000 AXNT20 KNHC 142338 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 638 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 1800 UTC surface analysis and satellite imagery through 2330 UTC. ...SPECIAL FEATURES... ...Gale Warning Gulf of Mexico... A cold front will move into the Gulf of Mexico by early Friday morning. With this, northerly winds will rapidly increase to fresh to near-gale force behind the front by sunrise Friday, then will increase to minimal gale-force offshore of Mexico, mainly south of 26N. Seas will build to 8-10 ft in the area with the highest winds. These conditions are forecast to diminish by sunrise on Saturday. See the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...Caribbean Gale Warning... Strong high pressure will build north of the Caribbean by Friday evening resulting in a tight pressure gradient in the south 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 northwest of the Colombian coast Friday night, Saturday night, and Sunday night. Seas will build to 8-11 ft in in this area. See the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough transitions to the ITCZ along the coast of Africa near 07N13W and continues to 03N50W. Scattered moderate convection is observed from 03N-09N between 20W-33W. ...DISCUSSION... GULF OF MEXICO... A surface ridge anchored by a 1018 mb high in the south central Gulf near 23N88W dominates the eastern half of the basin with broad moderate anticyclonic flow. Jet dynamics aloft are supporting mid to upper level cloudiness across the northwest Gulf, while clear skies prevail 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 northeast Gulf to near Tampico Mexico by Friday evening. The front will stall from Tampa to the Bay of Campeche on Saturday before lifting back to the northwest through Sun. Gale-force winds are forecast along the coast of Mexico near Tampico from Friday night to Saturday. See the Special Features section for further details. CARIBBEAN SEA... A weakening stationary front reaches from eastern Cuba across the northwest Caribbean along 17N. Ahead of the front, the remnants of a former cold front are analyzed as a trough that extends from 17N79W to 12N81W. Scattered showers are noted along the front and trough. Scatterometer data depicts light to moderate trades across the basin. Winds are forecast to increase to 20-25 kt over the south central Caribbean tonight, with gale conditions possible by Saturday night and Sunday night as high pressure builds north of the area. ...HISPANIOLA... Cloudiness prevail along the north coast of Haiti due to the proximity of a stationary front over eastern Cuba. Isolated showers are still possible mainly over higher terrain through this evening. Then, moisture will diminish as the trough continues to weaken and drift westward. ATLANTIC OCEAN... A frontal boundary was analyzed as a cold front from 31N73W to 29N76W. To the east, a weakening stationary front extends 31N53W to 21N76W. Isolated showers are noted along this boundary. The remainder of the basin is under the influence of a surface ridge, anchored by a 1032 mb centered near 37N29W. Another cold front will move off the northeast Florida coast early on Friday, reach from Bermuda to south Florida Saturday, then will stall and gradually dissipate along 25N through early next week as high pressure from the southeast United States builds eastward across the area. For additional information please visit http://www.hurricanes.gov/marine $$ ERA