000 AXNT20 KNHC 211025 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Dec 21 2020 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 1015 UTC. ...SPECIAL FEATURES... Atlantic Gale Warning: A cold front is west of the area over the Gulf of Mexico as of 06Z extending from a 1010 mb low pressure near 31N81W to 19N92W. The low is forecast to strengthen as it moves northeastward into the western Atlantic. Winds ahead of the front will reach gale force north of 29N and within about 90 nm east of the front through tonight. Seas are expected to build up to 12 ft within the area of gale force winds. Please read the latest High Seas Forecast at https://www.nhc.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the border of Sierra Leone and Guinea near 09N13W to 08N16W, where it transitions to the ITCZ to 05N30W to the coast of Brazil near 03N51W. Scattered moderate convection is within 60 nm either side of the ITCZ between 21W- 28W. Scattered moderate convection is noted within 120 nm north and 60 nm south of the ITCZ between 15W-45W. GULF OF MEXICO... A cold front extends from a 1010 mb low pressure near 31N81W to 19N92W. A pre-frontal trough extends from 27N83W to 25N83W. NWS Doppler Radar and satellite imagery show scattered showers and thunderstorms within 60 nm of the trough. A 1021 mb surface high is analyzed over the far NW Gulf near 28N95W. Latest ASCAT data shows fresh northwest winds behind the front to near 90W and fresh to strong northwest to north winds along and just offshore Veracruz, Mexico. Moderate to fresh winds are west of 90W, except for light to gentle winds west of 93W. As for the forecast: The cold front will exit the southeastern Gulf this morning followed by fresh northwest to north winds. High pressure centered over the NW Gulf will shift eastward to northeast of the Gulf by late Tue allowing for southerly flow fresh winds to develop over western Gulf and gentle to moderate east winds to exist across the rest of the Gulf. A strong cold front is forecast to move across the area on Thu followed by possible gale force winds in the SW Gulf. CARIBBEAN SEA... Latest ASCAT data depicts fresh to strong trade winds over the south-central Caribbean and in the Gulf of Venezuela. Fresh northeast winds are noted south of Hispaniola. These winds are the result of the pressure gradient between high pressure located over the western Atlantic and lower pressure associated with the Colombian/Panamaniam low. These winds will persist during most of the forecast period. Patches of low-level moisture, embedded in the trade wind flow, are noted moving westward across the basin mainly north of about 14N. Scattered passing showers are possible with some of these clouds. As for the forecast: The cold front currently moving across the southern Gulf of Mexico is forecast to reach the Yucatan Channel and western Cuba this morning. It is forecast to extend from central Cuba to northern Belize by tonight, then gradually weaken from eastern Cuba to the Gulf of Honduras on Tue. Another and stronger cold front is expected to reach the Yucatan Channel and western Cuba by Thu night. Fresh to strong northerly winds will follow this front. ATLANTIC OCEAN... A cold front is forecast to bring strong to gale force winds across the western Atlantic today. Please see the Special Features section for more details. Fresh to strong southerly winds in advance of the front are already present over the waters east of NE Florida to near 75W. Scattered showers and thunderstorms are moving northeastward over these waters. Farther east, a cold front enters the central part of the area near 31N37W to 28N42W, where it becomes stationary to 24N59W. Scattered showers are observed along the cold front mainly north of 29N. Latest buoy and ASCAT data indicates mainly moderate to locally fresh winds northeast to east winds north of the stationary front to near 29N and between 47W-57W. Gentle to moderate northeast to east winds are elsewhere north of the stationary frontal boundary. A surface ridge prevails over the east Atlantic, anchored by a 1028 mb high centered north of the Madeira Islands. The gradient between it and lower pressure to its south is allowing for generally fresh trade winds from 13N-24N and east of 35W to include the area of the Cabo Verde Islands and surrounding waters. As for the forecast: The frontal boundary over the central Atlantic will weaken and dissipate by this evening. A cold front is forecast to move off the Florida coast today, extend from the southeastern Bahamas to southern Cuba by Tue, and continue moving eastward on Wed. Gale force winds will develop ahead of the front off the Florida coast and north of the Bahamas today. Fresh to strong winds are expected behind the front. By the end of the week, a strong cold front will push off the northeast Florida coast enhancing winds and convection. $$ ERA