Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic along the coast of Africa near 10N14W, and continues southwestward to 07N19W, where it transitions to the ITCZ and continues to 05N24W to 06N34W to 05N41W and to near 06N51W. Scattered moderate convection is seen within 90 to 120 nm north of the ITCZ between 21W and 31W, and within 60 nm south of the ITCZ between 22W and 27W.

Gulf Of America

A trough is analyzed over the southwestern Gulf from near 23N95W to 20N95W and to just inland Mexico at 19N95.5W. Scattered showers and thunderstorms are noted within about 60 nm east of the trough from 18.5N to 20N. Isolated showers are over the eastern Bay of Campeche. Otherwise, the gradient related to a surface ridge stretching southwestward from a 1025 mb high over southeastern Georgia to near Tampico, Mexico is generally supporting gentle to moderate winds and seas of 2 to 4 ft across the basin, except for slightly higher seas over the central, west-central and southeastern sections of the Gulf, including the Straits of Florida.

For the forecast, moderate or weaker winds and slight seas will prevail over much of the Gulf through this evening. High pressure will build across the eastern United States through the day. This will tighten the pressure gradient across the Florida Straits, bringing an increase in winds. Fresh winds will develop over those waters tonight, and will strengthen Monday into late Tue. Rough seas will develop with the strong winds.

Caribbean Sea

High pressure ridging extends from the western Atlantic to the northwestern and north-central Caribbean. The pressure gradient between the high pressure and relatively lower pressure in northern Colombia is allowing for mostly moderate to fresh trade winds across the basin, with the exception of fresh to strong northeast to east winds near and offshore Colombia. Seas are in the range of 4 to 6 ft, except for slightly higher seas of 5 to 7 ft from 15N to 18N between 72W and 80W and higher seas of 7 to 10 ft south of 15N between 76W and 81W. Seas of 6 to 8 ft in northeast swell are south of 11N west of 80W.

Patches of low-level moisture, with possible isolated showers, are moving westward with the trade wind flow mostly north of 15N.

For the forecast, the fresh to strong northeast to east winds off Colombia will pulse to near gale-force speeds at night during the week. Rough seas are expected with these winds. High pressure will move off the coast of the United States in the wake of a cold front over the southwestern north Atlantic waters early this week. This will tighten the pressure gradient over the waters in the lee of Cuba, south of Hispaniola, and in the Windward Passage. Moderate to fresh NE winds over these waters will strengthen by Mon evening, and continue through Thu night. Otherwise, mixed long period swell over the tropical Atlantic waters will subside Mon evening. New long-period northerly swell will affect the tropical Atlantic waters Wed and Thu.

Atlantic Ocean

A weakening stationary front extends southwestward from the north-central Atlantic across 31N62W to the NW Bahamas. Scattered showers are noted near and up to 75 nm northwest of this boundary. To the east of the stationary boundary, a trough is analyzed from near 31N50W to 27N55W and to near 23.5N63W. Scattered showers and a few thunderstorms are within 300 nm east of the trough north of 29N. Farther east, a trough extends from 28N36W to 22.5N30W. No significant convection is noted with this feature. Another trough extends from near 20N54W to 14.5N52W. Isolated light showers are near the trough from 17N to 20N.

Latest scatterometer satellite data passes show moderate to fresh trade winds over the eastern and central sections of the basin south of 28N east of 44W and south of 22N between 44W and 77W. Seas are 6 to 8 ft in northeast to east long-period swell over these areas, with the exception of higher seas in the range of 8 to 10 ft in mixed north and east swell north of about 15N and east of 40W. Winds elsewhere are light to gentle, mostly northeast to east in direction, along with seas of 4 to 7 ft also in long-period northeast to east swell. An area of moderate northeast winds is east of the Bahamas to near 72W from 24N to 26N. Seas are 5 to 6 ft with these winds.

For the forecast W of 55W, moderate to occasionally fresh trade winds will continue south of 22N into Mon. A cold front will move into the northern waters early this week and will rapidly progress eastward through midweek. Widespread strong to locally near-gale force NE winds and rough seas are expected in the wake of the front. Very rough seas in excess of 12 ft will be possible east of 75W Tue through midweek, most likely leading to significant swell event. A second cold front may enter the northern waters by around the middle of the week, with strong winds and building seas in the wake of the front east of 70W.

Posted 1 hour, 50 minutes ago by NHC Forecaster Aguirre