000 AXNT20 KNHC 110551 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu Nov 11 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 0000 UTC surface analysis and satellite imagery through 0550 UTC. ...SPECIAL FEATURES... A storm-force non-tropical low pressure center is about 900 miles to the ENE of Bermuda. Rainshowers extend from the center northward along an associated frontal boundary. This system is moving northeastward. It is possible that it still may become a short-lived subtropical storm, before it reaches cooler waters by this evening. The system is expected to be absorbed by a larger non-tropical low pressure center, by this weekend. Additional information about this system, including hurricane-force wind warnings, is in High Seas forecasts that are issued by the National Weather Service. The formation chance through 48 hours is medium. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Guinea near 09N13W, to 09N15W. The ITCZ continues from 09N15W, to 07N20W, 04N30W, 05N32W, and 04N43W. Precipitation: scattered moderate to widely scattered strong is within 300 nm of the coast of Africa from 03N to 10N. Isolated moderate to locally strong is from 10N southward between 20W and 28W. Isolated moderate is elsewhere from 10N southward from 60W eastward. GULF OF MEXICO... Broad surface anticyclonic wind flow spans the Gulf of Mexico. A surface ridge extends from the northeastern corner of the area, to the southwestern corner of the Gulf of Mexico. Moderate anticyclonic winds cover the Gulf of Mexico. The sea heights range from 1 foot to 3 feet. Gentle to moderate return flow will prevail through tonight, locally fresh in the western Gulf of Mexico. A cold front will move into the northern Gulf coastal waters Thu, stalling Thu night into Fri. Reinforcing high pressure will push the front across the Gulf Fri night through Sat night, moving southeast of the basin early Sun. High pressure will build in the wake of the front, with winds in the southeast Gulf increasing to fresh to strong early next week. CARIBBEAN SEA... A shear line curves toward the southwest, to 16N82W, to the coastal waters of SE Nicaragua. Fresh to strong winds are within 240 nm to the northwest of the shear line between 79W and 84W. Precipitation: isolated moderate to locally strong is to the northwest of the shear line, and from 80W westward. Upper level cyclonic wind flow remains in the NW corner of the Caribbean Sea. An east-to-west oriented surface trough is in the Gulf of Honduras. The monsoon trough is along 07N/10N, from northern Colombia at 74W beyond parts of southern Panama. Precipitation: no significant deep convective precipitation is apparent only with the monsoon trough. Comparatively drier air in subsidence is apparent in water vapor imagery, from 75W eastward. Upper level anticyclonic wind flow covers the same area as the area of subsidence. Fresh to strong NE winds are from 16N southward between 65W and 78W from the Greater Antilles southward. Gentle to moderate winds are elsewhere. The sea heights range from 3 feet to 5 feet. The tail end of a stalling front, that extends from near the Windward Passage to Jamaica and continuing to offshore of Nicaragua, gradually will dissipate through the end of the week. Moderate to fresh winds in the NW Caribbean Sea will diminish to gentle by the end of the week. Moderate to fresh winds will prevail across the remainder of the basin, pulsing to fresh to strong in the south central Caribbean Sea tonight and again on Thu night. A new cold front is forecast to move into the NW Caribbean Sea by the end of the upcoming weekend. ATLANTIC OCEAN... A cold front passes through 31N50W, to 25N60W, to 22N66W. The cold front is dissipating from 22N66W to the Windward Passage. A shear line curves toward the southwest, to 16N82W, to the coastal waters of SE Nicaragua. Precipitation: isolated moderate to locally strong is within 120 nm to the east of the cold front from 27N northward. Rainshowers are possible elsewhere from 20N northward from 50W westward. Upper level cyclonic wind flow, with a trough, covers the waters that are from 16N northward from 34W eastward. A surface trough is along 31W/33W from 20N to 32N. Precipitation: isolated moderate to locally strong is from 20N northward from 38W eastward. A 1018 mb high pressure center is near 29N40W. A 1023 mb high pressure center is near 33N76W. Moderate to fresh winds are from 270 nm to 760 nm to the south of the high pressure center, from Cuba and Hispaniola to 29N from 67W westward. The sea heights from the Bahamas southward range from 2 feet to 5 feet. The sea heights range from 8 feet to 10 feet, from 20N northward from 68W westward, and from the Bahamas northward. This area is the area that is to the west and the northwest of the cold front. Broad surface anticyclonic wind flow covers the Atlantic Ocean from the cold front westward and northwestward, from 60W westward. Fresh to strong winds, and faster, are from 28N northward between 43W and 64W. Fresh to strong NE winds are within 90 nm to 180 nm on either side of the line that runs from the northern coast of Senegal, to 12N21W to 09N31W. Gentle to moderate winds are elsewhere. The sea heights range from 8 feet to 10 feet, from 20N northward from 68W westward, and from the Bahamas northward. The sea heights range from 4 feet to 6 feet, elsewhere, from 50W eastward, and from 20N southward between 50W and 60W. 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 tail end of a cold front extending from 23N65W to the Windward Passage will continue moving southeast through Thu, stalling and dissipating along 22N by Fri. Large seas following the front will gradually decay through the end of the week. The western remnants of the front in the form of a trough will linger between 70W and 77W into the early part of the weekend, with weak low pressure possibly developing along it before moving north of the area late Sat. The next cold front will move off NE Florida by Fri night, then stall. Reinforcing high pressure will slowly push the front across the region during the weekend into early next week. $$ mt/torres