000 AXNT20 KNHC 221156 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 656 AM 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 08N13W to 06N20W. The Intertropical Convergence Zone extends from 06N20W to 05N38W to 00N49W. Scattered showers are from 03N-10N between 12W- 35W. ...DISCUSSION... GULF OF MEXICO... Mid to upper-level ridging is noted on water vapor imagery over the entire basin along with deep layer dry air, which is supporting clear skies and fair weather. A 1020 mb surface high is centered over the central Bahamas and extending across the basin. Light to gentle variable winds dominate the eastern half of the basin while moderate southeasterly winds prevail over the western half of the Gulf. A weak frontal boundary extends across northern Florida with no significant convection. The next cold front is forecast to come off the coast of Texas on Friday night and prevail through the weekend. Fresh to near gale- force northerly winds will follow the front starting on Saturday. CARIBBEAN SEA... Broad mid to upper-level ridging prevails over the Caribbean basin with water vapor imagery indicating very dry and stable air aloft supporting fair weather at the surface. A surface ridge anchored across the central Bahamas continues to support a tighter pressure gradient across the central Caribbean, resulting in fresh to strong trades in this area. Strong to near gale-force winds are expected along the coast of Colombia. Little change in the synoptic pattern is expected through early next week. ...HISPANIOLA... Broad mid to upper-level ridging along with deep layer dry air continue to support fair weather conditions over the island. High pressure over the west Atlantic anchored by a 1020 mb high over the central Bahamas supports pulses of fresh to strong winds across the Windward Passage through the weekend. While overall tranquil conditions are expected, isolated low-topped trade wind showers are possible during the weekend. ATLANTIC OCEAN... A 1018 mb surface low is centered north of the area of discussion. Its weakening cold front extends southwest reaching northern Florida. A cold front extends from the low to the southeast to 29N69W to 31N62W. A pre-frontal trough extends from 29N62W to 27N71W to 27N80W. Another trough extends to the east from 31N53W to 26N59W. Scattered showers are noted between these troughs mainly north of 28N. The remainder west Atlantic is under the influence of a surface ridge anchored by a 1020 mb high centered across the northern Bahamas near 24N77W. To the east, a mid to upper-level low supports a surface trough that extends from 26N38W to 17N39W. Scattered showers are occurring within 120 nm on either side of the trough. The remainder of the eastern Atlantic is under the influence of a surface ridge anchored by a 1042 mb high centered northwest of the Iberian peninsula near 43N17W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA