000 AXNT20 KNHC 180600 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Apr 18 2021 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: A cold front has stalled from near Cedar Key, Florida to Veracruz, Mexico near 20N96W. The latest ASCAT pass revealed strong to near gale force northeast winds behind the front north of 23N. Gale force winds are likely ongoing offshore Tampico, Mexico. Seas will build to 8-10 ft in that area before winds and seas begin to diminish Sunday morning. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at the website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of West Africa near 08N13W and continues southwestward to 03N17W. The ITCZ continues from 03N17W to 02N30W to 00N43W. Scattered moderate convection is within 220 nm north of the ITCZ between 20W-29W. GULF OF MEXICO... Please see the Special Features section for details on the Gale Warning in effect for the west-central Gulf of Mexico. A cold front has stalled from near Cedar Key, Florida to Veracruz, Mexico near 20N96W. The boundary continues to support showers and thunderstorms north of 27N. Scattered showers are also moving offshore of Tamaulipas, Mexico. South of the front, mainly W-SW winds are gentle to moderate. A surface trough extending from 23N88W to southern Mexico is supporting NE-N winds on the western side of the Yucatan Peninsula. For the forecast, the front will remain nearly stationary through early week, before reinforcing cool and dry air pushes the front into the far SE Gulf for the middle of the week. CARIBBEAN SEA... La Soufriere volcano on Saint Vincent remains in a continually active state, and additional eruptions and ash plumes are possible at any time. Mariners transiting the nearby waters should exercise caution, and are encouraged to report volcanic ash to the National Hurricane Center by calling 305-229-4424. Shallow moisture over the SW Caribbean, upper-level diffluence and the east Pacific monsoon trough continues to support scattered showers and thunderstorms over the offshore waters of Costa Rica, Panama and SE Nicaragua. Deep layer dry air is elsewhere, thus favoring fair weather conditions. The pressure gradient between higher pressure in the central Atlantic and lower pressure over the Gulf of Mexico is allowing for fresh trade winds over the central Caribbean, including the waters between Jamaica and Cuba and fresh to strong E-SE winds within the Gulf of Honduras with seas to 7 ft. Elsewhere across the basin, winds are moderate to fresh with seas 3- 6 ft. For the forecast, fresh to strong SE winds will persist north of central Honduras into Sun night, between the ridge and lower pressure over the southwest Gulf of Mexico. The night will shift east ahead of a weak front moving through the Gulf allowing trade winds to increase over mainly the south central Caribbean early next week. ATLANTIC OCEAN... A stationary front extends from 33N60W southwestward to Daytona Beach, Florida. Scattered showers and thunderstorms are within 50 nm of the front west of 72W to the coast of Florida. Middle-level diffluence and shallow moisture continues to support scattered showers N of 28N between 50W and 65W. Broad surface ridging is across the remainder Atlantic waters, supporting gentle to moderate anticyclonic flow north of 20N. Moderate to fresh NE to E winds over the West Africa adjacent waters and over the central tropical waters. Otherwise, the remnants of a front are analyzed as a surface trough from 30N36W to 24N56W, which is supporting isolated showers and thunderstorms within 150 nm either side of the trough. Seas range from 6-9 ft. For the forecast, the stationary front roughly along 30N extending to near Saint Augustine, Florida, will remain nearly in place through early week, as high pressure dominates the SE part of the basin. Looking ahead, the ridge will shift east by mid week ahead of a slightly stronger frontal boundary moving off the southeast U.S. coast by late Wed into Thu. $$ Mora/Ramos