000 AXNT20 KNHC 091001 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Dec 9 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. ...SPECIAL FEATURES... East Atlantic Gale Warning: A strong high pressure of 1036 mb persists over the Azores. This system is producing a tight pressure gradient off the coast of Morocco, generating N-NE gales in the marine zone of Agadir and the northern part of Tarfaya. These conditions are forecast to continue through 10/0300 UTC. Expect seas of 10-13 ft within the area of gale force winds. Please read the latest High Seas Forecast issued by Meteo France at website http://weather.gmdss.org/II.html for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough remains inland in Africa. The ITCZ extends from the coastal plains of Liberia near 06N10W to 04N30W to the coast of Brazil near 02N50W. Scattered moderate to isolated strong convection is noted from 03N-08N between 24W-44W. GULF OF MEXICO... A weak cold front extends from central Florida to 27N89W where it transitions to a stationary front to 27N93W. Mainly low level clouds, with possible showers, are associated with the frontal boundary. Gentle to moderate E winds are noted behind the front per scatterometer data. There is also an area of moderate E winds just N of the Yucatan Peninsula. Light to gentle winds dominate the remainder of the Gulf. Sea heights are generally below 3 ft except just W of the Yucatan Peninsula and in the Yucatan Channel. For the forecast, the aforementioned cold front will dissipate today. 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 the next cold front forecast to enter the NW Gulf by Sat morning. Fresh to strong northerly winds and building seas are expected in the wake of the front through Sat night. CARIBBEAN SEA... Satellite derived wind data provide observations of fresh to strong trade winds in the south-central Caribbean, and in the Gulf of Venezuela. Moderate to fresh trades dominate the E basin as well as the SW Caribbean and Gulf of Honduras, with gentle E winds elsewhere in the NW Caribbean. Seas are 8 to 10 ft in the south- central Caribbean, with highest seas near the coast of Colombia, 5-7 ft in the central and eastern basin, and 3 to 5 ft in the NW Caribbean, except in the lee of Cuba where seas of 1-3 ft are noted. The trades will continue to carry isolated to scattered passing showers. For the forecast, the pressure gradient between a ridge across the northern Caribbean Sea and the Colombian/Panamanian low will continue to support fresh to strong trade winds over the south- central Caribbean and in the Gulf of Venezuela through Fri night. Moderate to fresh trades will prevail elsewhere. High pressure will strengthen over the western Atlantic by tonight, and fresh to locally strong NE winds will develop in the Windward Passage, the lee of Cuba and S of Hispaniola through Mon night. ATLANTIC OCEAN... A cold front extends from 31N75W to central Florida. Scattered showers are near the front. Farther E, a band of showers and thunderstorms is ahead of a surface trough that extends from near Bermuda to 27N72W. Fresh S to SW winds are observed on either side of the trough axis, particularly N of 29N between 63W and 69W. Fresh to locally strong northerly winds follow the front. Elsewhere W of 65W, gentle to moderate winds are noted N of 27N and S of 22N, with light and variable winds from 22N to 27N where a ridge axis is present. Seas of 3-5 ft prevail N and E of the Bahamas, building to 5-7 ft N of 30N E of 77W. For the forecast west of 65W, the above mentioned cold front will move across the northern forecast waters through tonight before dissipating. High pressure will build across the region in the wake of the front, producing moderate to fresh NE to E winds S of 22N, and mainly gentle to moderate winds N of 22N through Sat night. Another cold front will move off NE Florida on Sun, and reach from 31N65W to South florida by Sun night. The front is forecast to dissipate over the SE waters on Mon. High pressure behind the front will likely bring fresh to strong NE to E winds mainly across the waters S of 27N by Mon night into Tue. Refer to the special features section above for details on the Gale Warning in the east Atlantic. Strong high pressure of 1036 mb located over the Azores extends a ridge over the remainder of the Atlantic forecast waters. The pressure gradient between this system and lower pressures in the vicinity of the ITCZ, continues to support fresh to strong trade winds and seas of 8-11 ft mainly across the region N of 10N and E of 50W. Seas of 7-8 ft in NE swell continue to propagate across the waters E of the Lesser Antilles. This will gradually subside today. 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 near and SW of the volcano. $$ GR