Monsoon Trough/Intertropical Convergence Zone

The monsoon trough axis enters the Atlantic Ocean through the coast of Liberia near 06N10W and continues west-southwestward to near 04N16W, where it transitions to the ITCZ axis to the Equator at 30W and west-southwestward to just inland the coast of Brazil at 02S46W. Scattered moderate to isolated strong convection is seen within 180 nm north of the ITCZ between 28W and 32W. Scattered moderate convection is within 120 nm north of the ITCZ between 32W and 38W.

Gulf Of America

The western periphery of Atlantic high pressure stretches westward along 33N to across the southern United States. The associated gradient is allowing for gentle to moderate southeast return flow over the basin. Seas are in the 3 to 6 ft range. Scattered moderate convection moving eastward is over most of north-central and northeastern Florida. It is primarily being driven by a mid-level shortwave trough as seen in water vapor imagery. Similar activity moving eastward is over the western Florida panhandle and over extreme southern Alabama and southeastern Mississippi.

Patchy to areas of dense sea fog are expected to develop tonight and into Mon morning, and possibly again on Mon night, along some sections of the Texas and southwest Louisiana coasts limiting visibility to 1 nm or less.

For the forecast, the aforementioned western Atlantic ridge will dominate the Gulf weather pattern through Mon, producing a gentle to moderate return flow and slight to moderate seas. A weak cold front is forecast to sink into the NW and north- central Gulf coastal waters late on Mon, and extend from the Florida Big Bend to SE Texas by Tue morning before lifting north and dissipating. High pressure will then build westward across the Gulf Tue night through Fri to support fresh to strong southeast to south winds across most of the basin and moderate to rough seas.

Caribbean Sea

The pressure gradient between the Bermuda High north of the area and a 1008 mb Colombian Low is resulting in fresh to strong trades over the central and northeastern sections of the basin. Strong to near gale-force winds are just north of Colombia. Trades elsewhere are in the gentle to moderate range as seen in the most recent scatterometer satellite data passes. Seas are 7 to 10 ft north of Colombia and 4 to 7 ft elsewhere. No significant deep convection is presently observed.

Scattered showers and thunderstorms are weakening over some areas of central and eastern Cuba.

For the forecast, high pressure centered east of Bermuda will combine with the Colombian low to support fresh to strong trade winds and moderate to rough seas off the coast of Colombia through the middle of the week. Similar wind speeds are also expected in the Gulf of Honduras through Wed. Large E swell will continue to impact the Tropical Atlantic waters and Caribbean Passages most of the week, maintaining seas of 8 to 10 ft. Looking ahead, high pressure will again become re-established north of the Caribbean Sea Wed afternoon through Fri night and bring about a significant increase in winds and seas across most of the basin.

Atlantic Ocean

A trough, remnants of a former stationary front, extends from near 31N41W southwestward to 24N5W. No deep convection is noted with this feature, however, scattered to broken low clouds with possible isolated showers are north of 28N between 41W and 49W. Similar clouds also with possible isolated showers are seen from 25N to 28N between 49W and 65W. These clouds are moving westward. A trough in the eastern Atlantic extends from a 1010 mb low that is north of the area near 33N22W southwestward to 23N29W. Fresh winds are located north of 28N on both sides of the trough. Seas are 8 to 10 ft in NE long-period swell north of 25N between 25W and 33W. Elsewhere, a moderate pressure gradient between high pressure of 1029 mb located just north of the area east of Bermuda near 32N59W and relatively lower pressure in the ITCZ region is producing fresh to strong trades south of 27N east of 72W as noted by the latest scatterometer satellite data passes. Seas with these winds are 8 to 10 ft in long-period northeast to east swell. Elsewhere, latest scatterometer satellite data passes generally indicate gentle to moderate east to southeast winds, except for gentle to moderate northeast to east winds north of 27N between 50W and 64W, gentle to moderate east to southeast winds north of 27N between 64W and 72W, and moderate to fresh east to southeast winds west of 72W. Seas elsewhere are 7 to 9 ft in long-period east swell, except for lower seas of 4 to 7 ft north of 29N west of 55W.

Satellite imagery reveals scattered to numerous thunderstorms over the waters offshore the Florida peninsula from 25N to 30N. This activity is being aided by a mid-level shortwave trough that is crossing the Florida peninsula from west to east.

For the forecast west of 55W, a ridge extends westward along 33N from high pressure that is centered east of Bermuda. The high will move slowly eastward and weaken some through Mon night. As a result, winds and seas will diminish modestly across the forecast area Mon afternoon through Mon night. A cold front will move off the southeastern United States coast late Tue and weaken quickly across the far northwest zones early Wed. High pressure will then build southward again across the region Wed night through Fri, bringing an increase in winds and seas, mainly over the waters south of 24N.

Posted 1 hour, 2 minutes ago by NHC Forecaster Aguirre