000 AXNT20 KNHC 062353 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 653 PM EST Wed Dec 6 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. ...SPECIAL FEATURES... ...GALE-FORCE WINDS IN THE GULF OF MEXICO... A cold front extends from the Florida Big Bend to 27N91W where it transitions to a warm front that connects to a 1016 mb low near 26N95W. Another cold front extends from the low to 21N97W to 22N99W. Frequent wind gusts to gale force are north of the front with seas reaching 10 ft. Strong to gale force northerly winds and rough seas are expected in the wake of the front as it moves across the basin through Saturday morning. Latest model guidance indicates reinforcing cold air, with gale force winds over the west-central gulf on Thu, and over the SW gulf by Thu night. 12 ft seas are likely to occur in the central and western Gulf Thu through late Fri night, with peak wave heights close to 18 ft in the SW Gulf. Please read the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 for more details. ...ITCZ/MONSOON TROUGH... The Monsoon trough extends across Africa to the E Atlantic near 08N14W. The Intertropical Convergence Zone axis extends from 08N14W to 05N25W to 06N40W to 04N52W. Scattered moderate convection is from 02N to 08N between 21W and 41W. ...DISCUSSION... GULF OF MEXICO... A cold front extends from the Florida Big Bend to 27N91W where it transitions to a warm front that connects to a 1016 mb low near 26N95W. Another cold front extends from the low to 21N97W to 22N99W. Strong high pressure building north of the front is supporting frequent gusts to gale force over a portion of the northern Gulf, as well as strong to near gale force winds elsewhere N of the front. Please refer to the special features section for more details on this gale. Scattered showers are within 60 nm SE of the front, and extend NW of the front to the coastline. Mainly gentle to moderate winds are south of the front. Over the next 24 hours the low and front will continue to move very slowly to the SE. Thereafter, the upper trough supporting the frontal system will dig farther south, and allow the low to accelerate NE and bring the cold front across the remainder of the Gulf basin through Friday and Friday night. CARIBBEAN SEA... Deep moisture over the SW Caribbean is interacting with diffluent flow aloft and a surface trough from 17N81W to 10N82W to support scattered moderate convection S of 18N and W of 78W. Generally fair weather covers the rest of the Caribbean. Mainly moderate to fresh NE to E trades are over the basin today, except for strong winds S of 16N between 72W and 78W over the central Caribbean. The strong winds are expected to expand in coverage to between 70W and 70W tonight, then diminishing through late this week as the high pressure north of the region weakens while a frontal system crosses the Gulf of Mexico. This cold front will reach the NW Caribbean early Saturday and cross the NW Caribbean through Saturday night with strong to near gale force winds behind the front. ...HISPANIOLA... Isolated thunderstorms over the higher terrain this evening should dissipate through the late evening with the loss of daytime heating. This afternoon thunderstorm pattern is expected to repeat again Thursday. ATLANTIC OCEAN... A 1025 mb high is centered near 32N62W supporting generally fair weather over the SW north Atlantic. A cold front enters the area of discussion near 31N36W and extends to 23N42W to 18N55W to 19N67W. Scattered moderate convection is within 300 nm E of the front N of 21N. Scattered showers and isolated thunderstorms are within 90 nm S of the front S of 21N. Strong NW winds are behind the front N of 28N as far west as 55W. A pre-frontal trough void of deep convection extends from 20N35W to 15N38W. High pressure centered over Europe extends across the remainder of the eastern Atlantic. Over the next 24 hours the central Atlantic cold front will continue to progress eastward. A cold front will emerge off the north Florida coast. For additional information please visit http://www.hurricanes.gov/marine $$ Latto