Monsoon Trough Itcz

The monsoon trough enters the Atlantic along the coast of Sierra Leone near 08N13W and extends southwestward to 04N17W, where it transitions to the ITCZ and continues to NE Brazil near 02S44W. Scattered moderate to isolated strong convection is noted south of 04N between 10W and 40W.

Gulf Of America

A ridge extends across the SE of the United States into the Gulf region. The associated pressure gradient is supporting moderate to fresh NE to E winds over the eastern Gulf with seas of 5 to 8 ft. Gentle to moderate E to SE winds and moderate seas are occurring over the western Gulf. A few showers with isolated thunderstorms are currently noted mainly over the NW and SE parts of the basin.

For the forecast, strong high pressure over the eastern U. S. will support moderate to fresh northeast winds and moderate seas across the Gulf through the middle of next week. The exception will be on Monday, when strong east winds will develop across the eastern half of the basin. Scattered showers and thunderstorms are moving across the NW Gulf in the offshore waters of Texas. This activity may hold together through tonight.

Caribbean Sea

The pressure gradient between the strong ridge over the eastern United States and lower pressures in northern South America results in fresh to strong trade winds and seas of 6 to 9 ft across the south-central Caribbean. Moderate to locally fresh easterly winds and moderate seas are found in the north-central, SW and eastern Caribbean. Elsewhere, moderate or lighter winds and seas of 2 to 4 ft prevail. Scattered showers and thunderstorms are flared-up over easter Cuba, Jamaica and Hispaniola likely associated with the southern end of a cold front over eastern Cuba and a surface trough over Hispaniola. Elsewhere, shallow moisture embedded in the trade wind flow is moving across the basin producing brief showers.

For the forecast, strong high pressure building southward from the western Atlantic will tighten the pressure gradient and increase winds over the basin, leading to strong winds over the south-central Caribbean through the weekend and into early next week. Fresh to strong northeast winds and building seas will prevail south of Cuba, in the Windward Passage, and south of Hispaniola starting on Sat night.

Atlantic Ocean

A cold front extends from just E of Bermuda to eastern Cuba. A band of showers and thunderstorms is ahead of the front, mainly N of 22N. The tight pressure gradient between this front and the ridge over the eastern United States sustains fresh to strong NE winds and rough seas up to 12 ft behind the front. Moderate to fresh southerly winds and rough seas are evident N of 27N ahead of the front to about 55W. The remainder of the Atlantic forecast area is under the influence of an extensive subtropical ridge anchored by a 1034 high pressure located SW of the Azores near 34N37W. Fresh to strong easterly trade winds and rough seas are observed under the influence of the ridge, particularly N of 15N and E of 55W. Elsewhere, moderate winds and moderate seas prevail.

For the forecast west of 55W, strong high pressure is building southward north of the aforementioned front. The pressure gradient between these two features will maintain strong northeast through tonight, then mostly fresh wind speeds will prevail until Sun. Rough seas from large northeast swell will linger into the start of next week between Bermuda and the Bahamas. Fresh to strong northeast winds are expected early on Sun and continue through early next week as the pressure gradient tightens across the area.

Posted about 6 hours ago by NHC Forecaster GR