822 AXNT20 KNHC 172107 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 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 1800 UTC surface analysis and satellite imagery through 2100 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 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 Africa near the border of Sierra Leone and Liberia at 07N11W to 06N14W. The ITCZ continues from 06N14W to 04N26W to the coast of Brazil near 02N50W. Scattered moderate and isolated strong convection is noted from 02N-08N between 18W-48W. GULF OF MEXICO... A surface ridge extends from 1021 mb high pressure centered near the central Texas coast at 29N96W through the Straits of Florida. Fairly dry conditions are present, however broken to overcast clouds persist across the southeast half of the Gulf. No significant showers or thunderstorms are noted. Earlier scatterometer data indicated mainly gentle to moderate anticyclonic winds across the basin. Buoy, ship and altimeter data indicated seas of 3 ft or less across the northwest half of the basin, and 3-5 ft across the southeast half of the basin in lingering and decaying northwest-north swell generated by a cold front passage a couple of days ago. High pressure will dominate the Gulf waters over the next several days. Fresh to strong southerly return flow will set up over the northwest Gulf Mon night into Tue between the high pressure and lower pressure farther west over northeast Mexico. These winds will diminish some by the middle of the week. Fresh to locally strong winds are expected near and to the northwest of the Yucatan Peninsula through Wed night due to local effects. 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 stationary front extends across the northwest Caribbean from central Cuba to north-central Honduras. Upper level ridging and deep layered dry air is allowing for drier conditions in the eastern Caribbean. Earlier scatterometer data showed moderate to fresh N-NE winds west the front and south of 19N, with gentle to moderate N-NE winds west of the front and N of 19N. Moderate to locally fresh trades prevail east of the front outside of the south-central Caribbean as described in the Special Features section above. Seas are mainly 4-7 ft across the basin, except to 8 ft in the south-central Caribbean. The stationary front will dissipate through Mon. High pressure building in the wake of the front north of the region will bring increasing winds and building seas over the central and northwest Caribbean. Fresh to strong NE winds are also expected in the lee of eastern Cuba starting Mon night. ATLANTIC OCEAN... A cold front extends from near 32N58W to 24N71W where it then continues as a stationary front across the southeast Bahamas to central Cuba. Scattered showers are possible in the vicinity of the front, with isolated thunderstorms possible south of 26N within 90-120 nm south-southeast of the front. The main upper level dynamics supporting the front are lifting out to the north, allowing sustained winds and gusts to continue to diminish over the waters, except north of 29N within 60-90 nm ahead of the front where earlier scatterometer data indicated fresh to strong SW winds. Gentle to moderate winds prevail elsewhere west of 55W. Even though winds associated with the front have mainly diminished, lingering and large NW swell of 7-11 ft persists north of 26N and west of the front to around 75W, and north of 29N and east of the front to 60W. Seas of 3-6 ft cover the remainder of the waters outside of the Bahamas, with seas mainly 3 ft or less inside the Bahamas. For the forecast west of 55W, the front will completely stall tonight while a reinforcing by cold front moves into the area tonight into Mon. The merging front will extend from 27N65W to eastern Cuba Mon night, then reach from 24N65W to eastern Cuba on Tue while gradually weakening through the middle of the week. Another cold front will move southward into the waters between Bermuda and northeast Florida Wed night, and dissipate along 27N by late Thu. Another cold front is forecast to reach the northern waters on Fri. Farther east, a cold front extends from the Azores to near 30N38W, denting a ridge that prevails across the waters north of 20N. The ridge is supporting a broad area of moderate to fresh trade winds, with locally strong winds and accompanying 6-9 ft seas south of 22N, with gentle to moderate anticyclonic winds north of 22N. Seas are mainly 4-7 ft from 22N to 26N, with 7-15 ft seas north of 26N, the highest along 32N, in large NW swell generated by the parent low of the cold front located well north of the area. $$ Lewitsky