Tropical Waves

A tropical wave is along 33W S of 17N, moving W at 10 to 15 kt. Convection is described in the Monsoon Trough/ITCZ section below.

An Atlantic tropical wave is near 41W and S of 18N, moving W at 10 to 15 kt. Convection is described in the Monsoon Trough/ITCZ section below.

An Atlantic tropical wave is near 50W south of 19N, moving W at around 15 kt. Convection is described in the Monsoon Trough/ITCZ section below.

A Caribbean tropical wave is near 79W, south of 19N, moving W at at 10-15 kt. Scattered moderate convection is active from 09N to 20N between 80W and 87W.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic near 20N16W to 10N20W. Segments of the ITCZ extend from 10N22W to 08N32W, from 06N33W to 06N40W, from 07N42W to 07N50W, and from 07N52W to 06N57W. Scattered moderate convection is noted within 240 nm on either side of the ITCZ and west of 25W.

Gulf Of America

The subtropical ridge extends across the Florida Peninsula and across the northern Gulf to the coast of Texas. A surface trough reaches from Mobile Bay, Alabama to Tampa, Florida. Scattered showers and thunderstorms are active off the western Florida Panhandle along this trough. Scattered showers and thunderstorms are also active over the southeast Gulf, under divergent flow aloft. Farther south, a weak trough is positioned over the Bay of Campeche. This pattern is supporting fresh NE winds off the west coast of the Yucatan Peninsula, as noted in a recent scatterometer satellite pass. Gentle to moderate breezes are observed elsewhere. Seas are generally 1-3 ft across the basin.

For the forecast, surface ridging is forecast to prevail across the basin through the forecast period, thus supporting gentle to moderate winds over the western half of the Gulf, except for locally fresh to strong ENE winds offshore the Yucatan peninsula at night. Locally moderate or weaker winds are forecast for the eastern half of the Gulf while mainly slight seas are forecast basin-wide.

Caribbean Sea

The subtropical ridge extending north of the area across the western Atlantic is supporting moderate to fresh trade winds across the eastern and central Caribbean, with strong E winds noted off northeast Colombia and northwest Venezuela. Seas are 7-10 ft over the south-central Caribbean in the area of strongest trade winds, and 6-7 ft elsewhere east of 80W. A recent scatterometer satellite pass indicated fresh to strong easterly winds across the Gulf of Honduras, likely related to scattered showers and a few thunderstorms active in that area, associated with divergent flow aloft on the east side of an upper low centered over the Yucatan Peninsula. Seas across the Gulf of Honduras are 4-6 ft, and 2-4 ft elsewhere over the northwest Caribbean.

For the forecast, the pressure gradient between the Atlantic ridge north of the basin and the Colombian Low will continue to support fresh to strong trade winds and moderate to rough seas over the central Caribbean through the weekend. The aerial extent of these winds will continue to increase today as the Atlantic ridge continues to build westward. By Wed, the fresh to strong winds are expected to extend across most of the east, central and SW Caribbean. Expect winds to reach near-gale force at night offshore of Colombia and in the Gulf of Venezuela through Fri. Moderate or weaker winds will prevail over the NW part of the basin, except in the Gulf of Honduras where fresh to locally strong E to SE winds are forecast at night through the forecast period.

Atlantic Ocean

The Atlantic subtropical ridge dominates the Atlantic north of 20N, and is anchored by 1025 mb high pressure centered near 29N39W. The pattern is supporting gentle to moderate breezes and 3-5 ft seas along and west of the ridge axis, and moderate to fresh NE to E trade winds and 5-7 ft seas east and south of the ridge axis. Upper divergent flow is supporting a few showers and thunderstorms from 25N to 30N 45W and 70W.

For the forecast west of 55W, the Atlantic subtropical ridge will stay in place through the forecast period, developing a center of high pressure E of the Bahamas by Fri. This pattern will continue to support moderate to fresh E to SE trade winds S of 23N, and moderate or weaker winds elsewhere. Locally strong winds, with moderate to rough seas are expected at night north of Hispaniola, including approaches to the Windward Passage, through Fri night.

Posted 0 minutes ago by NHC Forecaster Christensen