000 AXNT20 KNHC 252311 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 611 PM EST Mon Dec 25 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 2300 UTC. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 05N08W to 05N11W. The ITCZ axis extends from 05N11W to 04N30W to the coast of Brazil at 00N50W. Scattered moderate convection is observed along the ITCZ between 23W-40W. ...DISCUSSION... GULF OF MEXICO... A cold front extends from south Florida to 24N89W to 23N95W where it becomes stationary to the western Bay of Campeche near Veracruz, Mexico. A well defined band of mainly low clouds with embedded showers is associated with the front across the area. Fresh to strong northeast winds and seas of 5-7 ft are behind the front across the north and west Gulf waters. The cold front will continue moving south over the Florida peninsula producing a wind shift across south Florida, but little change in temperatures. The western half of the front will lift north as a warm front across the western Gulf beginning tonight, and stall across the far north-central waters by mid-week. A low may form along the frontal boundary over the western Gulf on Wednesday. CARIBBEAN SEA... The most recent scatterometer data show fresh to strong winds are across the south-central Caribbean near the coast of Colombia, and fresh to strong winds across the remainder of the central Caribbean. Moderate to locally fresh trades are noted elsewhere across the basin. Patches of low level moisture embedded in the trade wind flow are producing isolated to scattered passing showers across the Greater and Lesser Antilles from time to time. This cloudiness is more concentrated over the NW Caribbean between the Cayman Islands and the Gulf of Honduras. Little change in this weather pattern is forecast over the next two or three days. Strong trades will persist over the Central and SW Caribbean through Thursday, with near gale-force nocturnal winds near the coast of Colombia. Locally strong northeast winds are expected through the Windward Passage on Tuesday evening. Large east swell will build seas to 9 ft east of the Lesser Antilles along 55W tonight and reach the east Atlantic passages on Tuesday evening through Thursday evening. ...HISPANIOLA... Low-topped trade wind showers will continue to move across the island. Mostly dry and stable conditions are expected to persist over the next couple of days under the influence of a mid-upper level ridge and associated strong subsidence. ATLANTIC OCEAN... A cold front enters the forecast area near 31N74W and extends across south Florida near 27N80W then into the Gulf of Mexico. Mainly low clouds with embedded showers are related to the frontal boundary. Latest scatterometer data indicate fresh southwesterly winds within about 75 nm ahead of the front north of 29N while fresh northwesterly winds prevail in the wake of the front. The front is expected to stall from 29N65W to the Straits of Florida tonight into early Tuesday, then gradually weaken through Thursday. The remainder of the forecast area is under the influence of a ridge anchored by a 1030 mb high located near the Azores. This system will undergo occasional intensity fluctuations, resulting in a rather tight pressure gradient across the waters north of the ITCZ/monsoon trough between the coast of Africa and the Lesser Antilles through at least Wednesday. Recent ASCAT passes provide observations of moderate to fresh winds around the southern periphery of the ridge east of the Lesser Antilles. Seas are in the 8-10 ft range within this area of winds based on altimeter passes. For additional information please visit http://www.hurricanes.gov/marine $$ ERA