000 AXNT20 KNHC 232335 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 635 PM EST Sat Dec 23 2017 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...Gale Warning in the Gulf of Mexico... As of 2100 UTC, a cold front extends from Pensacola, Florida SW to 24N94W to the western Bay of Campeche near 18N95W. Latest scatterometer data show NW to N gale force winds behind the cold front S of 23N W of the front. The front will reach from the Florida Big Bend to the western Bay of Campeche Sunday morning, and then from central Florida SW to near Veracruz, Mexico Monday morning. Gale winds will diminish by early Sunday morning. By Monday night, gentle to moderate easterly winds will dominate most of the Gulf region with seas of 4-6 ft. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...Gale Warning for the coast of Colombia... High pressure over the Atlantic tightens the pressure gradient over the south-central and southwest Caribbean Sea, thus leading to gale-force winds off the coast of Colombia at night through Sunday. The high pressure will weaken Mon, but still will maintain strong trades over the Central and SW Caribbean through Wed, with near gale force nocturnal winds near the coast of Colombia. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough enters the Atlantic Ocean through Nigeria and and continues to 03N at the Prime Meridian to 03N16W. The ITCZ axis extends from 03N16W to 04N26W to 02N38W to NE Brazil near 0N50W. Scattered moderate to strong convection is N of 01S E of 03E. Scattered moderate convection is elsewhere from 0N to 05N between 02W and 14W and from 04N to 09N between 20W and 54W. ...DISCUSSION... GULF OF MEXICO... A cold front is moving across the Gulf waters. Please, see Special Features section for details. E of the front, a ridge from the Atlantic Ocean extends across Florida into the eastern Gulf of Mexico, and provides gentle to moderate southerly return flow ahead of it. The aforementioned ridge will continue to bring mostly clear skies, light winds, and warm temperatures across South Florida the remainder of the weekend. On Monday night, the cold front will move across South Florida where its tail will stall through Tuesday. CARIBBEAN SEA... Latest scatterometer data continue to show fresh to strong winds across the central Caribbean, while moderate to fresh NE winds persist across the Windward Passage. Seas of 11-13 ft are in this region with the strongest winds near the coast of Colombia. Patches of low level moisture embedded in the trade wind flow are producing isolated to scattered passing showers over the central and eastern Caribbean, including Hispaniola, Puerto Rico and the Lesser Antilles. Showers carried by the trades are aslo affecting the ABC Islands and parts of Central America, including the Gulf of Honduras. High pressure N of the area will maintain strong trades over the central and SW Caribbean through Wed, with near gale to gale force nocturnal winds near the coast of Colombia through Sunday. See special features for further details. Fresh to strong NE winds are expected through the Windward Passage as well. Large E swell will build seas to 9 ft E of the Lesser Antilles on Mon night, and on the E Atlantic passages on Tue evening. At that time, expect building seas to 10 ft. ...HISPANIOLA... Low-topped trade wind showers will continue to move across the island the remainder of the weekend. High pressure over the Atlantic will continue to support pulses of fresh to locally strong winds across the Windward Passage through Sunday. ATLANTIC OCEAN... A ridge dominates the western Atlantic, including the Bahamas and the State of Florida. A frontal trough extends from a weak low pressure of 1023 mb located near 30N53W to 25N53W to 21N55W. These features are forecast to dissipate over the next 24 hours. No convection is associated with these features. E of the frontal trough, a strong 1038 mb high pressure centered NE of the Azores extends a ridge across the remainder of the Atlantic. The pressure gradient between this strong high pressure and lower pressure in the vicinity of the monsoon trough/ITCZ is supporting fresh to strong winds mainly N of 11N between the coast of Africa and 40W, with seas of up to 12 ft. This high pressure has displaced the monsoon trough/ITCZ farther south. The next cold front will move off the NE Florida coast on Sun night, and stall from near Bermuda to Central Cuba by Tue. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos