Tropical Waves

An eastern Atlantic tropical wave has its axis near 25W, south of 18N to near the Cabo Verde Islands, moving westward at around 5-10 kt. Any nearby convection is discussed in the ITCZ/MONSOON TROUGH section below.

Another Atlantic tropical wave has its axis near 45W, south of 18N, moving westward at around 10 kt. Any nearby convection is discussed in the ITCZ/MONSOON TROUGH section below.

An eastern Caribbean tropical wave has its axis near 64W, south of 18N near the Anegada Passage to eastern Venezuela, moving westward at around 10 kt. Any nearby convection is discussed in the ITCZ/MONSOON TROUGH section below.

A western Caribbean tropical wave has its axis near 85W, south of 19N across portions of eastern Honduras and central Nicaragua, moving westward at around 10 kt. Any nearby convection is discussed in the ITCZ/MONSOON TROUGH section below.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic off the coast of Africa near 14N17W and extends SW to near 06.5N29W. The ITCZ extends from 06.5N29W to 06N43W where it becomes ill-defined due to a tropical wave to the west. Isolated to widely scattered moderate and isolated strong convection is noted from 01N to 09N between 10W and 55W.

Gulf Of America

A ridge extends from subtropical high centered in the Atlantic to across Florida and the Gulf along 26N, with a surface trough extending from eastern Mexico, across the SW Gulf. The pressure gradient between these features is supporting fresh to strong winds across much of the Gulf. Seas are in the 4-7 ft over much of the Gulf, reaching 8 ft off the coast of Louisiana to the western Florida Panhandle.

For the forecast, the Atlantic ridge extends across Florida into the Gulf region. The pressure gradient between this system and lower pressures over Texas and northeastern Mexico will support fresh to strong southerly winds over the western and central Gulf, and moderate to fresh winds over the eastern Gulf through Fri. Expect rough seas N of 27N and offshore of the Louisiana coast this afternoon to shift eastward with these winds through tonight before diminishing. Winds and seas will diminish basin-wide late Fri through the weekend as weak high pressure settles over the eastern Gulf.

Caribbean Sea

The broad subtropical ridge over the western Atlantic extends westward along 27N-28N and across central Florida. The pressure gradient between the ridge and the Colombian low is supporting fresh to strong winds over the central Caribbean, where seas are in the 6-8 ft range. Fresh to locally strong winds are over the Gulf of Honduras as well as in the eastern Caribbean. Gentle to moderate winds, and seas of 4-6 ft, are across the remainder of the Caribbean. A large cluster of deep convection is noted south of 14N between 74W and 82W with locally higher winds and seas possible there.

For the forecast, the Atlantic ridge will remain in place north of the area through early next week, while weakening slightly Fri night through Sun, as a frontal system clips the waters off NE Florida. The pressure gradient south of the ridge will sustain fresh to strong trade winds and moderate to rough seas in the central Caribbean through the forecast period, with highest winds and seas expected off the coast of Colombia. Pulsing winds at fresh to strong speeds and moderate to rough seas are expected in the Gulf of Honduras nightly through Mon, pulsing briefly to near gale- force tonight and Fri night. Moderate to fresh E to SE winds are expected elsewhere across the northwestern Caribbean through Mon night. Active showers and thunderstorms are expected across SW portions through Sat as an upper-level trough digs into the area.

Atlantic Ocean

A frontal trough extends from 31N33W to 25N44W. Isolated moderate convection is in the vicinity of the trough. The rest of the discussion waters N of 20N is dominated by high pressure anchored by a 1024 mb subtropical high centered near 28N57W. Light to gentle winds are in the vicinity of ridging extending from 31N22W to the high to central Florida. Moderate to locally fresh winds dominate the remainder of the discussion waters, except fresh to strong N-NE winds from 18N to 24N between Africa and 21W. Seas are in the 3-6 ft range, except locally to 7 ft south of 22N.

For the forecast west of 55W, the Atlantic ridge will remain in place through early next week, while weakening slightly Fri night through Sun, as a frontal system clips the waters offshore of NE Florida. The front is forecast to move slowly offshore on Sat, and stall offshore NE Florida by Sun. Fresh to locally strong SW winds are expected N of 30N and ahead of the front tonight through Fri. Moderate to fresh trade winds are expected south of 22N, around the southern periphery of the ridge, through Sun. These winds will likely increase to strong speeds Sun night through Mon night.

Posted 0 minutes ago by NHC Forecaster Lewitsky