Based on 1200 UTC surface analysis and satellite imagery through 1615 UTC.

, SPECIAL FEATURES, Corrected

Central Atlantic Significant Swell Event: Gale-force winds have diminished over the waters north of 30N between 47W and 56W. The long duration of these winds has resulted in very rough seas that have spread southeastward over a large portion of the central Atlantic. Both altimeter satellite data passes and Sofar Spotter buoy data indicate seas of 18 to 24 ft (5.5 to 7 m) in west to northwest swell at 14 to 16 seconds north of about 27N between 46W and 55W. Seas of 12 to 18 ft (2.5 m to 5.5 m) are present elsewhere north of 21N and between 38W and 66W. The swell will slowly decay from W to E allowing for these seas to drop below 12 ft (4 m) for most areas by early Wed evening. Mariners are urged to stay up to date with the latest forecasts.

South-Central Caribbean Gale Warning: A tightening pressure gradient between building high pressure over the western Atlantic and relatively lower pressure in Colombia and Panama will lead to fresh to strong winds across most of the central Caribbean, including the Windward Passage, and the waters between Cuba and Jamaica into Wed night. Winds will pulse to minimal gale-force tonight and again on Wed night offshore Colombia. Seas with these winds are expected to be in the 8 to 11 ft (2.5 to 3.5 M) range.

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 details on these events.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic through the extreme southeast coast of Liberia near 05N08W to 02N13W and to 01N22W, where it transitions to the ITCZ to 01N30W, to south of the Equator at 42W and to along the coast of Brazil near 01S47W. Scattered moderate convection extends from 00N to 06N between 08W and 33W and from 00N to 04N between 37W and 42W.

Gulf Of America

A surface ridge extends across the Gulf, anchored by a 1026 mb high pressure that is centered northeast of the Bahamas near 28N74W. The pressure gradient between the ridge and relatively lower pressure in the far western Gulf is generally allowing for gentle to moderate mostly southerly flow across the basin, with the exception of moderate to locally fresh south winds offshore NE Mexico and southern Texas. Both latest buoy and altimeter satellite data passes indicate seas of about 2 to 4 ft throughout, except for lower seas of 1 to 2 ft in the NE Gulf.

For the forecast, high pressure will generally dominate Gulf waters through late week, bringing a gentle to moderate mainly southerly flow. Locally fresh winds are expected today and tonight just west of the Yucatan Peninsula and over the far western waters. Slight to moderate seas will prevail. Looking ahead, southerly winds may increase this weekend ahead of an approaching cold front, forecast to move across the western Gulf on Sun.

Caribbean Sea

See Special Features section above for details on a Gale Warning in effect for the offshore waters of Colombia.

High pressure N of the area is building southeastward toward the Caribbean, which is increasing northeast winds over much of the basin to fresh to strong speeds. Seas are mostly 5 to 7 ft, although rough seas are occurring in the southwestern basin offshore Colombia, south of Hispaniola, and through the Atlantic passages from the Mona Passage eastward as noted in recent altimeter satellite data passes.

For the forecast, aside from the Special Features forecast for gale-winds offshore Colombia tonight and Wed night, the same inducing pressure gradient of those winds will also lead to fresh to strong northeast to east winds over most of the central Caribbean, including the Windward Passage, and the waters between Cuba and Jamaica into Wed night. In addition, large northwest to north swell will impact the Mona Passage, Anegada Passage, and tropical N Atlantic waters into Wed creating hazardous marine conditions.

Atlantic Ocean

Please see the Special Features section for details on an ongoing central Atlantic significant swell event.

Hazardous marine conditions from very rough seas dominate most of the central subtropical basin as described above in the Special Features section.

A cold front has recently entered the northern portion of central Atlantic along a line from near 31N45W to 26N57W. Latest scatterometer satellite data shows fresh to strong west to northwest winds behind the front to near 63W and north of 27N, and moderate to fresh northwest to north winds elsewhere west of the front to near 72W. Fresh to strong south to southwest winds are ahead of the front north of 26N, east to a line from 31N35W to 26N39W. Seas behind the front outside the significant swell event seas are in the range of 8 to 12 ft (2.5 to 4 m) in northwest to north swell elsewhere from 09N to 21N between 38W and 62W and from along the Leeward Islands, Puerto Rico and the central and southeastern Bahamas north-northeast from 21N to 24N. Otherwise, a stationary front is dissipating from near 31N39W to 25N50W to the Virgin Islands and to the eastern Caribbean near 15N70W. Scattered to broken low clouds, with possible isolated showers are noted from 17N to 21N between 60W and 65W. Similar clouds, also with possible isolated showers, are seen from 15N to 17N between 58W and the Leeward Islands to the northern Windward Islands. Northeast winds of fresh speeds are over the waters roughly from 15N to 20N between 59W and 62W. Moderate to fresh trades are east of 59W, southeast of a line from the Canary Islands to the Windward Islands. Seas are 5 to 7 ft over these waters, except for slightly higher seas of 7 to 9 ft in northwest swell north of 18N east of 28W, and of 6 to 8 ft in northwest south of 09N between 41W and 55W. Light to gentle mostly southeast to south winds are over an area bounded from 16N to 22N between 35W and 54W. This is near and along a ridge axis that stretches southwestward from a 1027 mb high that is analyzed in the far eastern Atlantic at 30N21W and where similar winds are found.

For the forecast west of 55W, near gale-force winds over the far northeast part of the area will gradually diminish into tonight as high pressure moves eastward across the waters. On the west side of the high, southwesterly winds will increase over the NW waters starting tonight, then reach strong speeds Wed, with seas building to rough N of 28N. These winds will prevail over northern waters through Wed night, before becoming strong northwest winds as a cold front crosses the waters into Thu. Very rough seas in northwest to north swell east of 67W will gradually decay below 12 ft from W to E today and tonight, with improved seas by Wed.

Posted 2 hours ago by NHC Forecaster Aguirre