000 AXNT20 KNHC 132354 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 654 PM EST Thu Dec 13 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...SPECIAL FEATURES... ...Gulf of Mexico Gale Warning... A cold front is forecast to enter the northwest Gulf of Mexico by early this afternoon. The front will shift across the Gulf waters, moving E of the Gulf Saturday. Gale force winds are expected tonight through Fri morning behind the front over the northwest and west-central Gulf waters, with winds diminishing later Fri. Please read the latest High Seas Forecast under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough remains inland in Africa. The ITCZ passes through the coastal sections of Guinea near 09N13W to 02N24W to 00N35W. Scattered moderate convection are along and within the ITCZ from 09N to 03N between the coast of Sierra Leone to 22W. Scattered moderate isolated strong convection is noted further south near the Equator from 01N to 05S between 08W-05W. Scattered showers are observed near the coast of Brazil from 09N southward to 02S between 35W-49W. GULF OF MEXICO... A cold front extends southward into S Texas from a 1002 low pressure with a surface trough 30 to 60 nm east of the front. The trough is supporting a cold front that is moving southeastward across Texas and towards the NW corner of the Gulf of Mexico. Broken to overcast multilayered clouds and numerous moderate to locally strong thunderstorms are moving northeast extending from the northern Gulf of Mexico to 24N88W. Scattered showers are noted further south into the Bay of Campeche near Tampico, Mexico from 25N-20N between 92W-97W. Fresh to strong southerly flow will continue east of a cold front that will move off the Texas coast late this afternoon into tonight. The front will reach from the Mississippi Delta to the Bay of Campeche tonight, from the Florida Big Bend to the Yucatan Channel late Fri, and move through the Bahama Channel on Sat. Strong to near gale-force northwesterly flow west of the front will increase to gale-force this evening over the northwest gulf waters, with 30-40 kt conditions spreading south across the west-central gulf late tonight into Fri. The pressure gradient will relax on Fri night and Sat, with moderate west flow expected on Sat evening as the seas subside to less than 8 ft. The gradient will continue to relax with light northerly winds on Mon. CARIBBEAN SEA... A surface trough is in the NW Caribbean Sea, along 20N85W to 16N85W in eastern Honduras. Scattered showers are possible in the vicinity of the trough and near the eastern coast of the Yucatan peninsula. Most of the Caribbean is relatively quiet with no significant convection and only some light showers. Fresh to strong trade winds will prevail across the S-central Caribbean through the upcoming weekend, with nocturnal pulses to near gale-force off the northwest coast of Colombia. These winds will expand north across the entire central Caribbean on Fri. A surface trough over the west Caribbean will gradually dissipate through Fri. A cold front will enter the Yucatan Channel on Fri afternoon, stall and then gradually dissipate over the NW Caribbean into early next week. Strong north winds are forecast west of the front across the Gulf of Honduras late Fri night and Sat. Large north swell will reach the Leewards on Sat, and spread south through the northeast Atlantic passages during the weekend. ATLANTIC OCEAN... A cold front passes through 31N45W to 27N52W to 24N61W then transitions to a stationary front at that point to 22N70W into the eastern Bahamas to 21N74W. Broken multilayered clouds and scattered moderate convection are 210 nm west of the front and 80 nm east of the line. One surface trough is along 45W from 23N to 17N. Scattered showers are possible in the vicinity of the trough. Further west, a second surface trough is along 57W from 22N to 13N. Scattered showers are possible in the vicinity of the trough. The frontal boundary north of the Windward Passage will drift north and extend east to west along 25N on Fri, and then gradually wash out as it continues north across the northeast portion on Sat. Strong to near-gale southerly return flow will develop north of the Bahamas tonight and Fri, all ahead of another cold front that will sweep east across the northern waters during the upcoming weekend reaching a position from Bermuda to northwest Cuba on Sun night and from 31N71W to central Cuba on Mon. The front will stall as it passes across the waters north of Antilles on Tue. For additional information please visit http://www.hurricanes.gov/marine $$ Torres