Special Feature

Caribbean Gale Warning: A tight pressure gradient between the western Atlantic high pressure ridge north of the basin roughly along 27N-28N and the Colombian low will continue to support pulsing northeast to east winds to gale force over the waters north of Colombia tonight. Otherwise, strong to near-gale force trade winds and rough seas will prevail across the much of the central Caribbean into early Mon before becoming confined to south of 15N. Rough to very rough seas, in the 12 to 14 ft range, will develop during the times of peak winds.

Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

Northern Gulf of America and near Florida (Invest AL91): Satellite images and surface observations indicate that a broad surface low is located over the eastern Gulf of America. Within this area of broad low pressure, a 1015 mb low is analyzed over the eastern Gulf near 27N84.5W. Presently, winds are light. Satellite imagery shows disorganized moderate to isolated strong convection from 26N to 28N between 85W and 88W. Scattered showers and isolated thunderstorms are elsewhere from 23N to 29N east of 90W. This activity may produce gusty winds, frequent lightning and rough seas. Mariners should exercise caution across this area. Gradual development of this system is possible, and it could become a tropical depression while it moves slowly northward or north-northwestward during the next few days. Interests along the Florida Gulf coast, southern Alabama, and southwestern Georgia should monitor the progress of this system as it is expected to bring heavy rain to portions of that region during the next several days. This system has a medium chance for tropical cyclone formation during the next 48 hours. Please refer to the latest TROPICAL WEATHER OUTLOOK issued by the National Hurricane Center at www.hurricanes.gov for more information.

Tropical Waves

An eastern Atlantic tropical wave has its axis along 31W from 03N to 20N moving westward near 15 kt. Isolated showers are near axis from 04N to 10N and from 15N to 20N.

A central Atlantic tropical wave has its axis along 55W south of 18N to inland South America. It is moving westward around 20 kt. Scattered moderate convection is from 07N to 10N between 52W and 58W.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic near 20N16W, and continues southwestward to 16N23W and to 07N42W, where it transitions to the ITCZ to 07N45W and to 07N52W. Scattered moderate convection is south of the trough from 09N to 13N between 19W-24W. A 1012 low is near 12N20W.

Gulf Of America

Please refer to the Special Features section for details on a broad low pressure area over the eastern section of the Gulf that has a medium chance for tropical cyclone formation during the next 48 hours.

Elsewhere, a 1021 mb high center that is located south-southwest of Louisiana continues to basically control the wind regime throughout the basin generally maintaining gentle to moderate winds. Slight to moderate seas pretty much prevail.

For the forecast, the low pressure will slowly move northward or north-northwestward during the next few days bringing heavy rain to the Florida Gulf coast, southern Alabama, and southwestern Georgia. There is a medium chance of tropical formation with this system through the next 48 hours. Elsewhere, weak high pressure will dominate, producing gentle to moderate winds and slight to moderate seas through early next week.

Caribbean Sea

A Gale Warning remains in effect for the south-central Caribbean near the coast of Colombia. Please refer to the Special Features section for more details. Winds are expected to peak to gale force tonight.

The pressure gradient between central Atlantic high pressure and relatively lower pressure to its south is generally sustaining strong to near gale-force trades over the central Caribbean, with the strongest winds of near gale force noted offshore Colombia per latest satellite scatterometer data passes. Latest satellite altimeter data passes indicate rough to very rough seas to 14 ft over these same waters. Meanwhile, the latest satellite scatterometer data passes show mostly fresh trades south of about 18N and east of 82W. Seas are 6 to 8 ft over these waters. Light to gentle trades along with slight to moderate seas are present elsewhere.

Isolated showers and thunderstorms are over the southeastern part of the basin, and also from 10N to 14N west of 82W to inland Nicaragua and northern Costa Rica.

For the forecast, the pressure gradient between the Atlantic high pressure ridge axis oriented along 27N-28N and the Colombian low will support NE winds pulsing to gale-force across the waters N of Colombia early tonight. Otherwise, strong to near-gale force trade winds and rough seas will prevail across the much of the central Caribbean into early Mon, before contracting to south of 15N. East winds will pulse fresh to locally strong each this evening and on Sun evening in the Windward Passage.

Atlantic Ocean

A weak trough is analyzed from near 31N32W to 28N35W. Another weak trough is from 31N37W to 26N40W. Isolated weak showers are seen north of 25N between 30W and 50W. Otherwise, broad high pressure, anchored by a 1025 mb high centered near 29N56W, covers the central Atlantic and reaches westward to near 76W. The related gradient is generally allowing for moderate to fresh trades south of about 25N and west of 46W, and from 15N to 24N east of 35W. Seas are 4 to 6 ft over these waters, except for higher seas of 5 to 7 ft from 08N to 20N between 54W and the Lesser Antilles. Fresh to strong north to northeast winds are north of 20N and east of 20W to along the coast of Africa. Seas are 5 to 7 ft with these winds. Latest satellite scatterometer data passes reveal south to southwest winds of 10 to 15 kt south of the monsoon trough, and east to southeast winds of 10 to 15 kt south of the ITCZ. Seas are mostly 4 to 6 ft over these waters. Moderate or weaker winds along with moderate seas are elsewhere.

For the forecast west of 55W, the western periphery of the Atlantic high pressure will gradually weaken and drift northward through the rest of the weekend as a broad surface trough forms E of 50W. This trough will shift westward and reach 65W by Wed. Moderate to fresh trades will prevail south of 24N, with gentle winds to the north. Pulsing strong winds are expected during the evenings this weekend N of Hispaniola and in the Windward Passage.

Posted 5 hours ago by NHC Forecaster Aguirre