000 AXNT20 KNHC 180950 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Jan 18 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: High pressure building north of the area will continue to support strong to near gale force winds over the south-central Caribbean through the middle of the week. Overnight land breezes will allow these winds to pulse to gale force within 90 nm off the coast of Colombia, mainly between Cartagena and Barranquilla. 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 details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Sierra Leone at 09N13W to 05N25W. The ITCZ continues from 05N25W to the coast of Brazil near 00N48W. Scattered moderate convection is noted from 04N to 08N between 25W and 30W. GULF OF MEXICO... A surface ridge extends from 1021 mb high pressure over the northwest Gulf through the Straits of Florida. Dry conditions prevail over the northwestern portion of the basin, while scattered showers are noted across the southeastern portion. Recent buoy and platform observations along with scatterometer satellite data indicated light to gentle anticyclonic winds across most of the basin, while moderate winds are noted near the Yucatan Peninsula. Buoy, ship and altimeter data also indicated 2 to 4 ft. The high pressure over the northwest Gulf will shift east across the northern Gulf through Fri. Fresh to strong southerly return flow will set up over the NW Gulf tonight into Tue between the high pressure and lower pressure farther west over northeast Mexico. These winds will diminish some by mid week. This pattern will bring relatively warm and moist are across cooler shelf waters in the northwest Gulf, allowing the potential for sea fog by mid week over portions of the northwest and north-central Gulf. Farther south, a trough will form off the west coast of the Yucatan Peninsula each night through Wed night, supporting brief pulses of fresh to strong winds. CARIBBEAN SEA... There is a gale warning in effect for the south-central Caribbean. Please see the Special Features section above for more details. A dissipating stationary front extends across the northwest Caribbean from central Cuba to north-central Honduras. Moderate to fresh NE winds and 3 to 5 ft seas are noted over the northwest Caribbean. Gale force winds and 8 to 10 ft seas are noted off Colombia. Moderate to fresh trade winds are ongoing elsewhere across the southeast and south- central Caribbean, with 5 to 7 ft seas. Regional radars indicated isolated showers across the Windward Islands, the ABC Islands and Puerto Rico. Scattered showers are likely in the eastern part of the Yucatan Channel. For the forecast, A stationary front reaching from eastern Cuba to the Gulf of Honduras will dissipate this morning. High pressure building in the wake of the front north of the region will bring increasing winds and building seas over the southeast and south- central Caribbean, with winds pulsing to gale force off the coast of Colombia mainly at night through mid week. Fresh to strong NE winds are also expected in the lee of eastern Cuba tonight through Wed night. ATLANTIC OCEAN... West of 60W: A weakening cold front extends from near 31N54W to 27N60W where it then continues as a stationary front through eastern Cuba and across western Caribbean. Scattered showers are ongoing in broad swath from South Florida across the northern Bahamas to 31N75W. These showers are ahead of a developing cold front approaching the area from Georgia and the Carolinas. Moderate to fresh SW to W winds are evident ahead of this boundary over the waters north of 27N and west of 70W with 5 to 7 ft seas. 1018 mb high pressure is centered near 29N62W, supporting light to gentle breezes north of 27N between 60W and 70W. Seas are quite large in this area however, reaching 7 to 11 ft in lingering NW swell. Moderate trade winds persist south of 27N with 5 to 7 ft seas in open waters. For the forecast, the stationary front extending from 25N65W to eastern Cuba will dissipate today ahead of the developing reinforcing cold front, expected to move off the NE Florida coast later this morning. The stronger front will move rapidly east and extend from Bermuda to central Cuba by tonight, from 24N65W to eastern Cuba by late Tue, then stall and dissipate from 23N65W to the Windward Passage by late Wed. Another front will move southward into waters between NE Florida and Bermuda Wed night. The main portion of this front will lift to the northeast of the area Thu, leaving a trailing stationary segment to dissipate along 27N by late Thu. This will be followed by yet another front moving southward into the waters between Bermuda and NE Florida Fri. Farther east, the subtropical ridge supports gentle to moderate winds over the waters north of 20N, and moderate to fresh trades farther south. A large area of NW to N swell with significant wave heights reaching 8 to 13 ft are active north of 22N between 30W and 50W. Farther south, 6 to 8 ft seas prevail in a mix of N swell and shorter period easterly wind waves. $$ Christensen