000 AXNT20 KNHC 102318 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 618 PM EST Sat Feb 10 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 2330 UTC. ...SPECIAL FEATURES... Caribbean Sea Gale Warning: A tight surface pressure gradient between the strong surface ridge over the north Atlantic Ocean and lower pressures over northwestern South America will continue to support gale-force winds pulsing near the coast of Colombia through the next week, mainly at night. 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 waters along the 06N10W and reaches to 01N17W. The intertropical convergence zone continues from that point to 05S35W. Scattered showers are observed along the monsoon trough between 10W-15W. Scattered showers are also noted along the ITCZ west of 30W to the coast of Brazil. ...DISCUSSION... GULF OF MEXICO... A ridge extending from the western Atlantic through the central Gulf supports moderate southeast winds, except for moderate to fresh east winds over the Straits of Florida. Scattered showers and a few thunderstorms are active over the far northern Gulf along the coast of Louisiana. The moist southerly flow is allowing dense fog over mainly the coastal water across the northwest Gulf, with 3 NM visibilities over offshore areas of the northwest Gulf. No fog is currently observed elsewhere, but may develop over the eastern Gulf early Sun. The fog will lift across the northwest Gulf by early Sun afternoon as a cold front moves into the region off the Texas coast. The front will reach a position from southeast Louisiana to near Brownsville, Texas by Sun evening, and from the western Florida Panhandle to the central Bay of Campeche by Mon evening, where it will stall and weaken. Fresh to strong northerly winds and building seas to 8 ft will follow the front Sun night and Mon. Looking ahead, winds and seas will diminish into Tue as a ridge develops over the southeast United States. This pattern will support fresh east winds by mid week. CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details about the gale-force wind conditions expected near the coast of Colombia. GOES-16 water vapor imagery continues to show stable, dry air across most of the basin, which is supporting generally fair weather conditions. The exception is related to a weak upper trough over the Bahamas supporting a weak surface trough over eastern Cuba and scattered showers and a few thunderstorms over the southern coast of Cuba south of Camaguey, and another area of showers near Negril, in western Jamaica. Strong high pressure north of the area continues to support fresh to strong trade winds across the eastern and central Caribbean, as noted in recent buoy observations and scatterometer satellite data. Seas are reaching 8 to 12 ft, highest of Colombia in the area of developing gales. 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 N of the area by a 1042 mb high in the north central Atlantic and a 1039 mb high southwest of the Azores extends across the basin. The ridge is supporting moderate to fresh east to southeast flow over the western Atlantic west of 65W, with occasional fresh to strong trade winds south of 22N with 8 to 9 ft seas. A few showers are ongoing east of the central and northern Bahamas, related to surface trough reaching form the central Bahamas to eastern Cuba. A cold front will move off the northeast Florida coast by late Tue, followed by fresh northerly flow and building seas north of the Bahamas, then diminish through mid week as the front stalls and dissipates. Farther east over the central Atlantic, a nearly stationary upper low is centered near 25N45W, supporting a surface trough south of ridge along 45W from 20N to 28N. Scattered showers and thunderstorms are noted within 90 NM either side of the trough axis. The surface trough weakens the gradient enough to support mainly moderate to fresh trade wind flow across the central tropical Atlantic, but seas remain 8 to 10 ft in easterly swell. Over the eastern Atlantic, fresh to strong northeast winds persist north of 10N. The long duration and fetch of these strong winds support fully developed seas of 8 to 11 ft. Jet dynamics aloft on the southeast side of the upper low near 25N45W is supporting a broad area of multi-level cloudiness probably along with a few embedded showers from the coast of Guyana to the Cabo Verde Islands. For additional information please visit http://www.hurricanes.gov/marine $$ ERA/Christensen