000 AXNT20 KNHC 111147 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 647 AM EST Thu Jan 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 0600 UTC surface analysis and satellite imagery through 1145 UTC. ...SPECIAL FEATURES... Strong surface high pressure will build across the central United States by this evening behind a cold front that will extend from the Great Lakes SW to eastern Texas to NE Mexico. The front is forecast to exit the coast of Texas overnight, then extending from the Florida Panhandle to the Yucatan Peninsula on Fri evening and move across the Straits of Florida on Sat evening. A strong pressure gradient between the ridge and the front will lead to the development of strong to gale-force northerly winds in the NW Gulf by late tonight, then extending to the SW Gulf on Friday. See the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the coast of Liberia, Africa near 06N10W to 02N20W to 01N30W. The ITCZ continues from 01N30W to 01S50W. Isolated rain showers are from 02S to 09N between 13W and 42W. ...DISCUSSION... GULF OF MEXICO... Broad surface high pressure over the NW Atlc waters extends a ridge axis SW across the SE CONUS and the NE Gulf of Mexico while weak surface low pressure dominates the remainder basin. This surface pattern is providing with light to moderate ESE flow E of 90W and light to fresh SE flow W of 90W...being the strongest winds near Veracruz, Mexico. GOES-16 water vapor imagery show generally deep layer dry air across the basin, which is hindering convection at this time. The next cold front is forecast to enter the NW basin late tonight along with strong to gale force winds that will extend to the SW basin through Friday evening. A reinforcing cold front will follow and move across Florida Sat. Strong northerly winds in the wake of the front will start to diminish early on Monday. See the special features section for further details on the front and the gale. CARIBBEAN SEA... Isolated showers cover most of the NW Caribbean waters. These showers are associated with a surface trough extending across western Cuba to 17N82W to NE Nicaragua adjacent waters, and middle to upper level diffluent flow. Hispaniola is underneath the upper level diffluent flow, which supports cloudiness and isolated showers across the island. Shallow moisture embedded in the tradewind flow support similar shower activity for eastern Puerto Rico, the USVI and adjacent waters. Otherwise, deep layer dry air support fair weather elsewhere. Moderate to fresh winds are across the central and eastern waters while light to gentle variable winds cover the western basin. Showers will continue in the NW Caribbean through today. The next cold front will enter the NW Caribbean late Friday night and extend from central Cuba SW to eastern Honduras Saturday night. ...HISPANIOLA... A broad area of diffluent flow aloft between an upper level low centered in the Great Bahama Bank and a ridge covering the eastern half of the Caribbean support overcast skies and isolated showers across most of the island. This activity is forecast to continue through tonight. ATLANTIC OCEAN... Scattered to isolated showers prevail over the SW N Atlc waters underneath a broad area of diffluent flow aloft. Showers across the northern Bahamas are also being supported by a surface trough along the Florida Peninsula. The tail of a cold front enters the north-central Atlc waters along 30N43W SW to 26N49W supporting scattered to isolated showers N of 26N between 38W and 47W. Otherwise, a broad surface ridge anchored by a 1032 mb high near 36N18W covers the entire Atlc N of 10N. The tail of a cold front will move further south over the NE Atlc waters by Friday night. The next cold front will come off NE Florida late Friday night with a reinforcing cold front following Sat night. The main cold front is forecast to extend from near 30N71W SW to eastern Cuba by Sunday night. For additional information please visit http://www.hurricanes.gov/marine $$ ERA