000 AXNT20 KNHC 140519 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1219 AM EST WED DEC 14 2016 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 0500 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 05N09W to 05N12W. The Intertropical Convergence Zone axis extends from 05N12W to 06N18W to 03N40W. A surface trough is analyzed at the western extent of the ITCZ along 45W. Widely scattered moderate convection is from 02N-10N between 12W-36W. ...DISCUSSION... GULF OF MEXICO... Broad troughing aloft is noted over much of the eastern CONUS and Gulf basin this evening with water vapor imagery indicating a mid- level shortwave trough embedded within the overall flow in the vicinity of 31N87W. The shortwave supports a 1013 mb low centered across central Alabama with the associated cold front extending W-SW to near Galveston Texas. Pre-frontal surface troughing is also noted to the SE of the front from near Mobile Bay meandering SW to offshore of Corpus Christi Texas. Widely scattered showers and isolated tstms are occurring within 45 nm either side of the pre-frontal boundary remaining generally N of 28N. Otherwise... the remainder of the basin remains under the influence of surface ridging with axis extending from the Florida peninsula W-SW to the east-central coast of Mexico and the SW Gulf waters. Mostly clear skies prevail...however isolated shower and tstm activity is occurring across the eastern Bay of Campeche waters S of 21N E of 92W. Light to gentle anticyclonic winds are expected overnight into early Wednesday as the ridging continues to erode...however by Wednesday night the cold front along the coast will begin pushing E-SE through early Friday. Brief moderate to fresh N-NE winds are expected across the NW Gulf waters Thursday morning in wake of the front with the front shifting E of the basin entirely by early Friday. CARIBBEAN SEA... A broad upper level anticyclonic circulation is anchored over the eastern Caribbean near 15N64W with water vapor imagery indicating mostly dry air E of 77W and increased cloudiness and moisture W of 77W. As tropical moisture advects generally northward within the western periphery of the upper level ridging over the western Caribbean...widely scattered showers and isolated tstms are occurring mostly S of 21N between 81W-89W...including portions of Central America and the NW Caribbean waters. Farther east...mostly clear skies prevail with only a few quick-moving low-topped isolated showers occurring in the vicinity of the Windward islands and adjacent coastal waters of Hispaniola. Trades are expected to persist in the moderate to fresh range through the remainder of the week...increasing into fresh to strong levels Saturday as strong high pressure anchors to the north across the SW North Atlc waters. ...HISPANIOLA... Passing isolated showers are noted across the adjacent coastal waters associated with very shallow moisture. Moderate to fresh trade winds are also occurring across the island and the adjacent coastal waters. These conditions are expected through Saturday when surface high pressure will build north of the island and increase winds to fresh to strong breeze levels. ATLANTIC OCEAN... West-southwesterly flow aloft prevails over much of the SW North Atlc region this evening with mid-level shortwave energy noted on water vapor imagery progressing eastward over the SE CONUS. This troughing supports a weak area of low pressure focused on a 1013 mb low centered off the coast of the Carolinas near 34N75W with the associated cold front extending W across southern South Carolina and central Georgia. Surface ridging prevails to the south with axis extending from the central Atlc near 30N50W to the NW Bahamas and central Florida peninsula. Only a few isolated showers and tstms are noted N of 29N between 56W-72W on satellite imagery. Farther east...a surface ridge influences much of the remainder of the central and eastern Atlc anchored by a 1029 mb high centered near 34N31W. A weakening cold front extends into the discussion area near 32N18W SW to 26N36W and becomes diffuse to 25N50W. Isolated showers are possible within 90 nm either side of the front. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN