Tropical Waves

A tropical wave is analyzed along 43W, south of 11N, moving westward at 10 to 15 kt. Scattered moderate convection is noted within 90 nm of the ITCZ, on either side of the wave between 40W and 49W.

A tropical wave is moving westward across the central Caribbean, analyzed along 78W-79W, south of 15N and into the Eastern Pacific to near 05N, moving westward 5-10 kt. Widely scattered clusters of moderate convection are around the periphery of the wave, within a few degrees. However, precipitable water products show abundant low-level moisture with this wave converging across the SW Caribbean, from the coasts of Central America to 74W.

Monsoon Trough Itcz

The monsoon trough enters the Atlantic near 13N17W and continues southwestward to 03N25W. The ITCZ extends from 03N25W to 01N34W to 02. 5N41W, then resumes from 04N45W to 07N52W to the coast of Suriname near 06N56W. Scattered moderate to strong convection is observed from 03N to 07. 5N between 12W and 19W. Scattered moderate isolated strong convection is elsewhere within 90 nm of the ITCZ between 20W and 55W.

Gulf Of America

The Atlantic ridge extends west-southwestward across Florida into the central Gulf this afternoon. This pressure pattern supports gentle to moderate SE to S winds across the Gulf basin. Seas are generally 2 to 3 ft except 4 to 5 ft across the coastal waters of Alabama and the Florida Panhandle. Cluster of showers and thunderstorms are near the coast across much of southeast Louisiana and south Texas. Otherwise, skies are fair.

For the forecast, high pressure extending from the western Atlantic across the northern Gulf will change little during the forecast period. The related pressure gradient will generally maintain a gentle to moderate east to southeast wind flow across the basin through the weekend and into early next week, with the exception of fresh to strong winds pulsing off NW Yucatan from the late afternoons and into the night time hours associated with a thermal trough. Scattered to numerous showers and thunderstorms, some possibly strong, are expected to affect portions of the western Gulf through the weekend and into next week. Mariners should keep up with the latest forecasts.

Caribbean Sea

Recent satellite scatterometer data showed fresh to strong trade winds across the central Caribbean, including the Gulf of Venezuela. Seas are 6 to 9 ft with these winds. These winds are the result of the pressure gradient between 1026 mb high pressure SE of Bermuda and lower pressures in northern South America. Moderate to fresh easterly winds and moderate seas are occurring in the eastern Caribbean and Gulf of Honduras. Elsewhere, moderate or weaker winds and slight to moderate seas are prevalent. Late afternoon convection is active across Cuba and Hispaniola, while a clusters of showers and thunderstorms is shifting off the NW coast of Jamaica. Showers and isolated thunderstorms are also about the southwest basin along the monsoon trough. Scattered passing showers are moving into the Leeward Islands and moving across the Virgin Islands.

For the forecast, the pressure gradient between high pressure N of the area and relatively lower pressures in northern South America will support fresh to strong trades over the south- central Caribbean into early next week, creating rough seas over those waters. Fresh to strong trades will also pulse each evening over the Gulf of Honduras. Mostly moderate trades will remain elsewhere through the forecast period.

Atlantic Ocean

A large mid to upper-level low remains NE of the Bahamas between 60W and 70W, and continues to slowly weaken. However, this low continues to support scattered showers across this area between 21N and 28N. The upper low anchors the western end of an Atlantic TUTT originating in a broad upper low near 29N26W. At the surface, a 1026 mb high is centered SE of Bermuda and extends a broad sub- tropical ridge across the Atlantic N of 20N between the Canary Islands and the SE United States. A surface trough, remnants of an old frontal boundary, is analyzed from 28N31W to 24N59W. The Atlantic ridge is forcing fresh to locally strong NE winds and seas of 6 to 9 ft between the W coast of Africa and the Cabo Verde Islands, W of 25W. South of the ridge, and surface trough, moderate to fresh trades and moderate seas of 5 to 7 ft dominate the remainder of the tropical Atlantic, with a few small areas of seas to 8 ft near the strongest winds. Elsewhere N of the trough, a gentle to moderate anticyclonic flow is noted with moderate seas. Little to no convection is occurring outside of that described above. Saharan air can be seen extending from western Africa to near 38W, behind the Atlantic tropical wave.

For the forecast west of 55W, a broad mid to upper-level trough E of the Bahamas will maintain unsettled weather conditions generally to the E and NE of the Bahamas through early Sat afternoon as the trough becomes less defined. Fresh to strong trades will pulse north of Hispaniola during the afternoons and evenings going into early next week. The western part of a backdoor cold front will push south across the eastern portion of the area from Sun afternoon into Mon before stalling near 26N, then begin to weaken and dissipate Tue. Fresh to strong northeast winds along with moderate seas will follow in behind the front, subsiding late Tue. Elsewhere, trades are forecast to increase over most of the western half of the area starting Mon, including the waters between Cuba and the Bahamas as well as the entrance to the Windward Passage as slightly stronger high pressure N of the area shifts east-southeastward leading to a tighter pressure gradient.

Posted 23 minutes ago by NHC Forecaster Stripling