000 AXNT20 KNHC 191053 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 553 AM EST Wed Dec 19 2018 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 1045 UTC. ...Special Features... ...Gulf of Mexico Gale warning... On 20/1800 UTC a cold front over the Gulf of Mexico will extend from 30N85W to 21N88W. Gale force NW winds will be N of 25N W of 91W, with seas 10 to 13 FT. ...Atlantic Gale warning... On 21/0600 UTC Gale force S to SW winds will be in advance of a cold front, NW of line from 31N69W to 23N81W, with seas to 11 ft. ...MONSOON TROUGH/ITCZ... The monsoon trough passes from N Liberia near 07N11W to 04N18W. The ITCZ continues from that point to 01N30W to N Brazil near 00N50W. Isolated moderate convection is noted S of the monsoon trough from 00N-05N between 00W-16W. Widely scattered moderate convection is along the ITCZ from 02S-05N between 27W-50W. GULF OF MEXICO... A surface trough is over the NW Gulf of Mexico from 30N94W to 27N97W. Scattered showers are within 30 nm of the trough. A 1019 mb high is centered over N Louisiana near 32N91W. 5-15 kt E to SE surface winds are over the Gulf, E of the trough, with strongest winds over the NW Gulf. An upper level low over central Texas is progressing eastward supporting diffluence across the northwest Gulf of Mexico. A strong cold front with widespread thunderstorm activity will race across the Gulf waters tonight through early Fri. Gale force winds will develop west of the front on Thu, with seas building to near 20 ft. A post-frontal surface high pressure will set up over the central gulf on Sat, and move to the NE waters on Sun. CARIBBEAN SEA... A 1014 mb surface low is centered over the west Caribbean near 17N86W. A surface trough extends from the Yucatan Peninsula near 20N89W to the low center to 16N82W. Scattered showers are over the NW Caribbean from 16N-21N between 82W-89W. Scatterometer data depicts gentle to moderate trades across most of the Caribbean. Fresh to strong winds are noted south of 15N between 72W-78W. Fresh to strong winds will continue across the south-central Caribbean through Sun, increasing to near gale force near the coast of Colombia each night. A frontal trough will drift NW and slowly dissipate in the NW Caribbean today. Strong southerly flow will develop across the W Caribbean tonight ahead of a cold front entering the Yucatan Channel on Thu. The front will reach from the Windward Passage to Nicaragua this weekend. ATLANTIC OCEAN... The tail-end of a cold front is over the W Atlantic from 30N57W to 28N70W to 31N77W. A surface trough is over the central Atlantic from 31N53W to E Cuba near 21N76W. Scattered moderate convection is within 90 nm E of trough N of 25N. Scattered showers are elsewhere within 60 nm of the trough. A 1025 mb high is over the E Atlantic near 29N33W. The surface trough will drift NW today. Strong southerly flow will develop north of the Bahamas on Thu, increasing to minimal gale force Thu night on both sides of a strong cold front moving off Florida. The front will reach from 29N65W to Hispaniola Sat night, with associated winds and seas steadily subsiding on Sun and Mon. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa