000 AXNT20 KNHC 111153 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Jan 11 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 1115 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: As of 09Z, low pressure of 1015 mb is centered over the northwest Gulf of Mexico near 28N91W, while strong high pressure is present to its west anchored by a 1031 mb high center near the Texas panhandle. The associated ridging extends south-southeastward toward the western Gulf waters. The earlier northerly gale force winds that occurred during the overnight hours behind the low and front have diminished to strong speeds there, but remain at gale force strength over the western part of the central Gulf from 22N to 25N west of 96W as was revealed by an overnight ASCAT pass. Wave heights with these winds are in the range of 9-13 ft. The low will gradually weaken as it reaches to near 29N90W 1015 mb at about daybreak this morning, with the cold front trailing from it to 26N92W and to Veracruz. The low will track northeastward across the rest of the north- central Gulf waters today and east- northeastward across the NE Gulf tonight. The gale force northerly winds will be confined to offshore Veracruz by early this afternoon, then diminish to strong winds tonight. Caribbean Sea Gale Warning: The pressure gradient between high pressure north of the area and the Colombian/Panamanian low has is currently bringing strong to minimal gale force winds within about 90 nm of the coast of Colombia. These winds will soon diminish, but will pulse up to gale force intensity again overnight tonight into Tue morning from 12/0600 UTC to 12/1500 UTC and repeat again Tue night into early Wed morning at about the same times. Wave heights are forecast to build to 11-13 ft in the gale force wind area. The Atlantic high pressure will have weakened enough afterwards as it shifts eastward across the central Atlantic to not allow for a recurrence of these winds reaching gale force later in the week. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details on both gale warnings. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic Ocean near the coast of Sierra Leone near 09N13W and continues to 04N21W, where overnight scatterometer data indicated it transitions to the ITCZ to 03N30W to 01N39W and to the coast of Brazil at 00N49W. Scattered moderate convection is seen within 180 nm north of the ITCZ between 24W-27W, within 120 nm north of the trough between 18W-22W and within 90 nm south of the trough between 16W-19W. GULF OF MEXICO... Gale force winds are occurring over a section of the western Gulf of Mexico. Please see the Special Features section above for details. As of 09Z, a cold front extends from the Special Features aforementioned 1015 mb low pressure that is centered 28N91W south-southwest to 23N94W and to inland Mexico just north of Veracruz. A warm front extends from the low east-northeastward to near 29N86W. Latest satellite imagery and NWS Doppler radar imagery show patches of rain along with scattered moderate rain showers over the far north-central Gulf north of 27N between 87W-91W to inland the northern Gulf coast. This activity is tracking east-northeast at a pretty good clip. Patches of rain with embedded scattered showers are along the cold front south of 22N and extends eastward to near 92W. Strong northwest to north winds are elsewhere west of the front outside the gale force wind area described above. Strong north to northeast winds are noted north of the low and west 91W, and also north of 28N between 88W and 91W as indicated by the overnight ASCAT data pass and by latest and current buoy observations. Strong southerly winds are east of the front to near 88W, and also north of 26N along with wave heights of 8-11 ft. The front will exit the southeastern Gulf Tue night and be over the Straits of Florida Wed. High pressure will build over the NW Gulf in the wake of the front, allowing for winds to diminish and seas to subside across much of the basin, with the exception of the SW Gulf. A trough will persist over the far SW Gulf Tue and Wed. The pressure gradient between the trough and a ridge across the eastern slopes of the Sierra Madre Mountains in Mexico will support fresh to strong northwest to north winds south of 26N and west of 96W on Tue. These conditions will persist on Wed, with seas building to 8-9 ft. On Wed, northwest to north winds in the range of 25-30 kt are expected near the Veracruz area. Looking ahead, another cold front will move into the northern Gulf on Fri and reach from the NE Gulf to the central and SW Gulf areas by late Fri. Fresh northerly winds are expected behind this front. CARIBBEAN SEA... A Gale Warning is in effect near the coast of Colombia. Please see the Special Features section for more information. Overnight ASCAT data passes highlighted fresh to strong northeast to east winds over a good portion of the the south-central Caribbean. Fresh winds prevail across the remainder of the Caribbean Sea. Near gale to minimal gale force winds are presently occurring near the coast of Colombia. Clusters of scattered moderate showers and thunderstorms supported by an upper-level disturbance that is riding northeastward across the western periphery of a broad upper anticyclone are noted over the western Caribbean from 15N to 21N west of 80W and south of 15N west of 80W. Isolated showers and thunderstorms are north of 15N between 74W-80W. Fresh to strong trades over much of the central Caribbean will continue through late Wed night, then diminish to mainly fresh speeds through Fri. A weakening cold front is expected to move into the northwestern Caribbean Wed, then become stationary from west- central Cuba to the northwestern Caribbean and dissipate by early Thu as high pressure builds from the Gulf of Mexico southeastward across the northwestern Caribbean. ATLANTIC OCEAN... A cold front extends from near 32N48W to 27N57W and to 24N62W, where it becomes stationary to just north of the eastern tip of Cuba near 21N74W. Scattered showers and a few thunderstorms are within 120 nm east of the front north of 27N. Broken to overcast low and middle clouds with embedded isolated showers are within 60-90 nm east of the front from 25N to 27N and within 60 nm southeast to south of the front south of 25N. A patch of scattered showers is confined to along and near the stationary front. A trough is ahead of the cold front along a position from 26N57W to 19N61W. No significant weather is occurring with this trough. Overnight ASCAT data passes showed generally gentle to moderate winds over the western Atlantic south of 25N west of the frontal boundary to near 77W. Light to gentle winds are elsewhere over the western Atlantic. The stationary front will weaken today and gradually dissipate through Tue. A weak cold front is expected to move over the northwest part of the area Tue, then become stationary across the far northern waters Wed southwest to near 30N77W, where it will transition to a weak cold front to near South Florida. A slightly stronger cold front will then overcome the stationary front and weak cold front as it sweeps across the western part of the area late Wed night and across the rest of the forecast waters Thu into early Fri. Yet a stronger cold front is expected to be along the southeast U.S. coast Fri night. Winds and seas will begin to increase late Fri off northeast Florida. The remainder of the Atlantic is under the influence of a ridge, anchored by a 1031 mb high pressure center that is analyzed south of the Azores near 32N27W. A large area of fresh to strong trades are south of the high from 07N-24N between 65W and the west coast of Africa. Near gale northeast winds are east of the Cape Verde Islands from 13N-22N between 17W-23W. These winds will change little today. $$ Aguirre