348 AXNT20 KNHC 122309 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Dec 12 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 0000 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: A rather strong cold front will move into the NW Gulf Sun night into Mon. Strong high pressure that will follow in the wake of the front will usher in fresh to strong north winds over mainly the western half of the basin, with the exception of northerly winds to gale force developing over sections of the western and SW Gulf Mon and Mon night. Wind and seas decrease Tue as the strong high pressure weakens while it shifts eastward across the area. Please read the latest HIGH SEAS FORECAST- https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Liberia from 06N10W to 10N17W, where latest scatterometer data indicates that it transitions to the ITCZ to 05N17W to 04N30W to 04N45W. Scattered moderate to isolated strong convection is noted along the ITCZ from 02N to 07N between 21W to 45W and north of 04N to 10N between 45W to the coast of Brazil. GULF OF MEXICO... Please see the SPECIAL FEATURES section above for details on an upcoming gale event to impact sections of the western Gulf. Broad upper-level ridging and associated anticyclonic wind flow spans the entire area. At the surface, a relatively weak cold front pushed into the NW Gulf from southwestern Louisiana to south of Corpus Christi, Texas. Gentle to moderate north to northeast winds are behind the front. A pre-frontal trough is analyzed from near Morgan City, Louisiana southwestward to 25N95W. Scattered showers are along and within 60 nm south of the trough between 95W-97W, while isolated showers are elsewhere along and near the trough. High pressure ridging stretches from the western Atlantic west-southwestward to northern Florida and to the north- central Gulf. As for the forecast: The aforementioned cold front will become stationary by this evening, then transition to a warm front tonight as it lifts inland the northern and NW Gulf tonight into Sun morning. A rather strong cold front will move into the NW Gulf Sun night and across the rest of basin Mon and Mon night. Gale force winds are expected behind this front over some sections of the western and SW Gulf. See SPECIAL FEATURES above for details. CARIBBEAN SEA... Upper-level ridging covers the western Caribbean and Central America, while broad troughing that extends from the central Atlantic is present over the rest of the Caribbean. Upper-level west-northwest winds over the western and central Caribbean transition to mainly west winds over the eastern Caribbean. Moderate to locally fresh trades continue across the Caribbean east of 80W early this afternoon, except for fresh to strong northeast to east winds within 90 to 120 nm of the Colombian coast. Seas with these winds are in the 6-9 ft range. Gentle northeast winds are occurring west of 80W. As for the forecast, the fresh to strong northeast to east winds near Colombia and offshore its coast will pulse nightly into the start of next week along the Colombian coast. A weakening cold front will move slowly southeastward across the Yucatan Channel and western Cuba Thu through Fri. ATLANTIC OCEAN... A cold front enters the area through 32N34W and extends to 28N42W, where it transitions to a stationary front to 25N57W, where it then become a shearline to 22N57W and to near 22N64W. ASCAT data revealed fresh northeast to east winds and a few strong wind occurrences north of the shearline to near 29N and also north of the cold front. Scattered moderate convection is seen about 120 nm on either side of the stationary front and the shearline between 48W-64W. Broad and weak upper-level cyclonic winds continue to be present from 07N to 20N between 40W and 60W. A surface trough is analyzed along a position from 22N56W to 10N57W and a second trough near 26N71W to 20N72W. No significant convection is noted in the vicinity of either trough. A 1031 mb high center is analyzed to the north of the area near 35N56W. Associated anticyclonic flow is over the central Atlantic to the north of the stationary front and shearline. A 1022 mb high pressure center is analyzed over the far eastern Atlantic near 33N17W. Its related anticyclonic flow is over the waters north of 18N and east of the the stationary front and shear line features. As for the forecast: The stationary front and shearline will dissipate tonight. Shower and thunderstorm activity will remain north of Hispaniola and Puerto Rico. High pressure building south north of the front and shearline will weaken. Strong southwest winds will develop in off the Florida coast Mon in advance of the next cold front. $$ Torres