Tropical Waves

An eastern Atlantic tropical wave is near 34W from 11N southward, and moving westward around 15 kt. Scattered showers and isolated thunderstorms are seen from 01N to 03N between 32W and 36W.

An eastern Caribbean tropical wave is near 66W from 14N southward across Venezuela, and moving westward at 15 to 20 kt. Scattered moderate to strong convection is evident over northern Venezuela.

Monsoon Trough Itcz

A monsoon trough enters the Atlantic along the Mauritania coast near Nouakchott, then curves southwestward to 06N22W. An ITCZ continues from 06N22W to 03N32W, then resumes from 02N36W to near the Amazon River Delta. Scattered moderate to isolated strong convection is occurring near and south of the monsoon trough from 05N to 10N west of 20W. Widely scattered moderate convection is present up to 80 nm along either side of both ITCZ segments.

Gulf Of America

A modest surface ridge runs southwestward from northern Florida to the central Gulf. Southerly flow associated with this feature is advecting abundant tropical moisture across the central and eastern Gulf. Meanwhile at the upper level, a pronounced trough is quasi-stationary across the western Gulf. Divergent winds east of this upper trough is coupling with the moisture to trigger scattered heavy showers and isolated strong thunderstorms over the central and northeastern Gulf, including the central Bay of Campeche. Isolated thunderstorms are also found at the east- central and southeastern Gulf. Gentle to moderate E to SE winds and 2 to 4 ft seas dominate the entire Gulf, except locally gusty winds and rough seas near heavy showers and thunderstorms.

For the forecast, the aforementioned surface ridge will sustain gentle to moderate with locally fresh E to SE winds through Thu. The exception will be fresh to strong winds off northwestern Yucatan, and at the northwestern Gulf on Wed night. Scattered heavy showers and strong thunderstorms over the central and northeastern Gulf will persist through at least Wed morning. These thunderstorms are capable of producing gusty winds, frequent lightning, limited visibility and locally rough seas. Mariners are urged to keep up to date with the latest forecast.

Caribbean Sea

Convergent trade winds are triggering scattered showers and isolated thunderstorms from southwestern Cuba across the lee of Cuba to over southeastern Hispaniola. Otherwise, a robust trade-wind regime continues with strong to near-gale ENE to E trades and 9 to 11 ft seas at the south-central basin. Fresh to strong E winds and seas of 6 to 8 ft dominate the north-central and northeastern basin. Moderate to fresh ENE to E winds and seas at 4 to 6 ft are noted at the southeastern and part of the southwestern basin. Fresh E winds with 4 to 6 ft seas are evident at the Gulf of Honduras. Gentle to moderate NE to ESE winds and seas of 3 to 5 ft prevail for the rest of the Caribbean Sea.

For the forecast, tight pressure gradient between high pressure in the western Atlantic and the Colombian low will continue to support fresh to strong trades over the south-central Caribbean with rough seas through Thu. These winds are expected to pulse to near-gale force off Barranquilla, Colombia during night-time and morning hours through Wed night. In addition, moderate trades in the Gulf of Honduras will reach fresh to strong each evening through the same period. Fresh to strong trades and rough seas are going to expand northward into the north-central basin by this afternoon, then gradually subside on Thu.

Atlantic Ocean

A cold front curves southwestward from near the Azores across 31N42W to 27N53W, then turn northwestward to beyond 31N61W. Scattered showers are occurring up to 100 nm along either side of this boundary. Aided by modest divergent flow aloft, convergent trades are generating scattered showers and isolated thunderstorms near the Lesser Antilles. Refer to the Monsoon Trough/ITCZ section for additional convection in the Atlantic Basin.

Fresh to strong NE winds and 7 to 9 ft seas are present near and behind the aforementioned cold front. Fresh to strong E winds are noted from 20N to 25N and west of 55W, including the Great Bahama Bank. In this area, seas range from 6 to 9 ft east of 76W, and 3 to 6 ft west of 76W. North of 25N and west of 55W, moderate to locally fresh E to SE winds along with 4 t 6 ft seas are present, including the central and northwest Bahamas. To the east, a broad Atlantic Ridge is supporting light to gentle winds and seas at 3 to 5 ft north of 20N between 35W and the cold front. For the tropical Atlantic from 05N to 20N between 35W and the Lesser Antilles, moderate to fresh NE to E winds and 6 to 8 ft seas are seen. For the remainder of the Atlantic Basin west of 35W, gentle to moderate E to SE winds and seas at 4 to 6 ft in mixed moderate swells prevail.

For the forecast west of 55W, fresh to strong winds with moderate to rough seas are anticipated across waters south of 25N through Wed morning, including the Great Bahama Bank as a strong Atlantic high pressure begins to shift southeastward tightening the pressure gradient. As the high begins to weaken Wed, it should allow winds and seas to diminish from east to west. Moderate to fresh trades north of Hispaniola will pulse to strong at night through Wed night, creating moderate to rough seas. The western part of a cold front near 29N57W will push farther south to near 25N56W by tonight before gradually dissipating on Tue. Fresh to strong NE winds along with moderate to rough seas will follow the front, then slowly subside on Tue.

Chan Posted about 5 hours ago by NHC Forecaster