Special Features

Caribbean Gale Warning: A tight pressure gradient between the subtropical ridge north of the islands and lower pressures in NW South America will support strong to near gale-force winds and rough seas in the central Caribbean during the next several days. Winds will increase to gale-force in the offshore waters of Colombia and in the Gulf of Venezuela tonight. Seas are expected to build to around 13 ft with these winds. Please read the latest High Seas Forecast issued by the National Hurricane Center at website - https://www.nhc.gov/text/MIAHFSAT2.shtml

Tropical Waves

An eastern to central Atlantic tropical wave is along 36W, south of 20N, moving quickly westward at 20 to 25 kt. Scattered moderate to isolated strong convection is present from 04N to 07N between 25W and 30.5W.

A tropical N Atlantic tropical wave is along 57W, south of 19N to near Barbados and Suriname, moving quickly westward at around 20 to 25 kt. Nearby convection which is present is described below with the ITCZ.

An western Caribbean tropical wave is along 79W, south of 20N just to the west of Jamaica, moving quickly westward at around 25 kt. Any nearby convection is currently observed in the far eastern Tropical Pacific.

Monsoon Trough/ITCZ

The monsoon trough reaches the Atlantic from the northern coast of Mauritania at 20N16W to southeast of the Cabo Verde Islands to 09N28W to 12N40W. The ITCZ extends from 12N40W to 10N56W, then resumes west of a tropical wave from 10N58W to the far NE coast of Venezuela at 08N62W. Scattered moderate isolated strong convection is noted within 210 nm NNW of the ITCZ between 48W and 59W.

Gulf Of America

High pressure of 1018 mb is remaining over the central Gulf near 25N88W with a northwest to southeast ridge through the high. As a result, anticyclonic winds are light to gentle along and around the ridge axis, and moderate along the periphery closer to the Gulf coastlines. Seas are 1 to 2 ft near the weaker winds, and 2 to 4 ft elsewhere. Some moderate convection is noted near the NW coast of Yucatan near a surface trough analyzed over the peninsula, with additional activity near the coast of Florida, Mississippi and Alabama.

For the forecast, a surface ridge will remain in control of the weather pattern across the Gulf region promoting gentle to moderate winds for the next several days. The exception will be fresh NE winds off the northwest coast of the Yucatan peninsula nightly into the weekend. Unsettled weather in the form of scattered showers and thunderstorms will continue over the NE Gulf through the weekend as a frontal boundary remains just N of the area, and at the same a very moist and unstable airmass prevails over region.

Caribbean Sea

Please see the Special Features section above for details on the Gale Warning in effect for the south-central Caribbean.

High pressure north of the islands forces fresh to near gale- force easterly trade winds and rough seas across the central Caribbean, with the strongest winds and highest seas to 11 ft occurring off NW Colombia. Moderate to fresh easterly breezes and moderate seas are found elsewhere from 11N to 18N. Across the remainder of the basin, moderate or weaker winds and slight to locally moderate seas prevail. Some convection is present near eastern Honduras and Nicaragua due to the proximity of a tropical wave and lower to mid level support.

For the forecast, a Gale Warning is in effect tonight for the offshore waters of Colombia and for the Gulf of Venezuela. Seas are expected to build to around 14 ft with these winds. Elsewhere across the central Caribbean, fresh to near gale trades will continue to expand in coverage through early Fri as the pressure gradient between the Atlantic high pressure and low pressure in northern Colombian tightens. Mostly fresh trades will continue elsewhere south S of about 18N through the rest of the forecast period. Fresh to strong winds will pulse in the Gulf of Honduras tonight and Fri night, then to fresh speeds for the remainder of the period.

Atlantic Ocean

A frontal boundary is just north of the discussion waters and SW N Atlantic offshore waters zones from northwest of Bermuda to 1011 mb low pressure near 32N79.5W to near Savannah, Georgia. Associated scattered moderate isolated strong convection is north of 27N and west of 69W. Fresh to strong SW winds and 5 to 9 ft seas are there as well. Otherwise, a broad subtropical ridge continues to dominate much of the tropical Atlantic waters anchored by a 1025 mb high pressure center near 31N51W. Moderate to locally fresh trades are noted north of the monsoon trough and ITCZ to 20N, except fresh to strong N to NE winds from offshore Africa to the Cabo Verde Islands. Seas are 6 to 9 ft across the area of fresh to strong winds, as well as in the Tropical N Atlantic offshore waters zones due to the proximity of a tropical wave. Moderate or weaker winds and moderate seas dominate the remainder of the tropical Atlantic waters.

For the forecast west of 55W, a high pressure ridge extending from near 25N65W to the Straits of Florida will change little through Sat night before it shifts northward to near 28N into early next week. The gradient between the ridge and a frontal boundary just NW of the forecast waters will continue to generally support fresh to strong SW winds along with scattered showers and thunderstorms primarily north of 27N and west of 65W for the rest of the week and into the weekend. Fresh to strong trades will pulse just north of Hispaniola at night and into the mornings through the upcoming weekend.

Posted 0 minutes ago by NHC Forecaster Lewitsky