Special Features

Caribbean Gale Warning: The pressure gradient between the Atlantic high pressure ridge extending from the central Atlantic west- northwestward to north Florida and the NE Gulf of America, and lower pressures over northern South America, will continue to support strong to near gale-force easterly trade winds over the south- central Caribbean, including the Gulf of Venezuela, into early next week. Morning satellite scatterometer data showed winds near gale-force off the north coast of Colombia, where satellite altimeter data showed seas of 12 to 15 ft. Winds and seas have since diminished slightly across that area. Winds are forecast to pulse to gale- force off the coast of Colombia again tonight through Sun morning. Rough to very rough seas of 12 to 14 ft are expected with these winds.

Please refer to the latest NWS High Seas Forecast at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.

Tropical Waves

A tropical wave has entered the Caribbean, along 61W-62W, south of 18N, moving westward around 15 kt. Scattered squalls and moderate thunderstorms are seen moving across the SE Caribbean, Windward Islands, and adjacent Atlantic waters south of 14N between between 55W and 64W.

A Caribbean tropical wave has entered the Yucatan Peninsula and is now along about 88W, south of 21N and into the eastern Tropical Pacific, moving west near 15 kt. Scattered moderate to strong convection is south of 20N, extending from 84.5W westward across the Gulf of Honduras and adjacent waters and well inland.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Mauritania near 19N16W and continues southwestward to 09N31W. The ITCZ extends from 09N32W to 06N51W to the coast of Guyana near 07.5N59W. Scattered moderate isolated strong convection is occurring from 08N to 12N and between 15W and 27W. Scattered moderate convection is noted from 06N to 10N between 31W and 57W.

Gulf Of America

The western Atlantic surface ridge extends west-northwestward across north Florida and the Florida Big Bend today. Associated southeasterly low level flow continues to transport areas of abundant low level moisture into the basin. Clusters of scattered showers and isolated thunderstorms extends from the SE Louisiana southward to near 26N, and area also about the Texas coastal waters. Overnight convection across the Florida Straits and SE Gulf has diminished in intensity, however scattered moderate showers persist there. The subtropical ridge is supporting light to gentle winds and seas of 2-4 ft across the waters east of 88W. Gentle to moderate SE to S winds generally prevail west of 88W, where seas are also 2-4 ft.

For the forecast, a frontal boundary will approach the northern Gulf coast this weekend, enhancing thunderstorm activity across the area into early next week. Mariners should expect gusty winds, frequent lightning, and higher seas near the strongest thunderstorms. Elsewhere, high pressure will dominate into next week, supporting mainly gentle to moderate SE winds. However, fresh to strong easterly winds will pulse offshore the Yucatan Peninsula each night.

Caribbean Sea

Please refer to the Special Features section above for details on gale conditions forecast for offshore Colombia. The pressure gradient south of the western Atlantic ridge to the north is supporting mostly strong trade winds south of 17.5N between 67W and 80W, based on morning satellite scatterometer data. Seas are 8 ft 15 ft across this area. Fresh to locally strong E-NE trade winds accompany the tropical wave entering the Caribbean this morning, and extend to the east of the wave axis and into the Tropical Atlantic east of the Lesser Antilles. Squalls and thunderstorms are ahead of the tropical wave in the SE Caribbean. Seas across this area are 6-8 ft.

Divergence aloft and abundant tropical moisture accompanying the tropical wave continues to producing scattered showers and thunderstorms over the NW Caribbean west of 84.5W. Similar convection is noted in the SW Caribbean, from western Panama to southeast Nicaragua.

For the forecast, high pressure north of the islands and lower environmental pressures over northern South America combine to support strong to near gale-force easterly trades and rough seas over the central Caribbean, including the Windward Passage. This pattern will persist into next week. Winds will pulse to gale- force off Colombia tonight. Trades over the Gulf of Honduras will pulse to strong each evening through the forecast period. Finally, moderate to locally fresh easterly breezes and moderate seas are expected in the eastern Caribbean into next week.

Atlantic Ocean

A persistent upper level low pressure system over the SE Bahamas and eastern Cuba is combining with abundant tropical moisture surging northwestward across the Bahamas and into south Florida to produce scattered showers and thunderstorms across the NW Bahamas, The Florida Straits, and nearby waters. A squall line is seen northeast of Abaco moving northeastward. Farther east, divergence aloft and a frontal trough just north of our area extending southwestward to near 27N60W support scattered showers and isolated thunderstorms north of 26N and between 53W and 61W. The rest of the tropical Atlantic is under the influence of a broad subtropical ridge that sustains fresh to strong easterly trade winds and moderate seas, except for locally rough seas to 8 ft off Haiti and eastern Cuba, and across the waters east of the Lesser Antilles. Elsewhere, moderate or weaker winds and moderate seas prevail.

For the forecast west of 55W, an upper level low pressure currently over the NW Bahamas will move westward through the weekend, supporting thunderstorms with locally strong winds, frequent lightning and higher seas. Meanwhile, the subtropical ridge will remain dominant through the period, supporting moderate to fresh trades south of 23N, with mainly gentle winds to the north. Pulsing strong and locally rough seas winds are expected each night offshore Hispaniola and in the Windward Passage.

Posted 2 hours ago by NHC Forecaster Stripling