000 AXNT20 KNHC 190555 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Mon Apr 19 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... Eastern Caribbean Ashfall Advisory: An Ashfall Advisory is in effect for La Soufriere Volcano on St. Vincent near 13.3N 61.2W. A new eruption occurred earlier today. GOES-16 Geocolor imagery from yesterday at 2100 UTC right before sunset shows that the plume is diffusing over the east Caribbean from 13N-14N between 61W-63W. 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 extends from the coast of West Africa near 12N16W and continues southwestward to 04N23W. The ITCZ continues from 04N23W to 02N30W to 00N40W. Scattered moderate isolated strong convection is from 02S-04N between 08W-14W. Scattered moderate convection is within 150 nm south of the monsoon trough between 17W-21W. GULF OF MEXICO... As of 0300 UTC, a cold front is over northern Florida entering the Gulf out of Tampa Bay, FL, and extends west to 27N86W where the boundary stalls and continues into the western Bay of Campeche. Scattered showers and thunderstorms continue ahead of the front north of 24N and east of 88W. The latest scatterometer pass reveals fresh to strong N-NE winds behind the front, with the strong winds offshore of Veracruz, Mexico. Seas in this region are 6-11 ft. Ahead of the front and within the Florida Straits, winds are E-NE moderate to fresh, while within the Yucatan Channel winds are fresh from the south. Seas ahead of the front and within the far northeast Gulf are 2-4 ft. The fresh to strong winds occurring west of the front along the Mexican coast will diminish overnight. This front will remain nearly stationary into mid week, before reinforcing cool and dry air pushes the front into the far southeast Gulf from mid to late week. CARIBBEAN SEA... An Ashfall Advisory is in effect for La Soufriere volcano on the island of St. Vincent. See the special features section above for details. A middle-level trough over the Yucatan Peninsula supports a surface trough inland, which is generating scattered moderate to isolated strong convection nearly 120 nm off the coast of Belize into the Gulf of Honduras. Otherwise, deep layer dry air is elsewhere as indicated by low level precipitable water and mid-level water vapor imagery, which is favoring fair weather conditions. A pressure gradient between lower pressure over Colombia and a surface high pressure over the central Atlantic extending into the northern Caribbean continues to support fresh to strong winds over the south-central basin with seas to 9 ft and moderate to locally fresh SE winds in the Gulf of Honduras. Moderate trade winds with seas to 7 ft are elsewhere. The ridge N of the area will shift east ahead of a weak front moving through the Gulf allowing trade winds to increase over mainly the south central Caribbean through mid week. Looking ahead, the trade winds will diminish by late week as the high pressure shifts eastward, although fresh to strong winds will persist off Colombia. ATLANTIC OCEAN... A weak frontal boundary will remain nearly stationary off the coast of northeast Florida through the early part of the week, as a ridge extends westward from the central Atlantic through the central Bahamas. Broad gentle to moderate anticyclonic flow extends over the Atlantic north of 20N. South of 20N trades are moderate to fresh. Looking ahead, as the ridge shifts east by Wed, a slightly stronger frontal boundary will move off the southeast U.S. coast by Thu. This front will reach from near Bermuda to the Straits of Florida by Thu night, then start to stall along 25N through Fri night as high pressure builds between northeast Florida and Bermuda. $$ Mora/Ramos