000 AXNT20 KNHC 130002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 PM EST Mon Feb 12 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 gradient between a strong surface ridge over the north Atlantic Ocean and lower pressure in northern South America will continue to support gale-force winds near the coast of Colombia. These conditions are expected continue through late this 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 axis enters the Atlantic through the coast of Liberia, Africa near 05N09W and continues to 01N18W where latest scatterometer data indicates the ITCZ begins and dips below the Equator at 20W. It resumes southwestward to the coast of Brazil near 05S36W. Scattered moderate convection is within 150 nm S of the axis between 09W-14W, and within 90 nm S of the axis between 14W-18W. ...DISCUSSION... GULF OF MEXICO... A cold front extends from the western panhandle of Florida to 27N90W, then stationary to the western Bay of Campeche. A pre- frontal trough is analyzed ahead of the stationary boundary. A ridge is across eastern Mexico and the NW Gulf behind the front. Strong northerly winds are south of 25N by the coast of Mexico. Moist southerly winds advecting northward over the gulf from the Caribbean in response to a mid to upper shortwave trough sliding eastward across the NE Gulf, are producing widespread showers in the northern gulf E of the trough. The front will weaken tonight with the frontal remnants lifting back N as a warm front on Tue. CARIBBEAN SEA... Please refer to the SPECIAL FEATURES section above for details about the gale-force winds expected near the coast of Colombia. The GOES-16 low to mid-level water vapor imagery shows generally dry and stable atmospheric conditions across the basin. Visible imagery depicts patches of shallow moisture advecting westward over much of the basin, including portions of Hispaniola. Brief passing isolated showers are with these clouds. A strong ridge N of the area anchored by a 1038 mb high center over the N central Atlantic extends across the northern half of the Caribbean, with the associated pressure gradient supporting the continuation of fresh to strong trade winds across the eastern and central basin as indicated by latest scatterometer data. Seas are in the range of 12 to 18 ft near the Colombia coast and 8 to 12 ft elsewhere. Fresh to near gale-force are also occurring through the Atlc passages and will continue through mid week. Otherwise, little change is expected through mid-week. ATLANTIC OCEAN... Broad surface high pressure over the area is associated with a 1038 mb high center over the N central Atlantic is supporting fresh to strong E-NE winds over most of the region, except close to the ridge axis north of 25N. An area of scattered showers and isolated thunderstorms is noted from 14N to 21N and between 45W and 60W in association with broad troughing that stretches from a cyclonic circulation just SW of the Canary Islands to 23N40W to 21N52W and as a shear axis to the northern Caribbean Sea. The shower activity should move across the Leeward Islands tonight through Tue night. A cold front is forecast to move off the northeast Florida coast by Tue morning. Scattered showers and thunderstorms are expected to develop ahead of the front and impact NW waters tonight into Tue as an upper level trough shifts eastward from the NE Gulf. The front will then stall and dissipate by Thu morning. The next cold front is forecast to enter the NW forecast waters by early Saturday morning. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell