Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic along the coast of Guinea-Bissau just south of Bissau and extends south-southwestward to 05N18W, where it transitions to the ITCZ to 02N30W to south of the Equator at 43W and to near the Amazon Delta region. Scattered moderate convection is within 30 nm north of the ITCZ between 19W-23W.

Gulf Of America

A ridge extends southwestward from a 1023 mb high near the Florida Big Bend area to south of Tampico, Mexico. Moderate to fresh southeast winds along with seas of 4 to 6 ft are present in the eastern Bay of Campeche and extending northward to near 24N. Latest scatterometer satellite data indicates gentle to moderate east to southeast winds and seas of 3 to 5 ft over the rest of the basin, except for slightly lower seas of 2 to 4 ft in the southeastern part of the Gulf.

For the forecast a ridge across the northern Gulf will remain in place and slowly weaken through Sat, maintaining gentle to moderate east to southeast winds across most of the basin. The exception will be off the Yucatan Peninsula, where a daily trough will allow fresh to strong winds to pulse during the evenings. Looking ahead, fresh to strong north to northeast winds and building seas will follow a cold front moving across the northern Gulf Sat night through the early part of the week. The front will stall from the Straits of Florida to South Texas by late Mon and dissipate through Tue.

Caribbean Sea

A mid to upper-level low dropping southward over the north- central Dominican Republic is helping to sustain scattered showers and isolated thunderstorms near the Dominican Republic and ABC Islands as well as over sections of the northeastern Caribbean, including Puerto Rico and vicinity waters. A surface trough extends from the western Atlantic to eastern Haiti. Otherwise, a modest trade-wind regime is present across most of the sea. Moderate to locally fresh east-northeast to east-southeast winds along with seas of 4 to 6 ft are in the lee of Cuba, near the Windward Passage and near the ABC Islands. Latest scatterometer satellite data shows gentle to moderate east-southeast winds elsewhere across the basin. Seas are about 2 to 4 ft with these winds.

For the forecast, the aforementioned mid to upper-level low is expected to become absorbed into a trough by early on Fri as the trough shifts eastward toward the northeastern Caribbean. The surface trough will disrupt the typical pressure pattern across the basin during this time. Expect fresh trade winds and moderate seas off the coast of Colombia overnight, then mainly gentle to moderate winds are expected there during the remainder of the week. Winds and seas will generally diminish across the basin as the trough passes north of the area Fri through the weekend. Looking ahead, expect fresh northeast winds early next week across the Windward Passage associated with a late-season cold front moving across Cuba.

Atlantic Ocean

A mid to upper-level trough curves southwestward from southeast of Bermuda to 24N60W, to a mid to upper-level low over the north- central Dominican Republic, and southwestward from there to the southwest Caribbean. A surface trough extends from 31N63W to the Turks and Caicos and to eastern Haiti. Scattered showers and isolated thunderstorms are seen from 20N to 22N between 67W and 71W, and from 22N to 24N between 65W and 69W. Refer to the Monsoon Trough/ITCZ section at the beginning for additional convection in the Atlantic Basin.

A 1023 mb high center is analyzed north of the area at 34N68W while a 1025 mb high center is just north of the area at 32N49W. High pressure continues to dominate the wind flow pattern across the basin, generally north of about 18N and east of the Lesser Antilles and also north of 21N and west of 61W. The related gradient is providing for light to gentle winds north of 26N between 35W and the Florida/southern Georgia coast. Seas are 4 to 6 ft over these waters. Farther south from 20N to 26N and between 35W and the Bahamas, gentle to moderate northeast to east winds are present along with seas of 6 to 8 ft. Moderate to fresh northeast to east winds and seas of 5 to 7 ft mainly in an east swell prevail for the remainder of the Atlantic Basin.

Three other surface troughs are analyzed over the basin, however, no deep convection is presently occurring with these features.

For the forecast west of 55W, the surface trough extending from eastern Haiti to the Turks and Caicos to southwest of Bermuda will move little through Fri, then dissipate through Sat. High pressure will build into the area from the east following the trough. Looking ahead, a cold front is forecast to move off the coast of northeast Florida Sun night. Expect fresh to strong N to NE winds and building seas in the wake of the front as it reaches from Bermuda to the Straits of Florida by late Mon, and from 31N60W to central Cuba by late Tue.

Posted 44 minutes ago by NHC Forecaster Aguirre