256 AXNT20 KNHC 112359 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Dec 12 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 1800 UTC surface analysis and satellite imagery through 2350 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: A strong cold front extends from the north-central Gulf SW to Tampico, Mexico this evening. Strong to near gale force N-NE winds are behind the front, except along the NE Mexico adjacent waters where gale force winds are ongoing with seas to 11 ft. These conditions will shift to Veracruz adjacent waters tonight before winds diminish below gale force Sun morning. Please refer to the latest High Seas Forecast product 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 10N15W to 08N21W. The ITCZ continues from 08N21W to 03N33W to 02N50W. Scattered moderate convection is observed from 03N to 11N between 13W and 21W. GULF OF MEXICO... Refer to the section above for details on the Gale Warning in effect for the western Gulf. A strong cold front extends from the north-central Gulf SW to Tampico, Mexico and followed by strong to near gale force winds, except along the NE Mexican adjacent waters where gale force winds are ongoing. Seas are in the 8 to 10 ft, however are forecast to build to 12 ft during the night hours. Light to gentle variable winds are ahead of the front, except in the Yucatan peninsula adjacent waters where an inland surface trough supports moderate to fresh NE to E winds. For the forecast, a high pressure ridge extending from the Atlantic to the central Gulf will continue to shift eastward in response to the strong cold front that is moving across the NW Gulf. The cold front will continue to move E to SE and will weaken as it reaches from central Florida to the SW Gulf Sun, and dissipate on Mon. Fresh to strong east winds will spread westward through the Straits of Florida and to the eastern Gulf S of 26N Mon through Tue night along with building seas. CARIBBEAN SEA... A tight pressure gradient between strong ridging north of the Greater Antilles and lower pressures over northern South America is producing generally fresh to strong trades in the eastern and central Caribbean Sea, including southern Hispaniola and the Windward Passage. Seas of 5-7 ft are ongoing in the central and eastern Caribbean Sea. Gentle to moderate NE to E winds are across the NW basin where recent altimeter data show seas of 3 to 5 ft. For the forecast, the pressure gradient between the ridge across the northern Caribbean and the Colombian/Panamanian low will continue to support fresh to strong easterly trades over the south-central Caribbean through the weekend and early next week. Moderate to fresh trades will prevail elsewhere. High pressure will continue to strengthen over the western Atlantic through the forecast period, resulting in pulsing fresh to locally strong northeast winds and building seas in the Windward Passage, the lee of Cuba and south of Hispaniola through Thu night. ATLANTIC OCEAN... The tail of a weakening cold front extends from 31N50W to 29N54W where a surface trough continues along to 27N64W. High pressure dominates the remainder of the subtropical Atlantic with a strong subtropical ridge centered in the NW Atlantic and a second robust Azores high pressure in the NE Atlantic. As a result of the pressure gradient between the subtropical ridges and lower pressures over NW Africa and the deep tropics, fresh trade winds dominate the waters S of 28N and E of 68W with locally strong winds to the open waters NE of the Leeward Islands and region from 20N to 24N between 30W and 40W. For the forecast west of 65W, high pressure will gradually build across the region producing moderate to fresh NE to E winds S of 22N, and mainly gentle to moderate winds N of 22N through tonight. The next cold front will move off the northeast Florida coast Sun, and reach from near 31N65W to South florida by Sun night. This front is forecast to dissipate over the southeastern waters on Mon. High pressure behind the front will bring fresh to strong northeast to east winds mainly across the waters south of 27N by Mon night. These conditions are expected to last through Tue night. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Low ash concentrations are expected in the vicinity of the volcano with very low concentrations to the southwest. 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/. $$ Ramos