Special Features

Central Atlantic Gales and Significant Swell: A strong cold front curves west-southwestward from east of Bermuda across 31N62W to beyond 31N77W. It will bring W to NW near-gale to gale-force winds across the central Atlantic, north of 29N between 56W and 62W tonight through early Thu morning. In addition, large NW swell behind the cold front will cause 12 to 15 ft seas north of 30N between 57W and 67W late tonight. Seas are expected to build higher to between 12 and 20 ft and spread to 27N between 53W and 69W by early Thu morning. Then these seas will gradually subside to between 12 and 17 ft but shift to north of 25N between 49W and 64W Thu evening.

Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and https://www.nhc.noaa.gov/marine/offshores.php for more information.

Monsoon Trough/ITCZ

A monsoon trough enters the Atlantic along the Guinea coast near Conakry, then curves southwestward to 04N19W. An ITCZ continues from 04N19W through 03N35W to just north of Belem, Brazil at 0.5N48W. Scattered moderate to isolated strong convection is noted near and north of the ITCZ from 00N to 06N between 43W and the Brazil/French Guiana coast. Widely scattered moderate convection is found south of the monsoon trough from 04N to 06N west of 15W.

Gulf Of America

A surface trough is triggering scattered showers and isolated strong thunderstorms at the central Bay of Campeche. Otherwise, A 1027 mb high at the northeastern Gulf is dominating the rest of the Gulf. Moderate to fresh ENE to E winds and seas of 4 to 7 ft are present at the south-central and southeastern Gulf, including the Straits of Florida. Gentle to moderate ENE to ESE winds and 3 to 5 ft seas are noted at the north-central Gulf. Light to gentle winds with seas at 1 to 3 ft prevail for the rest of the Gulf.

For the forecast, the 1027 mb high will continue to support moderate to fresh NE to E winds and moderate to rough seas across the south-central and southeastern Gulf through tonight. Areas of fog are possible across the northern Gulf into Thu. A ridge will remain in control of the weather pattern across the Gulf region the remainder of the week, with a high pressure center located over the northeastern Gulf Thu through Sat. This system will produce mainly a gentle to moderate wind flow with slight to moderate seas. Looking ahead, the next cold front is expected to enter the northwestern Gulf on Mon, followed by fresh to strong northerly winds and rough seas, except gale conditions will be possible in the far west-central Gulf, and in the northwest part of the southwestern Gulf Mon night.

Caribbean Sea

A robust trade-wind regime continues across much of the Caribbean Sea. Convergent trades are creating scattered showers and isolated thunderstorms at the Gulf of Honduras, and south of Haiti. Fresh to strong NE winds and seas of 5 to 8 ft are evident at the south-central basin, lee of Cuba, near the Windward Passage and near Hispaniola. Gentle to moderate NE winds and 3 to 5 ft seas are seen at the eastern basin. Moderate to fresh NE to E winds and seas at 4 to 6 ft prevail elsewhere in the Caribbean Sea.

For the forecast, strong high pressure across the western Atlantic combined with the Colombian low will continue to support fresh to strong winds in the lee of Cuba, the Windward Passage, and the central Caribbean through Thu night, except through Mon off Colombia. Long-period northerly swell moving into the northeastern passages will gradually subside Thu. This will be followed by additional northerly swell arriving into northeastern passages late Fri into Sat before subsiding Sun.

Atlantic Ocean

See Special Features at the beginning about Gales and Significant Swell.

A strong cold front curves west-southwestward from east of Bermuda across 31N62W to beyond 31N77W. Patchy showers and isolated thunderstorms are occurring near and up to 50 nm north of the front. Convergent SE to SW winds farther east are causing scattered to numerous showers and isolated strong thunderstorms north of 27N between 56W and 63W. At the central Atlantic, a weakening stationary front reaches southwestward from the north- central Atlantic across 31N37W to 23N57W. Scattered moderate convection is occurring up to 150 nm along either side of this boundary. Refer to the Monsoon Trough/ITCZ section for additional convection in the Atlantic Basin.

Outside the area mentioned in the Special Features section, Moderate to fresh W to NW winds and seas of 6 to 10 ft dominate north of 27N between 52W and 72W. Gentle to moderate N to NE winds and 4 to 6 ft seas are present north of 20N and west of 72W. From 20N to 27N between 52W and 72W, gentle to moderate N to NE winds and seas at 7 to 9 ft in large northerly swell exist. Farther east, north of 20N between 35W and 52W, gentle to moderate SE to S winds with 6 to 10 ft seas in large NW swell are noted. For the tropical Atlantic from 06N to 20N between 35W and the Lesser Antilles, gentle to moderate NE to ESE winds and seas of 6 to 8 ft are evident. For the remainder of the Atlantic Basin west of 35W, light to gentle winds and 4 to 6 ft seas in mixed moderate swells prevail.

For the forecast west of 55W, the stationary front will gradually dissipate tonight. The aforementioned strong cold front is anticipated to move across the Atlantic waters east of the Bahamas through early Thu while weakening. Large swell continues to impact the region east of the Bahamas. Strong winds and a new set of large reinforcing swell will follow this front, mainly over the waters east of 70W through Thu. Another cold front will move over the waters between northeastern Florida and Bermuda Fri before moving east of the area Sat. It will be followed by additional reinforcing swell east of 70W. Looking ahead, yet another front will move off northeastern Florida coast Sat, and move east of the region through Mon.

Posted 2 hours ago by NHC Forecaster Chan