000 AXNT20 KNHC 120006 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 706 PM EST Sun Feb 11 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... Caribbean Sea Gale Warning: A tight surface pressure gradient between the strong surface ridge over the north Atlantic Ocean and lower pressure over northwestern South America will continue to support gale-force winds off the coast of Colombia. These conditions will continue through at least mid week. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Liberia, Africa near 04N08W continuing to 01N14W. The ITCZ begins near 01N14W and extends along 01S24W to the coast of Brazil near 03S39W. Scattered showers are within 150 nm either side of these boundaries. ...DISCUSSION... GULF OF MEXICO... A cold front extends across the northwest Gulf waters from 29N90W to 25N97W. A pre-frontal trough extends from the Florida Panhandle to 29N85W to 28N90W. Upper level diffluence ahead of the front support numerous heavy showers N of 28N between the Florida Big Bend and 91W. Scattered showers are ahead also ahead of the front over the western half of the basin, including the Bay of Campeche where a surface trough extends from 22N95W to 18N92W. Patchy fog continue to be reported in the northern Gulf N of 26N, ahead and behind the front. Fresh to strong northerly winds are north of the front while moderate southerly winds prevail south of it. The front will reach from southeast Louisiana to near Brownsville, Texas tonight, and from the western Florida Panhandle to the western Bay of Campeche by Mon evening where it will stall and weaken. Fresh to strong northerly winds and building seas to 8 ft will continue to follow the front tonight and Mon. Winds and seas will diminish by Tue as a ridge develops over the southeast United States. This pattern will support fresh east winds by mid week. CARIBBEAN SEA... Please refer to the SPECIAL FEATURES section above for details about the gale-force winds expected near the coast of Colombia. GOES-16 water vapor imagery continues to show deep layer stable, dry air across most of the basin, which is supporting generally fair weather conditions. The exception is Hispaniola where a diffluent wind environment at the mid-levels and patches of shallow moisture support scattered to isolated showers. Strong high pressure north of the area continues to support fresh to strong trade winds across the eastern and central Caribbean, as noted in latest scatterometer data. Seas are reaching 8 to 12 ft, except near the Colombia coast where seas will be up to 16 ft. The areal extent of the strong trade winds and associated seas will spread westward through mid week, including the Windward Passage and lee of Cuba. Otherwise, little change is expected. ATLANTIC OCEAN... Broad surface ridging anchored north of the area by a 1040 mb high near 41N35W extends S across the basin. The ridge is supporting moderate to fresh winds over most of the basin. A cold front is expected to move off the northeast Florida coast by Tue afternoon, followed by fresh northerly flow and building seas north of the Bahamas, then diminish through mid week as the front stalls and dissipates. Over the eastern Atlantic, moderate to fresh northeast winds dominate this region, except for strong winds north of the Cape Verde islands. 8-10 ft seas could be expected in this area. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos