051 AXNT20 KNHC 101009 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Fri Dec 10 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough remains mostly confined to the African continent, reaching the coast of Guinea near 09N13W and extending to 07N17W. The ITCZ then continues from 07N17W to 01S46W. Scattered moderate convection is noted from 04N to 07N between 16W and 42W. GULF OF MEXICO... A broad surface ridge extends from the Mid-Atlantic states to the Gulf of Mexico. A dry continental airmass continues to suppress the development of showers and thunderstorms across the region, allowing for tranquil weather conditions. Recent scatterometer satellite data and surface observations indicate that moderate to locally fresh SE-S winds prevail W of 90W, while weaker winds are noted elsewhere in the basin. Seas of 2-4 ft are occurring in the Gulf, with the highest seas prevailing in its northwestern waters. For the forecast, the high pressure ridge will gradually shift eastward through Sat afternoon in response to a strong cold front that will move over the NW Gulf on Sat. Moderate to fresh southerly return flow will set-up across the western and central Gulf beginning late Fri ahead of the front. Fresh to strong northerly winds and building seas are expected in the wake of the front through Sat night. The front will weaken as it reaches from central Florida to the SW Gulf Sun and dissipate by 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... The tight pressure gradient as a result of the strong ridge north of the Greater Antilles and lower pressures over northern South America is causing strong to near gale-force trades in the south- central Caribbean, with the strongest winds occurring off the coast of NW Colombia. Fresh to locally strong trades are noted in the north-central Caribbean and moderate to fresh trades elsewhere in the basin. Seas of 5-8 ft are prevalent in the central Caribbean, with the highest seas occurring off NW Colombia. Seas of 2-5 ft prevail in the rest of the basin. Tranquil weather conditions continue across the Caribbean due to very dry atmospheric conditions limiting the formation of convection. For the forecast, the aforementioned pressure gradient between a ridge across the northern Caribbean Sea and the Colombian/Panamanian low will continue to support fresh to strong trades over the south- central Caribbean through the weekend. Moderate to fresh trades will prevail elsewhere. High pressure will continue to strengthen over the western Atlantic today resulting in fresh to locally strong northeast winds in the Windward Passage, the lee of Cuba and south of Hispaniola through Tue night. ATLANTIC OCEAN... A weak stationary front extends from 31N62W to the Space Coast of Florida near 28N80W. A recent scatterometer satellite pass show moderate to locally fresh NE winds behind the frontal boundary. In general, winds W of 60W are moderate or weaker. Seas of 4-7 ft prevail W of 60W. A broad surface trough is located along 51W from 15N to 26N with scattered showers. The rest of the tropical Atlantic is dominated by the robust Azores high, resulting a fairly tranquil weather conditions. Satellite-derived wind data depict fresh to strong easterly winds N of 05N and E of 55W. The strongest winds are confined to E of 33W and N of 16N. Seas of 8-11 ft are found E of 48W, while seas of 5-8 ft are found elsewhere in the basin. For the forecast west of 65W, the weakening stationary front will dissipate through the next 18 hours. High pressure will continue building in the wake of the front, supporting moderate to fresh NE to E winds S of 22N, and mainly gentle to moderate winds N of 22N through Sat night. The next cold front will move off the northeast Florida coast early on 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. 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/. $$ ERA