000 AXNT20 KNHC 292315 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Dec 30 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 2300 UTC. ...SPECIAL FEATURES... ...Atlantic Gale Warning... A cold front reaching from the eastern Azores to the central Atlantic near 20N45W will stall and dissipate west of 35W through tonight. A second, reinforcing cold front moving across the north central Atlantic will move across the waters north of 25N and east of 50W through Thu night, accompanied by winds to minimal gale force near 31N35W Thu afternoon. Very rough seas to 18 ft will also accompany the front in NW swell, with swell to 8 ft reaching as far south as 22N east of 55W through Thu night. Winds will diminish through Fri as the front stalls along 27N. Seas to 12 ft will linger through Fri north of 22N between 35W and 55W. ...Caribbean Gale Warning... High pressure centered northeast of the Bahamas will build through Fri, supporting fresh to strong trade winds across the central Caribbean Sea through Sun, with winds pulsing to minimal gale force off Colombia Thu night, with seas to 14 ft. Gale force winds are expected to pulse once again on Fri night. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more information. ...MONSOON TROUGH/ITCZ... The monsoon trough remains inland over Africa. The ITCZ extends from 06N11W to 03N33W to 02N50W near the coast of NE Brazil. Scattered moderate convection with embedded thunderstorms is noted from 01N to 06N along the length of the ITCZ. ...GULF OF MEXICO... The gradient between high pressure in the western Atlantic and lower pressure over eastern Mexico is generating moderate to fresh SE to S winds across the majority of the Gulf. Seas are predominately 5 to 7 ft over most of the basin, with seas 2-4 ft in the SE Gulf. For the forecast, surface high pressure centered NE of the central Bahamas will remain nearly stationary through Sun and support moderate to locally fresh return flow across the central and western basin, increasing to fresh to strong Fri night as the pressure gradient increases ahead of a strong cold front forecast to come off the coast of Texas Sat evening. Strong to near gale force northerly winds will follow this front, with gale conditions affecting the NW and SW basin Sun and Sun evening. The front is forecast to move east of the gulf Mon morning. Winds and seas associated with the front will gradually subside through Mon night. ...CARIBBEAN SEA... Please see the Special Features section for details about the gale warning in effect for the Caribbean. A 1021 mb high pressure centered north of the area is supporting fresh to strong trade winds across the central Caribbean. Seas are 5 to 8 ft across this area. Fresh E to SE winds are noted across the Gulf of Honduras and the eastern Caribbean with seas 4 to 6 ft. Elsewhere, moderate E to SE winds and 3 to 5 ft seas are observed. No significant shower or thunderstorm activity is evident at this time with waver vapor satellite imagery confirming very dry air dominates the basin. For the forecast, the high pressure centered NE of the central Bahamas will remain nearly-stationary through Sun, supporting moderate to fresh trade winds across the Caribbean, except for locally strong winds in the Gulf of Honduras, central Caribbean and portions of the SW basin. Gale force winds are expected off Colombia Thu night and Fri night. ...ATLANTIC OCEAN... Please see the Special Features section for details about the gale warning in effect for the Atlantic. A 1021 mb high pressure NE of the Bahamas near 27N67W dominates the weather in the Western Atlantic. This is generating mostly light to gentle anticyclonic flow and 3 to 5 ft seas west of 65W. Moderate SW winds are noted off the northeast Florida coast and moderate E winds extending 180nm north of the Greater Antilles. Farther east, a cold front extends from 31N28W to 19N47W in the central and eastern Atlantic. Scatterometer data confirms a fresh westerly breeze behind the front with strong SW winds extending 300 nm ahead of the front north of 24N. Scattered moderate convection is observed east of the front within 120 nm N of 23N. Near gale force winds expected in the vicinity of thunderstorms. Significant wave heights of 12-14 ft area noted from 26N to 31N between 30W and 50W with 8 ft seas extending as far south as 17N in the central Atlantic. The subtropical ridge extends from high pressure over the Iberian Peninsula to 20N35W. Gentle to moderate NE winds and 5 to 7 ft seas are observed south of the ridge. For the forecast west of 65W, high pressure centered NE of the central Bahamas will remain nearly-stationary through early Sun. The high pressure will weaken and move east Sun ahead of a strong cold front moving off the northeast Florida coast late Sun night. Strong to near gale force winds and building seas associated with the front will affect the offshore waters N of 26N Sun and Mon. $$ AReinhart