Special Features

Western Atlantic Significant Swell: Large NW swell generated by a deep low pressure system near Nova Scotia, Canada will maintain very rough seas of 12 to 17 ft from 25N to 31N between 45W and 75W through Wed morning before subsiding below 12 ft on Wed afternoon.

Central and Eastern Atlantic Significant Swell: Large NW to N swell generated by a strong low pressure north of the Azores will continue to causing 12 to 18-ft seas from 22N to 30N between 22W and 48W through Wednesday.

Please read the latest NWS High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at websites: 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 stays mostly over the African Continent. An ITCZ extends west-southwestward from 01N17W through 01N30W to just north of Sao Luis, Brazil near 01S44W. Scattered moderate to isolate strong convection is seen up to 110 nm along either side of the ITCZ west of 27W.

Gulf Of America

A 1026 mb high pressure over the northwestern Gulf continues to dominate the entire Gulf. Gentle NE to SE winds and seas of 4 to 7 ft in moderate NE swell are found across the western and north- central Gulf. Moderate with locally fresh N to NE winds and seas at 5 to 8 ft prevail for the rest of the Gulf, including the Florida Straits. The dry and cold continental airmass moving across the basin sustain widespread stratocumulus clouds south of 26N, while generally clear skies prevail north of 26N. Moisture banking along the eastern flanks of the Sierra Madre Oriental may result in locally heavy rainfall.

For the forecast, residual rough seas in the southeastern Gulf from the earlier frontal passage will subside through the day. Fresh to strong southerly return flow will develop across the northwestern Gulf tonight and expand across the southwestern and central Gulf Wed into Thu, ahead of the next cold front forecast to enter the northwestern Gulf Thu night. This next front is expected to stall from the Florida Big Bend to the central Mexican coastal waters Sat.

Caribbean Sea

The southwestern tail of a cold front extends southwestward from central Hispaniola to northeastern Nicaragua. Scattered showers are occurring up to 80 nm along either side of the front. Moisture banking against the mountainous terrain in Central America may result in locally heavy rainfall across Honduras, Guatemala and Belize. A pre-frontal trough is producing some showers near Puerto Rico. Fresh to strong N to NE winds with seas of 8 to 10 ft are evident behind the front, including the Windward Passage. Fresh with locally strong NE to E winds and 5 to 7 ft seas are noted across the southern Gulf, including waters near the ABC Islands. Gentle to moderate easterly winds and seas at 3 to 5 ft prevail elsewhere in the Caribbean Sea.

For the forecast, the cold front will slide southeastward, reaching north-central Hispaniola to southeast Nicaragua this afternoon, before stalling on Wed from eastern Hispaniola to near the Nicaragua-Costa Rica border. The strong winds and rough seas will gradually diminish and subside tonight through Wed as the front weakens. Broad high pressure will develop across the central and western Atlantic Wed through Sat, and bring a return to fresh to strong trades across the central basin. Meanwhile, rough seas in mixed northerly swell will prevail in the Tropical North Atlantic through the next several days.

Atlantic Ocean

Please see the SPECIAL FEATURES section for information about Significant Swells.

A strong cold front reaches southwestward from well northeast of Bermuda across 31N58W to beyond central Hispaniola. Scattered moderate convection is seen up to 100 nm along either side of the cold front. Convergent trade winds are triggering scattered heavy showers just north of Belem, Brazil. Refer to the Monsoon Trough/ITCZ section for additional convection and weather in the Atlantic west of 35W.

Outside the significant swell area mentioned in the Special Features section, fresh to strong SSW to NW winds and 8 to 11 ft seas are present near the cold front, north of 25N between 50W and the Florida/southern Georgia coast. To the south from 29N to 25N and farther east from 25N to 31N, gentle to moderate ENE to SE winds and 7 to 10 ft seas are evident. For the tropical Atlantic from 03N to 25N and west of 35W, moderate to fresh ENE to SE winds with seas of 7 to 11 ft dominate. For the remainder of the Atlantic west of 35W, gentle to moderate E to SE winds and 6 to 8 ft seas prevail.

For the forecast west of 55W, strong NW winds and rough very rough seas in NW swell will continue behind the front through early afternoon before winds begin to slowly diminish. The front is expected to move slowly southeastward and weaken, reaching from 31N58W to the northern coast of the Dominican Republic this evening, then stall from near 29N55W to the northeastern Dominican Republic Wed, before drifting west and dissipating Thu. High pressure will shift into the Atlantic behind the front tonight through Wed, and develop a broad ridge across the region Thu through Sat. A weak front may move off the southeastern U.S. Coast late in the weekend. Meanwhile, seas will gradually subside through mid-week, lingering to rough over the Atlantic waters farther east of the Lesser Antilles through the end of the period.

Posted 2 hours ago by NHC Forecaster Chan