000 AXNT20 KNHC 310559 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu Dec 31 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 0520 UTC. ...GALE WARNING IN THE ATLANTIC OCEAN... The 12-hour forecast consists of a cold front along 31N44W 27N45W 24N59W. Expect NW gale-force winds, and sea heights ranging from 12 feet to 18 feet, N of 29N between 47W and 52W. Expect the gale-force winds to last for the next 24 hours or so, after the beginning of those conditions. 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 passes through the southern coastal sections of Sierra Leone near 07N12W, to 06N22W. The ITCZ continues from 06N22W, to 05N31W, 04N33W, and to 04N48W. Precipitation: widely scattered moderate to isolated strong is within 120 nm to the north of the ITCZ between 25W and 43W, and from the ITCZ southward between 32W and 42W, and elsewhere from 10N southward between 43W and 60W. GULF OF MEXICO... Surface anticyclonic wind flow spans the entire Gulf of Mexico. A surface ridge extends from the Florida Big Bend, into the central Gulf of Mexico, to the Isthmus of Tehuantepec of southern Mexico. The return southerly wind flow is in advance of a Texas-to-Mexico frontal boundary. The cold front is forecast to reach the NW Gulf of Mexico this morning. Fresh to strong southeasterly winds will prevail across most of the basin through Thursday. A developing low pressure system will trail a cold front into the NW Gulf of Mexico on Thursday. Large seas associated with the front are expected in the western and central Gulf of Mexico on Thursday and Friday. The front will stall briefly, from the Florida Panhandle to near Tampico Mexico by Friday night. Reinforcing cold air will push a cold front southward into the eastern Gulf of Mexico this weekend. CARIBBEAN SEA... Current water vapor imagery, and the GFS model for 250 mb, show a ridge that extends from northern Colombia, to the NE corner of Nicaragua/E sections of Honduras, to the Yucatan Peninsula, across the Gulf of Mexico, to northern sections of Florida. The GFS model for 500 mb shows that an east-to-west oriented trough extends from the NE corner of the Caribbean Sea, to Puerto Rico and Hispaniola, to the Windward Passage. Precipitation: broken to overcast multilayered clouds and possible rainshowers cover the Caribbean Sea from 12N northward from 75W westward. The monsoon trough extends from northern Colombia near 11N73W, across Panama, beyond NW Costa Rica, and into the eastern Pacific Ocean. Precipitation: isolated moderate is from 12N southward from 70W westward. Rainshowers are possible elsewhere, in scattered to broken low level clouds, that are moving through the area, from 70W eastward, and elsewhere from 70W westward. Fresh to strong northeasterly winds will veer during the next 24 to 36 hours, as strong high pressure that is to the north of the area shifts eastward. Fresh to strong trade winds and large seas are expected across most of the eastern and central Caribbean Sea, from Friday through the weekend. ATLANTIC OCEAN... A cold front passes through 32N49W, to 30N51W, 28N60W and 26N67W. The front is dissipating from 27N67W to 27N74W. Precipitation: broken to overcast multilayered clouds and possible rainshowers are to the northwest of the line that runs through 32N44W to 27N50W. Broken to overcast multilayered clouds and possible rainshowers also are from 24N northward from 50W westward. A 1012 mb low pressure center is near 18N47W. A surface trough is along 18N42W to the low pressure center, and from the low pressure center to 15N55W. Precipitation: scattered moderate to widely scattered strong from 17N to 20N between 42W and 46W. Broken to overcast multilayered clouds and isolated moderate are elsewhere from 15N to 27N between 34W and 47W. A 1012 mb low pressure center is near 31N32W. A surface trough extends from the low pressure center to 28N20W. Precipitation: widely scattered moderate to isolated strong is within 270 nm of the center in the NE semicircle. The current dissipating cold front, along 27N west of 65W, will stall and weaken overnight. Strong high pressure that is to the north of the front will shift east-southeastward through Friday. Fresh to strong trade winds and large seas will prevail across the southern waters through Friday night. A cold front will move to the east of Florida on Sunday. $$ mt/dm