000 AXNT20 KNHC 271707 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Oct 27 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1705 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: Strong to gale force winds will follow a cold front expected to move through the Gulf of Mexico today through Thu night. A gale warning for frequent gusts to gale force has been issued for this area valid from Wed night through Fri. Seas will build as high as 20 ft in the wake of the front over the northern Gulf. Mariners are urged to heed caution as a robust line of showers and thunderstorms will race ahead of the front, producing strong gusty winds, heavy rain and reduced visibility. Please, see the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further details. ...TROPICAL WAVES... The axis of a tropical wave is along 33W, south of 20N, and it is moving W at 10-15 kt. A few showers are noted near the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the southern coast of Senegal near 14N17W to 07N27W and to 07N38W. The ITCZ extends from 07N38W to 08N50W and to NE Venezuelan coast near 10N61W. Scattered moderate convection is observed within 250 nm on both sides on the monsoon trough and ITCZ between 47W and the coast of Africa. Scattered moderate convection is also present within 250 nm of the ITCZ between 57W and 64W. GULF OF MEXICO... The main feature of interest in the Gulf of Mexico is the aforementioned cold front approaching the NW portion of the basin. For more details, please see the Special Features section. As of 1500 UTC, a robust squall line is entering the NW Gulf and an outflow boundary is racing ahead of it. Surface observations indicate that fresh to strong S winds have developed in the NW Gulf ahead of the cold front. Strong wind gusts, heavy rain and reduced visibility can be expected as the squall line races eastward over the N Gulf. Elsewhere, a stationary front extends from SE Louisiana to SW Florida and it is producing a few isolated showers. The rest of the Gulf enjoys fairly tranquil weather conditions. Outside of the influence of the strong cold front nearing the NW Gulf, moderate or weaker winds are found in the remainder of the basin. Seas of 3-5 ft are noted W of 95W and 1-3 ft elsewhere in the Gulf. For the forecast, the previously mentioned cold front will move off the Texas coast today. This front will then move quickly across the Gulf, accompanied by a band of showers and thunderstorms, some strong, through Thu night. Fresh to strong S winds will continue ahead of the front, with strong to gale force winds developing the portions of the north-central and NE Gulf late tonight into Fri. CARIBBEAN SEA... The interaction of a weak surface trough in the central Caribbean Sea and a weak 1010 mb low pressure along the E Pacific monsoon trough results in an area of showers and isolated thunderstorms from the NW coast of Colombia to 14N and between 76W and 79W. The rest of the basin is under the influence of a dry airmass, supporting fairly tranquil weather conditions. A recent scatterometer satellite pass indicate fresh to locally strong trades S of 15N and E of 77W. Fresh trades are also noted in the Gulf of Honduras, while moderate or weaker trades are present elsewhere in the basin. Seas of 4-7 ft are prevalent in the central, SW and E Caribbean, while 2-4 ft are found in the rest of the region. For the forecast, a weak ridge over the northern Caribbean Sea will support mainly fresh trades across the south-central Caribbean, including the Gulf of Venezuela through early Thu. Gentle to moderate SE to S winds will prevail over the NW Caribbean through Thu night ahead of a cold front forecast to reach western Cuba and the NW Caribbean. The front will extend from western Cuba to the Gulf of Honduras by midday Fri, and from central Cuba to NE Honduras on Sat, then stall on Sun from eastern Cuba to near Cabo Gracias a Dios, Nicaragua while dissipating. ATLANTIC OCEAN... A cold front extends from the strong extratropical cyclone off New England, entering the tropical Atlantic near 31N66W to 27N71W, becoming a stationary front and continuing across the NW Bahamas and South Florida. There is a pre-frontal trough that extends from 31N63W to the central Bahamas. Scattered showers to isolated thunderstorms are found N of 25N and between 61W to 75W. Recent scatterometer satellite data show fresh to strong cyclonic winds N of 25N and between 57W and 75W. Seas of 7-10 ft are occurring N of 28N and between 60W and 77W. Elsewhere, a couple of weak troughs are found in the central Atlantic, but no significant convection is associated with these features. The central and eastern tropical Atlantic are dominated by a broad 1023 mb high pressure between the Azores and Madeira Islands, supporting fairly tranquil weather conditions and moderate to locally fresh winds. Seas 4-7 ft are noted across most areas in the basin. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Marine and aviation interests should monitor this ongoing situation by reading the Volcanic Ash Advisory issued by Meteo-France, at http://vaac.meteo.fr/volcanoes/la- palma/. For the forecast west of 65W, a cold front from near Bermuda to around West Palm Beach, Florida, is beginning to stall, and will dissipate tonight. and early Thu. N of 25N and E of 75W, fresh to strong W winds follow this boundary, along with seas of 8 to 10 ft. The next cold front from will sweep through Thu night through Fri night, then stall from 31N68W to eastern Cuba over the weekend. Fresh to strong winds and building seas are expected on either side of this front. $$ DELGADO