000 AXNT20 KNHC 230930 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sat Jan 23 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 0900 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: 1018 mb high pressure north of Puerto Rico and low pressure over northern Colombia is resulting in a tight pressure gradient in the south-central Caribbean. Winds are pulsing to gale force during the overnight and early morning hours which will continue through the next several days. Seas will build to 11-12 ft around sunrise each day. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa at the Cote d'Ivoire and Liberia border near 04N08W to 04N27W. The ITCZ extends from 04N27W to 05N50W. Scattered moderate and isolated strong convection is noted from 05N-07N between 13W-17W, from 02N-04N between 17W-20W, from 00N-05N between 27W-33W, and from 04N-05N between 42W-49W. Scattered moderate convection is noted from 01N-03N between 47W-51W near the coast of northern Brazil. GULF OF MEXICO... Patchy to areas of dense fog is noted across portions of the Gulf coastal waters early this morning, with the potential for visibilities to be reduced to 1 nm or less. This fog should diminish by late morning. Otherwise, fair conditions are noted across the basin. A surface ridge extends from high pressure east of the southern Bahamas across the upper Florida Keys and Florida Bay to the north-central Gulf. A surface trough is analyzed in the western Gulf from 29N93W to 26N96W to 21N97W. A stationary front extends from northern Florida to across the northern coastal waters. Earlier scatterometer data showed mainly light to gentle anticyclonic winds under the ridging and gentle to moderate NE winds behind the front, with N-NE moderate winds west of the Yucatan Peninsula. Seas are mainly 3 ft or less across the basin per recent buoy observations and altimeter data. The stationary front will retreat northward as a warm front through the remainder of the weekend. High pressure will rebuild over the southeast U.S.A. with increasing southerly return flow and building seas Sun into early next week. The ridge will weaken late Mon as a weak cold front moves into the western Gulf, stalling by early Tue. The front will then get reinforced and progress eastward across the basin through the remainder of the week. CARIBBEAN SEA... Refer to the Special Features section above for details on an ongoing Gale Warning in the south-central Caribbean northwest of the coast of Colombia. Elsewhere, mainly gentle to moderate trades prevail, except moderate to fresh in the central Caribbean. Seas are 3 ft or less in the northwest Caribbean, and mainly 4-7 ft elsewhere. Isolated tradewind showers are possible with no significant convection noted across the basin, however deep convection is occurring over portions of central to northwest Colombia and far eastern Panama. Mainly moderate to fresh trades will prevail through the next several days outside of the south-central Caribbean, pulsing to fresh to strong over the Gulf of Honduras on Mon through Wed. N swell will propagate into the Tropical North Atlantic waters from Mon night through Thu. A cold front may approach the Yucatan Channel from the northwest Thu night. ATLANTIC OCEAN... West of 55W, 1018 mb high pressure is noted east of the southern Bahamas and Turks and Caicos near 23N66W with a ridge axis extending west-northwest toward the upper Florida Keys. A cold front extends from 32N58W to 28N70W to near Jacksonville, Florida. Scattered showers are possible near the front with fair conditions elsewhere. Fresh to strong SW winds are occurring north of 27N and east of the front, with mainly gentle to moderate winds elsewhere. A set of large northerly swell with seas of 7-11 ft associated with the frontal system extend across the waters north of 27N and east of 70W, with 3-6 ft seas noted elsewhere outside of the Bahamas, except 4-7 ft east of 70W. The cold front will reach along 26N by this evening, while a reinforcing cold front merges with it along 25N by Sun morning. The merged front will stall along 20N off the coast of the Dominican Republic by Mon afternoon, and then dissipate on Tue. A new cold front will move across the northern waters Tue night shifting south while weakening through early Thu. Another cold front may move off the southeast U.S.A coast by Thu afternoon while parent low pressure rapidly intensifies north of the area through the end of the week. Gale force winds and very large seas are possible with this system, with storm force to near hurricane force winds possible north of 32N. East of 55W, a cold front extends from 1010 mb low pressure north of the area near 37N39W through 32N40W to 26N44W to 20N59W. Isolated to scattered showers are possible near the front, with scattered moderate convection noted north of 27N between the front and 37W. Fresh to strong SW winds are occurring north of 27N within 120-180 nm ahead of the front, while northerly swell of 7-11 ft covers the waters north of 20N, except 11-14 ft north of 27N between 37W-50W. A 1027 mb high pressure area is centered northwest of the Canary Islands near 32N20W with a ridge axis reaching from the high west-southwest through 27N35W to 23N55W. Moderate to fresh trades cover the waters south of 20N, with gentle to moderate trades found near the ridge. Seas of 6-9 ft in mainly fresh trade wind swell dominate the open waters of the tropical Atlantic. $$ Lewitsky