000 AXNT20 KNHC 230002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 702 PM EST Fri Dec 22 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. ...ITCZ/MONSOON TROUGH... The monsoon trough enters the Atlantic Ocean through Sierra Leone and continues to 05N20W. The ITCZ extends from 05N20W to 02N34W to 0N50W. Scattered moderate convection is from 01N-08N between 15W-31W and N of 0N E of the Prime Meridian. ...DISCUSSION... GULF OF MEXICO... A ridge extending from the SE CONUS dominates the Gulf waters and provides gentle to moderate southerly return flow E of 90W while a tighter pressure gradient in the western basin supports moderate to strong southerlies. This tighter gradient is associated with the next cold front that will enter the NW Gulf waters tonight. The front will reach from SE Louisiana to near Tampico, Mexico Saturday morning, and from the western Florida Panhandle to 23N94W to the central Bay of Campeche by Saturday night. Reinforcing stronger high pressure will push the front to a position from Tampa, Florida to 23N94W to the central Bay of Campeche by Sunday night. Fresh to near gale-force northerly winds and building seas of 8 or 9 ft are expected in the wake of the front on Saturday, with winds diminishing to 10-15 kt by Sunday afternoon. The front is then forecast to extend from south Florida to near 22N96W to 22N96W to 18N94W on Monday while weakening. CARIBBEAN SEA... Latest scatterometer data continue to show fresh to strong winds across the central Caribbean, while moderate to fresh NE winds continue across the Windward Passage. Patches of low level clouds, embedded in the trade wind flow are producing isolated to scattered passing showers over Hispaniola, Puerto Rico and the eastern Caribbean. High pressure N of the region will maintain strong trade winds over the central and southwest Caribbean, with near gale force winds near the coast of Colombia each night during the weekend. Fresh to strong NE winds are expected through the Windward Passage as well. ...HISPANIOLA... Low-topped trade wind showers are across the island and are forecast through early Sunday morning. High pressure over the west Atlantic will support pulses of fresh to locally strong winds across the Windward Passage during the weekend. ATLANTIC OCEAN... A cold front extends from a weak 1016 mb low pressure located near 32N56W to 27N72W where it stalls NW to 30N76W. The cold front will drift south and dissipate rapidly through early Sat. Recent scatterometer data indicate fresh to strong winds in the wake of the front but N of 29N between 63W and 70W. An area of showers is ahead of the front N of 27N between 49W and 53W. The remainder of the western Atlantic is under the influence of a ridge anchored by a 1026 mb high pressure located over the Carolinas. E of the front, a 1044 mb high pressure centered NE of the Azores extends a ridge across most of the E and central 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 N of 11N between the coast of Africa and 40W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos