Tropical Waves

A tropical wave is W of the Cape Verde Islands near 30W, extending from 03N to 17N, and moving W at around 15 kt. Scattered showers and isolated thunderstorms are seen from 06N to 11N between 29W and 34W.

A tropical wave is across the eastern Caribbean, south of 19N, moving W at 10-15 kt. Scattered moderate isolated strong convection is noted from 10N to 16N between 61W and 70W.

Monsoon Trough Itcz

The monsoon trough enters the Atlantic near 16. 5N16. 5W and continues southwestward to 08N34W. The ITCZ extends from 08N34W to 05. 5N54W. Aside from the convection associated with the tropical waves, scattered moderate convection is evident within 60 nm N and 120 nm S of the ITCZ between 34W and 54W.

Gulf Of America

High pressure extends a ridge across the western Atlantic SW across the SE U. S. and to the central Gulf waters, anchored by a 1019 mb high in the central Gulf. This supports light to gentle winds and slight seas across most of the basin, except for gentle to moderate E to SE winds over the Bay of Campeche associated with a surface trough. Aside from the moderate winds, the surface trough in the Bay of Campeche is generating scattered showers and isolated thunderstorms in the SW Gulf, while scattered showers extend across the NE Gulf.

For the forecast, a weak surface ridge will continue to dominate the Gulf waters through the forecast period supporting gentle to moderate winds over the western Gulf and light to gentle winds over the eastern Gulf. The exception will be pulsing winds reaching fresh to locally strong speeds off the northwestern Yucatan Peninsula nightly through early next week. Slight to moderate seas are expected through the period.

Caribbean Sea

Abundant tropical moisture accompanying the tropical wave along 65W has encountered favorable upper level conditions produce by an elongated middle to upper-level low pressure just N of the Greater Antilles to produce scattered showers and thunderstorms across much of the eastern Caribbean east of 70W. This upper level feature is also supporting strong scattered afternoon convection across Hispaniola and Cuba. The pressure gradient between the subtropical ridge north of the basin and the Colombian Low continue to support fresh to strong easterly winds and seas of 8-11 ft in the central to SW Caribbean. The strongest winds and highest seas are found off NW Colombia. Moderate to fresh easterly winds and moderate seas are occurring in the eastern Caribbean away from areas of convection associated with the tropical wave near 65W. Seas are 4 to 6 ft there. Elsewhere, moderate or lighter winds and slight to moderate seas prevail. The E Pacific extension of the monsoon continues to support scattered strong convection over the waters near the coasts of Costa Rica and Panama.

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 Tue night. Expect winds to reach near- gale force each night offshore of Colombia and in the Gulf of Venezuela. Otherwise, moderate to fresh trades will continue in the eastern Caribbean while moderate or weaker winds will prevail over the NW part of the basin. Active showers and thunderstorms are expected across the SE Caribbean tonight accompanying the tropical wave along 65W. The wave and its associated moisture will reach Hispaniola and the central Caribbean waters on Sat.

Atlantic Ocean

A weakening frontal boundary continues to meander just north of the area along 32N-33N between 57W and 73W. A surface trough, remnants of a stationary front, extends from a 1018 mb low pressure near 32N73W to the SE FL coast. Scattered showers and a few thunderstorms are seen along and near the trough axis, while scattered showers and thunderstorms previal across much of the central and northwestern Atlantic between the stalled front and 27N, from 46W to 72W, and focused along another surface trough from 31N66W to 29N60W to 30N56W. A middle to upper-level low north of the Dominican Republic is also aiding in the development of strong scattered showers and isolated thunderstorms across Hispaniola and Cuba. Otherwise, the Azores High extends a ridge southwestward across the subtropical Atlantic waters, thus supporting mainly moderate to fresh trades and moderate seas across much of the waters S of 20N. Fresh to locally strong trades prevail across areas from 10N to 15N between 50W and the Lesser Antilles, where seas are 6 to 8 ft. Gentle to moderate trades and 3-6 ft seas prevail across much of the remaining Atlantic.

For the forecast west of 55W, a surface trough across the NW waters to SE Florida will gradually dissipate tonight while drifting northwestward toward the southeastern U. S. coast. The Atlantic ridge will then build westward into central Florida through early next week. This pattern will support moderate to fresh E to SE trade winds S of 22N, and moderate or weaker winds elsewhere.

Posted about 3 hours ago by NHC Forecaster Stripling