000 AXNT20 KNHC 131717 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue Apr 13 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... Windward Islands Ashfall Advisory: An Ashfall Advisory remains in effect for La Soufriere Volcano that is on the island of St. Vincent near 13.3N 61.2W. The volcano currently is undergoing light emissions from its summit. It is possible that ash that was released earlier may be reaching the surface of the ocean, and low-level visibility may be reduced. Mariners who are transiting the waters under the emitted ash advisory should exercise caution. Mariners who encounter volcanic ash or floating volcanic debris, are urged to report the observation to the National Hurricane Center, by calling 305-229-4424. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through the coastal sections of Guinea near 09N13W to 04N22W, where scatterometer data indicates that it transitions to the ITCZ near 42N22W and to the delta of the Amazon river near 00N49W. Scattered moderate to isolated strong convection is within 00N to 05N between 22W to 34W and scattered showers along the ITCZ between 34W to 49W. Seas range between 4 to 6 ft within 200 nm on either side of both boundaries. GULF OF MEXICO... Broad surface anticyclonic flow covers the Gulf of Mexico. Broken to overcast low clouds are along and inland the Texas coastal plains. Patches of fog, some dense, are over the NW Gulf. Latest ship obs and altimeter data show wave heights ranging between 2 to 4 ft across the basin. For the forecast, weak high pressure has settled in over the area. This high pressure will shift eastward through Wed in response to an approaching cold front. The cold front will move across the northern Gulf Wed night, reach from north-central Florida to southern Texas Thu and become stationary and weaken through Fri night. Mainly moderate northeast to east winds will follow in behind the front. A stronger cold front is expected to move over the NW Gulf late Fri night, and reach from north-central Florida to the west- central Gulf by late Sat. Fresh to strong northeast winds will follow in behind this front. CARIBBEAN SEA... A cold front extends from the western Atlantic across central Cuba into the western Caribbean Sea to 21N84W. The front is weakening with a few showers still lingering near the boundary. Further south, scattered showers are moving across Honduras and Nicaragua east to Hispaniola. Moderate easterly trades prevail with wave heights between 2 to 4 ft across the basin. On the forecast, moderate to fresh SE winds will continue over the far NW Caribbean through the period, except for pulsing strong winds in the Gulf of Honduras. Elsewhere, generally moderate to fresh trade winds will persist through this week. ATLANTIC OCEAN... A cold front is analyzed from near 30N57W to across central Cuba. Broken to overcast multilayered clouds, with scattered moderate convection are noted to the east of the front from 23N to 32N between 47W-60W. Fresh to strong southwest winds are noted ahead of the front with the latest ASCAT pass. Further east, a 1023 mb high pressure centered near 25N33W remains in control across the east with broad anticyclonic flow covering north of 26N. An Ashfall Advisory is in effect for La Soufriere Volcano on the island of St. Vincent near 13.3N 61.2W. Mariners transiting the Tropical N Atlantic waters south of 15N between 43W-55W should be aware of the possibility for the existence of volcanic ash. For the forecast, the cold front will move eastward and pass east of the forecast waters on Wed. A secondary cold front or low pressure trough will cross the northern waters later today through early Wed, with strong winds and building seas expected N of 27N and E of 75W. Yet another cold front will move off the southeastern U.S. coast later this week and over the northern offshore waters Thu night and Fri, then stall north of the Bahamas this weekend. $$ MTorres