000 AXNT20 KNHC 170539 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu Dec 17 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 0510 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border areas of Sierra Leone near 08N12W, TO 05N14W, to 05N16W. The ITCZ continues from 05N16W, to 05N26W, to the Equator along 34W, to 01S41W. Precipitation: scattered to numerous strong is within 135 nm of the coasts of Sierra Leone and Liberia from 05N to 09N, within 150 nm to the north of the ITCZ between 19W and 26W, from 03N to 04N between 18W and 19W, and from 04N to 05N between 30W and 31W. Widely scattered moderate to isolated strong, in general, is elsewhere from 11N southward between 30W and 60W. GULF OF MEXICO... Upper level SW wind flow spans the entire Gulf of Mexico. A 1010 mb low pressure center is in the Florida Big Bend near 30N84W. A cold front extends to the southwest of the low pressure center, to 26N85W and 23N90W. The front becomes stationary at 23N90W, and it curves to the northern part of the Isthmus of Tehuantepec of southern Mexico. The earlier gale-force wind speeds, that were near the coastal waters of Veracruz in Mexico, have decreased to less than gale-force. Precipitation: broken to overcast multilayered clouds and isolated moderate rainshowers are to the south of the line that runs from 29N at the Florida west coast, to 26N90W, to the coast of Mexico at 24N; in Florida from 26N to 30N; and in the Atlantic Ocean to the north of the line that runs from the Florida east coast at 26N beyond 32N64W. Isolated moderate to locally strong is in the NW corner of the Caribbean Sea, and in the Yucatan Peninsula, from 16N to 21.5N between 86W and 91W. The current cold front extends from A 1011 mb low pressure center that is near 30N84.5W, to 25N86W to the central Bay of Campeche near 18.5N93.5W. The winds that are behind the front remain strong S of 24N, but they have diminished to less than gale-force. The winds and the seas in the Gulf of Mexico will diminish gradually through Friday, as high pressure builds across the northern Gulf and the front sinks SE of the basin. The next cold front will move into the northwest Gulf of Mexico by Saturday evening, and move slowly SE, through Monday. CARIBBEAN SEA... Broad upper level anticyclonic wind flow, with a ridge, spans the Caribbean Sea. A cold front/stationary front is in the Gulf of Mexico. The SW part of the frontal boundary is in the SW corner of the Gulf of Mexico. Precipitation: isolated moderate to locally strong is in the NW corner of the Caribbean Sea, and in the Yucatan Peninsula, from 16N to 21.5N between 86W and 91W. Rainshowers are possible, in scattered to broken low level clouds that are moving through the area, from 70W eastward, and from 14N northward from 70W westward. The monsoon trough is along 08N/11N from 73W in N Colombia, beyond Panama and Costa Rica. Precipitation: isolated moderate is elsewhere from 14N southward from 73W westward to the coasts of the countries of Central America. Weak high pressure, to the north of the area, is supporting moderate to fresh winds in the central Caribbean Sea. High pressure will begin to strengthen to the north of the area, from tonight through Thursday. The trade winds will be freshened across most of the basin. The wind speeds near Colombia will pulse to strong each night, through Saturday night. A weakening cold front will move slowly SE across the Yucatan Channel and the NW Caribbean Sea, from Thursday evening through Friday, before dissipating. Strong high pressure to the north of the front will produce fresh to strong NE trade winds across much of the area, on Friday and Saturday, before diminishing modestly on Sunday and Monday. ATLANTIC OCEAN... A 1010 mb low pressure center is in the Florida Big Bend near 30N84W. A cold front extends to the southwest of the low pressure center, to 26N85W and 23N90W. The front becomes stationary at 23N90W, and it curves to the northern part of the Isthmus of Tehuantepec of southern Mexico. Precipitation: broken to overcast multilayered clouds and isolated moderate rainshowers are: in Florida from 26N to 30N; and in the Atlantic Ocean to the north of the line that runs from the Florida east coast at 26N beyond 32N64W. An upper level trough is along 30N50W, to the NE corner of the Caribbean Sea near 16N62W. A surface trough is along 29N55W 23N60W, to 17N64W in the NE part of the Caribbean Sea. Precipitation: isolated moderate to locally strong is from 21N to 30N between 41W and 54W. Isolated moderate rainshowers are within 400 nm to the NW of the surface trough. A 1028 mb high pressure center is near 31N31W. Surface anticyclonic wind flow covers the Atlantic Ocean from 10N northward from the 29N55W 17N64W surface trough eastward. A cold front currently is exiting the SE U.S. coast. The cold front will slide slowly SE, and reach from near Bermuda through the central Bahamas to central Cuba, late on Friday morning. Expect fresh to strong southwesterly winds, ahead of the front, N of 28N, from tonight through Thursday. The front will weaken gradually, and become E-to-W aligned along 24N, on Sunday. $$ mt/ss