000 AXNT20 KNHC 070951 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue Dec 7 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 0945 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough is over the African continent. The ITCZ extends from the coast of Sierra Leone near 08N13W to 04N30W to the coast of Brazil near 02N50W. Scattered moderate isolated strong convection is noted from 02N-06N between 25W-35W. GULF OF MEXICO... A ridge extends across Florida into the eastern Gulf of Mexico where a 1018 mb high pressure is located near 26N86W. A stationary front stretches from the Florida Panhandle to near Brownsville, Texas. Moderate to fresh N to NE winds follow the front. Light to gentle winds are noted elsewhere across the Gulf region per satellite derived wind data. Seas are 4-6 ft over the NW Gulf and W of the front while seas of 1-3 ft dominate the remainder of the basin. Some cloudiness, with possible showers, in association with the frontal boundary, is observed from southern Texas all the way to SE Georgia and the Carolinas. A dense fog advisory is in effect across the coastal waters of western Florida from near Ft. Myers to the Florida Big Bend through mid-morning. Visibility will frequently be reduced to less than one quarter mile or less. For the forecast, the aforementioned stationary front extending from the Florida Panhandle to near Brownsville, Texas will retreat inland by tonight. A ridge will build westward across the basin, with a high pressure cell remaining over the eastern Gulf. Moderate to fresh southerly return flow will set-up across the western and central Gulf on Fri and Sat, ahead of a strong cold front forecast to push off the Texas coast by Sat morning. Increasing winds and building seas are expected in the wake of the front. Looking ahead, gale conditions are possible behind the front during the upcoming weekend. CARIBBEAN SEA... The most recent scatterometer data provide observations of fresh to strong winds over the south-central Caribbean, and in the Gulf of Venezuela, where several wind barbs of 25-30 kt are noted. Moderate to fresh trade winds prevail across the remainder of the E and central Caribbean, particularly from 11N-18N and E of 80W. Elsewhere, gentle to moderate winds are blowing. Seas in the 8-10 ft range are over the central Caribbean, with the highest seas near the coast of Colombia. Seas of 6-8 ft dominate the remainder of the east and central Caribbean. Seas of 4-6 ft can be found in the NW Caribbean, except in the lee of Cuba, and the Yucatan Channel. Shallow moisture embedded in the trade wind flow will continue to move across the region producing isolated to scattered passing showers. For the forecast, high pressure located north of the Caribbean Sea combined with the Colombian low will support fresh to strong trade winds over the south-central Caribbean and in the Gulf of Venezuela through the week. Moderate to fresh trades will prevail elsewhere except in the NW Caribbean where mainly gentle to moderate winds are expected. By Thu night into Fri, as high pressure strengthens over the western Atlantic, expect fresh to locally strong NE winds in the Windward Passage, and in the lee of Cuba. This will persist through Sat while extending eastward toward Hispaniola and Puerto Rico. ATLANTIC OCEAN... A surface ridge extends from Bermuda to the Bahamas. Gentle to moderate winds are noted under the influence of this system with the exception of moderate to fresh winds just N of Hispaniola. Seas are in the 5-7 ft range E of the Bahamas based on buoy observations and an altimeter pass. Seas of 3-5 ft prevail elsewhere N of 27N. An area of showers and thunderstorms extends from the NW Bahamas to near 31N73W. A diffluent pattern aloft supports this convective activity. For the forecast west of 65W, a ridge will prevail along 26N-27N through late this week. Moderate to fresh NE to E winds are expected along the southern periphery of the ridge, especially south of 22N, including the waters just N of Hispaniola and approaches to the Windward Passage. A weak cold front will stall over the far northern waters today, then lift northward by tonight. Another cold front will move over the northern forecast waters Thu and Fri while dissipating. The remainder of the Atlantic forecast waters is under the influence of a 1036 mb high pressure located well N of area near 42N43W. A surface trough is along 55W/56W from 21N-30N. Isolated showers are near the trough axis. An upper-level low spinning W of the Canary Islands is generating some shower activity over the islands and regional waters. Fresh to located strong trade winds and seas of 8-10 ft are observed over the Atlantic, mainly N of 10N and E of 50W due to the pressure gradient between the strong high pressure to the N and lower pressures in the vicinity of the ITCZ. 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/. The latest advisory states that low ash concentration is expected W of the volcano. $$ GR