Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Guinea-Bissau near 11N15W and continues southwestward to 04.5N32W. The ITCZ extends from 04.5N32W to 04N51W. Scattered moderate isolated strong convection is observed from 01.5N to 07.5N and east of 30W, and from 04.5N to 07.5N between 30W and 58W.

Gulf Of Mexico

A weak front is drifting eastward, and extends from the Florida Panhandle near Apalachicola to near 26N93W. Scattered moderate to isolated strong convection is noted within 120 nm SE of this boundary east of 92W. Overnight scatterometer satellite data indicated that strong winds are associated with the strongest convection. Meanwhile, strong thunderstorms have shifted westward off the Yucatan peninsula and across the eastern and into the central Bay of Campeche. Fresh southeasterly winds and seas of 4-7 ft are found north of Yucatan, south of 25N. Moderate or weaker winds and slight to moderate seas are prevalent in the remainder of the basin. A large area of haze and smoke due to agricultural fires in Mexico continues across most of the Gulf west of 87W and the Bay of Campeche.

For the forecast, active weather along and ahead of the front is being supported by a mid to upper-level trough across the southeast U.S. The front and associated weather will shift E-SE through Mon, when the front will dissipate across the SE Gulf. Ahead of the front, moderate to fresh return flow will prevail this morning then gradually diminish through Mon. Meanwhile, a large area of haze and smoke due to agricultural fires in Mexico continues across most of the western Gulf and Bay of Campeche. Moderate to locally fresh SE return flow will develop again across the W Gulf Tue through Thu night.

Caribbean Sea

The subtropical ridge over the Atlantic continues to extend westward along 24N/25N into the NW Bahamas. The pressure gradient between the aforementioned ridge and lower pressures in the deep tropics supports fresh to strong E to SE winds to 30 kt across the Gulf of Honduras, and fresh to locally strong trade winds in the south-central Caribbean, as confirmed by overnight scatterometer satellite data. These winds are sustaining seas of 6-9 ft, with the highest seas occurring off NW Colombia and the Bay Islands. Moderate to locally fresh easterly winds and seas of 4-7 ft are present in the north- central and eastern Caribbean. Elsewhere, moderate or weaker winds and slight to moderate seas prevail. Smoke due to agricultural fires in Central America continues across areas of the northwestern Caribbean and the Gulf of Honduras. A middle to upper-level trough lingers from the NE Caribbean to the SW basin, and is generally producing dry and stable conditions over the basin. However, scattered showers are seen across the extreme NE Caribbean and across SE portions south of 12N.

For the forecast, winds in the Gulf of Honduras will become moderate to fresh today through Mon as the pressure gradient weakens across the western basin. Fresh to strong winds will pulse at night in the Gulf of Venezuela and offshore Colombia through early Mon then shift eastward to offshore of NW Venezuela through Tue night. A vigorous middle to upper-level trough will dig southward across the western Caribbean Mon night through Thu, and support very active weather over central portions E of 80W Tue through Thu. Smoke due to agricultural fires in Central America continues across the Gulf of Honduras and areas of the northwestern Caribbean.

Atlantic Ocean

An upper level trough over the SE United States is supporting scattered showers and thunderstorms across the waters north of the NW Bahamas, ahead of a weak front across the NE Gulf of Mexico. Moderate to locally fresh S to SW winds and seas of 3-4 ft are occurring north of 28N and west of 76W. Farther east, a surface trough extends from 31N56W southwestward to 26N69W, while a narrow high pressure ridge extends E to W to the south of the trough along 24N/25N and into the NW Bahamas. E of the trough, scattered showers and isolated thunderstorms is observed north of 24N and between 47W and 55W. The rest of the tropical Atlantic is dominated by a broad subtropical ridge over the north Atlantic. Moderate to locally fresh NE to E winds and seas of 5-7 ft are evident south of the ridge, and generally south of 20N. Elsewhere, moderate or weaker winds and slight to moderate seas prevail.

For the forecast W of 55W, the surface trough will shift eastward through late Sun as it weakens further, allowing the ridge to build modestly into the region E of 72W Mon and Tue. Scattered showers and thunderstorms will move from the NW waters and offshore of NE Florida southeastward through this evening, ahead of an upper level trough. Behind this feature, a new front will sink southward into the waters offshore of Georgia and NE Florida early Mon, and move southeastward and stall from near 31N72W to SE Florida late Tue. A trough will develop southeast of the weakening front and extend into the central Bahamas early on Wed, and drift eastward through Thu night. Low pressure is expected to form along the trough near 24N68W Thu evening and move NE.

Posted 2 hours ago by NHC Forecaster Stripling