000 AXNT20 KNHC 131205 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 AM EST Tue Feb 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 1200 UTC surface analysis and satellite imagery through 1145 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 through Thu morning, then pulse to minimal gale each night into the weekend. Seas associated with these gale conditions are forecast to be 14 to 18 ft, subsiding some late in the 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 extends southwestward from the coast of Africa near 05N10W and crosses the equator near 19W. The ITCZ is located to the S of the equator. Scattered moderate isolated strong convection is within 60 nm S of the axis between 09W-12W. ...DISCUSSION... GULF OF MEXICO... A stationary front extends from just W of Apalachicola Florida to 27N91W, where it transitions to a warm front to 24N95W to 22N95W and becomes a stationary front again to inland the coast of Mexico near Coatzacoalcos. A trough is ahead of the frontal boundary from 23N92W to inland Mexico just W of Nuevo Progreso, while another trough extends from just W of the front near 25N95W northwestward to near Brownsville, Texas. Scattered showers and isolated thunderstorms are over portions of the NW and W central sections of the Gulf of Mexico. Similar activity is noted along and within 60 nm to the E of the trough that is ahead of the front. Isolated showers in very moist moderate to fresh E flow are over portions of the eastern gulf and Straits of Florida. High pressure W of the front is surging southward over the NW Gulf and across eastern Mexico. Strong northerly winds are S of 21N near the coast of Mexico. Moist southerly flow moving over the NE Gulf ahead of the front in response to a mid to upper level trough sliding eastward across the NE Gulf is producing widespread showers north of 25N east of the trough. The front will weaken today, with the frontal remnants slowly lifting back northward as a warm front through this evening. CARIBBEAN SEA... Please refer to the SPECIAL FEATURES section above for details about the gale-force winds expected near the coast of Colombia. Satellite water vapor imagery shows dry and stable atmospheric conditions across the basin. Patches of shallow trade wind showers, moving rather quickly westward, are advecting westward east of 75W, including the Lesser Antilles. A strong ridge N of the area anchored by a 1033 mb high over the central Atlc near 32N53W extends across the northern half of the Caribbean, with the associated pressure gradient supporting fresh to strong trade winds east of 80W. Seas are 14 to 18 ft near Colombia and 8 to 12 ft elsewhere. Strong winds are also occurring through the Atlc passages, and are expected to continue through at least Wed. ATLANTIC OCEAN... Broad surface high pressure over the area is associated with a 1033 mb centered over the N central Atlantic near 32N53W and moving southwestward is supporting fresh to strong E-NE winds over most of the region, except close to the ridge axis N of 25N. Isolated trade wind showers, moving quickly westward, are noted from 14N to 20N and to the W of 52W, including over much of the Leeward Islands. This shower activity will move across the Leeward Islands through late this afternoon or early this evening. Other isolated shower activity moving rapidly westward in moderate to fresh moist easterly flow are seen S of 26N and W of 57W. This activity is moving over the waters between the Bahamas and Cuba as well as across the Straits of Florida. A cold front along 31N and W of 76W as of 09Z will approach 30N Tue night, then become stationary across the central Atlantic Wed and Thu. Scattered showers and isolated thunderstorms along and within about 60 nm S of this frontal W of 77W will continue rather active through tonight as an upper level trough shifts eastward from the NE Gulf. The next cold front is forecast to move over the NW forecast waters by early on Sat morning. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell/Aguirre