000 AXNT20 KNHC 210559 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1259 AM EST Tue Feb 21 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURES... A broad area of low pressure across the western North Atlc is forecast to strengthen during the next 24 to 36 hours and extend a cold front into the discussion area near 32N53W by 22/0000 UTC generating near gale to gale force SW winds N of 29N between 50N and 52W. The gale force conditions are expected to move N of the area by 23/0000 UTC. See 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 08N13W to 05N16W. The Intertropical Convergence Zone axis extends from 05N16W to 02N21W to the Equator near 28W. Scattered moderate convection is S of 05N between 25W-33W. ...DISCUSSION... GULF OF MEXICO... A sharp middle to upper level trough is noted on water vapor imagery over the central CONUS with trough axis dipping southward over the extreme western Gulf waters and NE Mexico. The troughing supports a 1012 mb low centered along the central Louisiana coast near 30N92W with a surface trough extending S-SW to 23N95W. Scattered showers and widely scattered tstms are occurring N of 24N between 90W-95W largely enhanced by strong middle to upper level diffluence. Otherwise...the eastern half of the basin is under the influence of a surface ridge anchored by a 1025 mb high centered across the Carolinas this evening. Mostly clear skies prevail across the Florida peninsula...however middle to upper level cloudiness and moisture is noted W of 85W as the upper level trough approaches from the west. Looking ahead...the surface trough is forecast to move into the eastern Gulf by late Tuesday night into Wednesday. A secondary boundary...currently a cold front analyzed across western Oklahoma and Texas...is expected to emerge off the Texas and Louisiana coasts Tuesday and quickly merge with the surface troughing lingering across the eastern Gulf. As this occurs...a broad area of low pressure is forecast to develop on Wednesday across the NE Gulf waters and drift eastward across the Florida peninsula into the SW North Atlc waters by Friday into Friday night. CARIBBEAN SEA... Overall the Caribbean basin remains under fairly tranquil conditions this evening with the exception of the northeastern waters. An area of low pressure well N of Puerto Rico extends a cold front along 65W to 22N then SW to the northern coast of Hispaniola near 20N70W. Low-level moisture convergence within southerly winds is generating widely scattered showers and isolated tstms N of 13N between 59W-69W...including portions of the Lesser Antilles...Puerto Rico...and the Mona Passage region. Otherwise...dry and stable air aloft coupled with gentle to moderate E-NE winds are prevailing and expected to persist through Tuesday night. By Wednesday...a cold front is expected to move across the central Gulf of Mexico and reach the Yucatan Channel region and NW Caribbean waters introducing another round of fresh to occasional strong W-NW winds. ...HISPANIOLA... Isolated showers are expected during the overnight hours into Tuesday as a cold front is analyzed to the NE of the island. Persistent northerly winds will continue to feed Atlc moisture across northern portions of the islands that will result in these showers through Wednesday afternoon. ATLANTIC OCEAN... A broad area of low pressure is noted across the SW North Atlc focused on a 1011 mb low centered near 28N66W. The associated cold front extends S to 22N65W then SW to the northern coast of Hispaniola near 20N70W. Scattered showers and tstms are occurring to the E of the low from 18N-27N between 55W-63W. The low is forecast to continue moving eastward and merge with a cold front dropping into the discussion area from the NW...currently analyzed from Bermuda near 32N65W to 30N70W. The entire system will move into the central Atlc waters by Tuesday night into Wednesday producing the Special Features near gale to gale force conditions mentioned above. Otherwise...the remainder of the SW North Atlc is under the influence of a surface ridge anchored by a 1025 mb high centered across the Carolinas. The ridge will slide offshore through Wednesday. Finally...the remainder of the eastern Atlc is under the influence of another surface ridge anchored by a 1033 mb high centered NE of the Azores near 44W19W. The ridge axis extends SW from the high to 32N32N to 16N47W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN