000 AXNT20 KNHC 141755 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 PM EST Tue Feb 14 2017 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 1745 UTC. ...SPECIAL FEATURES... ...Gulf of Mexico Gale... A strong cold front now emerging off the Texas coast is forecast to sweep eastward and extend from 30N86W to 21N95W to 18.5N95W by mid-morning Wed with NW to N winds increasing to 30-35 KT and seas building to 10 FT. This gale event is expected to be short- lived with winds diminishing below gale force by Wed evening. Please read the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...Southwest N Atlantic Gale... A cold front is forecast to sweep off the SE coast Wed evening. S to SW winds are forecast to increase to 30-35 KT and seas building to 10 FT N of 30N W of 78W by Wed afternoon. The cold front is expected to sweep rapidly east and extend from 31N72W to 26N81W by Thu morning with SW winds 30-35 KT continuing within 600 NM east of the front N of 29N. Please read the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 06N10W to 01N16W. The Intertropical Convergence Zone extends from 01N16W to 02N33W to the South American coast near 01N50W. Scattered moderate isolated strong convection was noted within 120-180 nm either side of the ITCZ between 25W and 44W. ...DISCUSSION... GULF OF MEXICO... A cold front has emerged off the Texas coast between Port O'Connor and just N of Brownsville as of 1500 UTC. A squall line was noted within 45 NM east of the front and currently extends from the Sabine River through 27.5N95.5W to 24.5N97W. WSR-88D regional mosaics indicated that the squall line was slowly weakening with time. Mostly fair conditions were noted elsewhere over the Gulf with light SSE winds east of 90W increasing to 20 KT west of 90W. The shortwave trough supporting the cold front was weakening with time as it was riding over a broad ridge in the Gulf. Moderate to strong subsidence was noted over the Gulf with some of the dry air entraining into the squall line and resulting in slow weakening with time. The cold front is forecast top move eastward across the Gulf over the next 24 to 48 hours with brief gale force winds S of 20N west of the cold front Wed afternoon. CARIBBEAN SEA... The pressure gradient across the Caribbean is weakening as the high pressure north of the region dissipates. This is resulting in a relaxing of the trade winds to gentle to moderate across the majority of the Caribbean, except over the south central Caribbean where moderate to fresh winds prevail. Isolated showers are observed over Hispaniola with a weakening frontal boundary that extends across the island from the north. Little change is expected over the next 24 hours. ...HISPANIOLA... Patches of broken to overcast low clouds with isolated showers are over the island due to a remnant low level frontal trough in the vicinity. The 12Z rawinsonde from San Juan Puerto Rico indicated a weak trade wind inversion, precipitable water values of 1.00 inch and light northerly winds up to 750 MB. Expect the showers to decrease in coverage over the next 24 hours as dry air spreads over the region. ATLANTIC OCEAN... A cold front enters the area of discussion near 31N55W and extends through 27N65W to 26N77W where it became stationary to the Florida east coast near Stuart near a small 1016 MB surface low. Widely scattered showers were noted along and within 90 NM east of the front mainly north of 27N. Further east, a series of surface troughs extended from 28N44W to the northeastern Windward Islands. A surface ridge prevails across the eastern Atlantic anchored by a stationary 1020 mb high centered near 21N33W. Over the next 24 hours, the surface high over the western Atlantic will dissipate while the cold front will continue moving east over the region. A new cold front will approach the southeast U.S. with S to SW winds increasing to gale force over the far northwest corner of the Atlantic. For additional information please visit http://www.hurricanes.gov/marine $$ Cobb