000 AXNT20 KNHC 182330 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 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 1800 UTC surface analysis and satellite imagery through 2240 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. Nocturnal pressure fluctuations will cause 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 across equatorial Africa to the coast of Sierra Leone near 07N13W. The ITCZ continues from 07N13W to 02N34W to the coast of Brazil near 00N50W. Scattered moderate isolated strong convection is noted from 01N to 06N between 11W and 42W. GULF OF MEXICO... A 1022 mb high pressure is centered over the Gulf near 26.5N88W, and generally extends a broad ridge to the SE and to the NW. Dry and stable conditions prevail over most of the Gulf. Scattered showers are along and just east of a coastal trough along the Mexican coast from near Cabo Rojo to Veracruz. Light to gentle anticyclonic winds prevail across most of the basin, while moderate to fresh southeast to south winds have developed this afternoon across west portions north of 21N and west of 94W, where seas are 4-6 ft. Elsewhere buoy, ship and altimeter data also indicate seas of 2 to 3 ft. High pressure over the Gulf will shift eastward across the northeastern Gulf through Fri. Fresh to strong southerly return flow will set up over the entire NW Gulf tonight into Tue between the high pressure and lower pressure farther west over northeast Mexico. These winds will diminish some by Wed. 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. Moderate to fresh NE winds and 3 to 6 ft seas are noted over the northwest Caribbean, to the north of an old frontal trough extending from the western Cayman Islands to the eastern Gulf of Honduras. Strong winds to 30 kt and 8 to 10 ft seas are noted off of Colombia. Moderate to fresh trade winds are ongoing elsewhere across the southeast and south-central Caribbean, with 5 to 8 ft seas. Scattered showers and isolated thunderstorms are present from 15N to 17.5N between 81W-86W and in the Yucatan Channel. High pressure will begin to shift over the far western Atlantic today and increase the pressure gradient across the southeast and central Caribbean. This will produce 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 Thu morning. Fresh to strong northeast winds are also expected in the lee of eastern Cuba tonight through Wed night, diminishing to fresh winds Thu and to gentle to moderate on Fri. ATLANTIC OCEAN... West of 45W: A weakening cold front extends from near 31N50W to 29N54W where it then continues as a stationary front to 27.5N62W. A cold front extends from a deepening 1001 mb low near 39N64W through 31N67W to 23N77W. Scattered showers are ongoing in broad swath from the Straits of Florida across the northern Bahamas to beyond 31N60W. Moderate to fresh SE to E winds are evident ahead of this boundary over the waters north of 25N and west of 63W with 5 to 7 ft seas. West of the front, fresh to strong westerly flow is noted from the northern Bahamas to 31N between 73W to 81W. A 1027 mb high pressure is centered over the far eastern Atlantic near 33N17W, extending W-SW to the southern end of the stationary front. The pressure gradient to the south is supporting moderate to fresh trade winds across the tropical Atlantic south of 25N where seas are 7 to 10 ft in NW to N swell. The cold front will become stationary from near 26N65W to 22N71W and dissipating to eastern Cuba by early Tue. The boundary will gradually dissipate through early Thu. Another cold front will move southward into waters between northeastern 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. $$ Stripling