000 AXNT20 KNHC 141700 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1200 PM EST Thu Dec 14 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 1200 UTC surface analysis and satellite imagery through 1630 UTC. ...SPECIAL FEATURES... A cold front will move into the Gulf of Mexico by early Fri morning. Northerly winds will rapidly increase to fresh to near gale force behind the front by sunrise Fri, then will increase to minimal gale force offshore of Mexico, reaching to offshore of Veracruz Fri night. Seas will build to 8-12 ft W of the front with the strong to gale force winds. Gale force winds are forecast to diminish by sunrise on Saturday. See latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. Strong high pressure will build N of the Caribbean by Friday evening resulting in a tight pressure gradient in the S central Caribbean where trades will increase to fresh to strong. The gradient will continue to strengthen through the weekend and gale force winds are forecast to pulse NW of the Colombian coast Fri night, Sat night, and Sun night. Seas will build to 8-14 ft in S central portions due to the gale and surrounding winds. See latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough transitions to the intertropical convergence zone along the coast of Guinea-Bissau near 08N14W and continues to 05N25W then westward to the coast of Brazil near 03N50W. Scattered moderate convection is observed from 04N to 06N between 20W and 30W. ...DISCUSSION... GULF OF MEXICO... A weak surface ridge anchored by a 1017 mb high in the south central Gulf of Mexico near 25N90W dominates the eastern half of the basin with broad moderate anticyclonic flow across the region. Jet dynamics aloft are supporting mid to upper level cloudiness across the northwest Gulf, but low to middle level dry air continues to support clear skies elsewhere. Looking ahead, a cold front is forecast to enter the northern Gulf by early Friday morning, then reach from the Florida Big Bend area in the NE Gulf to near Tampico Mexico by Fri evening, then stall from Tampa to the Bay of Campeche on Sat before lifting back to the W and NW through Sun. Gale force winds are forecast along the coast of Mexico near Tampico Fri night and Sat. See special features for further details. CARIBBEAN SEA... A dissipating stationary front reaches from eastern Cuba across the northwest Caribbean along 20N. Ahead of the front, the remnants of a former cold front are analyzed as a trough from near Jamaica to central Panama. Scattered cloudiness is noted near this features, and near the entrances to the Gulf of Venezuela, but mostly sunny skies dominate elsewhere. No significant showers or thunderstorms are noted. Fresh northerly winds still may be occurring between the trough over the southwest Caribbean and the coast of Nicaragua, but are likely diminishing. Light to moderate trades are in the remainder central and eastern basin. Winds are forecast to increase to 20-25 kt over the south central Caribbean tonight, with gale conditions possible Sat night and Sun night as high pressure builds N of area. ...HISPANIOLA... Cloudiness prevail along the north coast of Haiti due to the proximity of a surface trough and stationary front over eastern Cuba. Isolated light showers are still possible mainly over higher terrain through later this this afternoon. Then, moisture will diminish as the trough continues to weaken and drift westward. ATLANTIC OCEAN... A stalling cold front from 27N67W to across the SE Bahamas and eastern Cuba will gradually dissipate through early Friday. A ridge will build along 25N in the wake of the front. A weak cold front will move off the NE Florida coast early on Friday, reach from Bermuda to S Florida Saturday, then will stall and gradually dissipate along 25N through early next week as high pres from the SE United States builds eastward across the area. A cold front reaches from 31N58W to 26N67W, then extends farther to eastern Cuba as a stationary front. Scattered cloudiness and a few showers are noted within 60 nm of the frontal boundary, but otherwise fairly dry conditions persist, and no significant cloud cover or convection is noted. A ridge will build along 25N in the wake of the front. A weak cold front will move off the NE Florida coast early on Friday, reach from Bermuda to S Florida Saturday, then will stall and gradually dissipate along 25N through early next week as high pres from the SE United States builds eastward across the area west of 65W. The remainder of the Atlantic Ocean is under the influence of a 1035 mb high pressure located just south of the Azores. Fresh trade winds are noted in latest scatterometer satellite This high extends a ridge SW to near the NE Caribbean. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen