scatterometer data indicates fresh to locally strong winds N of the trough, driven by the pressure gradient between the trough and high pressure to the north.

Elsewhere across the Atlantic away from the aforementioned features, moderate to fresh trades and moderate seas prevail across the vast majority of the basin. The exceptions are two regions, one north of 20N between 35W and 65W, and the other in the vicinity of the Canary Islands, where gentle to moderate trades and seas of 2-5 ft prevail due to weaker pressure gradients in these areas.

For the forecast west of 55W, a weak cold front extends from 31N60W to near Cape Canaveral, Florida. The eastern portion of the front will continue eastward and reach from 31N52W to 27N63W by Tue morning, while the portion west of 70W starts to lift north. High pressure located off the Carolinas will shift eastward following the front, supporting moderate to fresh northeast to east winds and moderate seas over the region. Looking ahead, winds and seas will diminish west of 70W by Wed, ahead of a stronger cold front expected to move off the northeast Florida coast Wed night. The front will reach from Bermuda to the Straits of Florida by early Fri, followed by fresh to strong NW winds and building seas through Fri night. Looking ahead, a tightened pressure gradient in the wake of the front is forecast to bring increasing winds and building seas across much of the forecast area during the upcoming weekend.

Posted 11 minutes ago by NHC Forecaster Adams