000 AXNT20 KNHC 171000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Jan 17 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 1000 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: High pressure building north of the area will support strong to near gale force winds over the south- central Caribbean through mid 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 near 08N13W to 06N20W. The ITCZ continues from 06N24W to 02N40W and to the coast of Brazil near 00N50W. Scattered moderate convection is noted within 90 nm on either sides of both boundaries. GULF OF MEXICO... A surface ridge extends from 1016 mb high pressure centered over the western Gulf near 25N93W through the Straits of Florida. This high pressure is following a cold front that moved southeast of the basin yesterday. Light to gentle breezes cover the Gulf, except for moderate southerly flow over the southwest and west central Gulf. Seas are likely 5 to 7 ft in lingering NW swell over the eastern Gulf, although these seas are subsiding quickly. Seas are 1 to 3 ft in the northern Gulf, and are 3 to 5 ft elsewhere. Fairly dry conditions persist for now, and no significant showers or thunderstorms are noted. For the forecast, a weak front will stall along the north Gulf coast tonight, then dissipate. Southerly flow will increase across the western Gulf through late Mon, between the high pressure anchored over the central Gulf and lower pressure over west Texas and northwest Mexico. Fresh to strong SW winds and seas to 8 ft are possible over the northwest Gulf Mon night. The southerly flow will also bring increased moisture over the cooler shelf waters of the northwest Gulf, and patchy sea fog is possible by mid week there. Elsewhere, fairly tranquil marine conditions will persist through Thu as the high pressure shifts east of the area. CARIBBEAN SEA... There is a gale warning in effect for the south-central basin. Please see Special Features section for more details. A stationary front extends across the northwest Caribbean from eastern Cuba to central Honduras. A recent scatterometer shows moderate to fresh N to NE winds are evident north of the front over the northwest Caribbean. Seas in this plume are likely 4 to 6 ft. Grand Cayman radar is showing only a few showers along the front moving to the southwest. High pressure north of the area building in the wake of the front will support moderate to fresh trade winds with 5 to 7 ft over the remainder of the basin, but with strong trade winds and seas to 8 ft off Colombia. Other than a few showers moving into the Windward Islands, little shower activity is noted. For the forecast, the stationary front reaching from eastern Cuba to central Honduras will dissipate through Mon. The high pressure building in the wake of the front north of the region will bring increasing winds and building seas over the south- central Caribbean, with winds pulsing to gale force off the coast of Colombia mainly at night through mid week. ATLANTIC OCEAN... West of 60W, a cold front extends from west of Bermuda near 32N62W to eastern Cuba near 21N76W. Scattered showers are observed within 90 nm ahead of the front north of 29N. The main upper dynamics supporting the front are lifting out to the north, allowing sustained winds and gusts to diminish over the waters north of 25N. Seas are still very high, with the buoy 41048 near 32N69W reporting 18 ft significant wave heights. This is due to shorter period W to NW swell. Seas in excess of 8 ft cover most of the area north of 26N between 65W and 75W. Seas are 4 to 6 ft elsewhere in open waters with gentle to moderate winds. For the forecast for the waters west of 60W, the cold front from will stall from 25N65W to eastern Cuba late today, then will dissipate Mon. Another cold front will move southeast off the NE Florida coast tonight, reach from Bermuda to central Cuba by late Mon, then stall and dissipate from 23N65W to eastern Cuba through mid week. Another cold front will move southward into the waters between Bermuda and NE Florida Wed night, and become stationary along 25N into the central Bahamas by late Thu. Farther east, a cold front extends from the northwest Azores to near 30N41W, denting a ridge that prevails north of 20N. The ridge is supporting a broad area of moderate to fresh trade winds with 8 to 10 ft seas in mixed N and NE swell. $$ Christensen