000 AXNT20 KNHC 170540 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Apr 17 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 0530 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: As of 0300 UTC, a cold front and an attendant 1008 mb low moved off the Texas coast into the Gulf of Mexico. The front will move southward across the basin bringing strong winds and building seas. An area of gale force northerly winds is expected to develop offshore of the Tampico area Saturday night, behind the front. Seas will build to 12 ft in that area, before winds and seas diminish beginning 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. Eastern Caribbean Ashfall Advisory: An Ashfall Advisory is in effect for La Soufriere Volcano on St. Vincent near 13.3N 61.2W. The latest eruption occurred early yesterday morning around 1000 UTC. GOES-16 Geocolor imagery from yesterday at 2100 UTC shows that the plume is becoming diffuse over the east central Caribbean. The volcano remains in a very 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. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic ocean through the coast of Guinea-Bissau in West Africa near 12N16W and continues southwestward to 04N21W. The ITCZ continues from 04N21W to 02N32W to the coast of Brazil in South America near 00N45W. Scattered moderate isolated strong convection is seen from 03N- 07N between 07W-14W. Scattered moderate convection is noted from 02S-04N between 38W-45W. . GULF OF MEXICO... Please see the Special Features section for details on the Gale Warning in effect for the west-central Gulf of Mexico. As of 0300 UTC, A stationary front extends from 29N83W near Cedar Key, Florida westward to a 1008 mb low located near 29N94W. A cold front extends southwestward from the low to 28N97W near Corpus Christi, Texas. Scattered showers and isolated thunderstorms are located north of 28N across the Gulf. The latest scatterometer data notes south of the front and east of 90W winds are moderate from the S-SW, while west of 90W moderate winds are from the SE-E. Seas are 2-4 ft across the Gulf. The weak stationary front will remain over the northern Gulf into Saturday, before being overtaken by a cold front that will stretch from near Tampa Bay, Florida to central Bay of Campeche by the end of the weekend. Behind the front, gales will develop offshore Tampico, Mexico by Saturday night. CARIBBEAN SEA... An Ashfall Advisory is in effect for La Soufriere volcano on St. Vincent. See the Special Features section above for details. Fresh trade winds prevail over the south-central and eastern Caribbean, with moderate trades in the north central Caribbean. Scatterometer data reveals an area of fresh to strong SE winds offshore of Honduras and Belize, with moderate SE winds elsewhere in the northwest Caribbean. The East Pacific monsoon trough is enhancing scattered moderate convection in the SW Caribbean south of 11N, including over portions of NW Venezuela, N Colombia, Panama, and Costa Rica. Seas of 3-6 ft are over most of the basin, except offshore of Colombia seas are up to 7 ft. For the forecast, fresh to strong SE winds are expected in the NW Caribbean this weekend, and then again Tue night. Fresh to strong trade winds will prevail across the south central Caribbean Sun night through early next week. ATLANTIC OCEAN... A cold front enters the discussion area near 32N67W and extends westward to a 1010 mb low near 31N77W, then continues southwestward to near Daytona Beach, Florida. The latest radar imagery reveals scattered showers and thunderstorms north of 27N off the coast of Florida. Similar convection may be occurring north of 27N between 60W-70W with winds fresh from the SW and seas 6-8 ft. Winds are moderate westerlies W of 70W with seas 3- 5 ft. For the forecast, the front move E but remain N of 28N this weekend. Another cold front will move off the SE U.S. coast Sun. Elsewhere, weak high pressure will dominate. A weak surface trough is over the central Atlantic, stretching from 31N37W to 24N48W to 19N60W. Scattered showers are possible within 60 nm of the trough, south of 26N. Elsewhere, ridging from high pressure dominates supporting gentle to moderate anticyclonic flow north of 20N and west of 35W. Winds south of 20N are mainly fresh to locally strong southeasterlies with seas 6-8 ft. Seas north of 30N range from 7-9 ft. $$ Mora