000 AXNT20 KNHC 201755 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT APR 20 2013 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 1715 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS THE COAST OF LIBERIA NEAR 6N10W AND CONTINUES TO 3N15W. THE ITCZ BEGINS AT 3N16W AND CONTINUES ALONG 2N24W 3N37W 2N50W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 1N-5N BETWEEN 10W-30W. ISOLATED MODERATE CONVECTION IS FROM 2N-6N BETWEEN 33W AND 50W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...A COLD FRONT EXTENDS FROM THE SW N ATLC...ACROSS CENTRAL FLORIDA...THEN INTO THE SE GULF ALONG 26N82W 25N85W 21N89W AND ACROSS THE WESTERN YUCATAN PENINSULA. THIS COLD FRONT IS BEING SUPPORTED BY A BROAD UPPER LEVEL TROUGH THAT EXTENDS FROM THE UPPER STREAT LAKES TO N OF 24N IN THE GULF. MOST OF THE CONVECTION ASSOCIATED TO THIS FRONTAL BOUNDARY IS WEST OF THE FRONT N OF 26 E OF 86W BEING ENHANCED BY UPPER LEVEL DIVERGENCE. RADAR IMAGERY ALSO SHOW SCATTERED SHOWERS OVER THE FLORIDA KEYS. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE SOUTHERN GULF OF MEXICO EXTENDING FROM A CENTER W OF MEXICO WITH AXIS CONTINUING ACROSS THE YUCATAN PENINSULA TOWARDS THE NE BAHAMAS. SURFACE RIDGING HAS BUILT BEHIND THE COLD FRONT ANCHORED BY A 1025 MB HIGH OVER NORTHERN ALABAMA. N-NE WIND FLOW OF 20 KT DOMINATES THE BASIN W OF THE COLD FRONT...LIGHTER WINDS UP TO 15 KT ARE OVER THE WESTERN GULF W OF 92W. CLEAR SKIES ARE LIMITED TO THE FAR NW GULF N OF 24N W OF 90W. OVER THE NEXT 24 HOURS...THE FRONT IS EXPECTED TO DRIFT NE TOWARDS THE BAHAMAS WHILE A SURFACE TROUGH DEVELOPS OVER THE CENTRAL GULF. CARIBBEAN SEA... THE UPPER LEVEL RIDGE COVERING THE SOUTHERN GULF ALSO SPREADS OVER THE NW CARIBBEAN ACCOMPANIED BY DRY AIR ALOFT...WHICH IS PROVIDING FAIR SURFACE CONDITIONS N OF 14N W OF 69W. AN UPPER LEVEL TROUGH COVERS THE REMAINDER OF THE CARIBBEAN WITH AXIS EXTENDING FROM N OF PUERTO RICO TO COSTA RICA. MOIST SOUTHWESTERLY FLOW ALOFT COVERS THE EASTERN PORTIONS OF THE BASIN ENHANCING RAINSHOWERS/POSSIBLE THUNDERSTORMS OVER PUERTO RICO AND THE LESSER ANTILLES. TRADEWIND FLOW OF MAINLY 20 KT IS ACROSS THE CENTRAL AND EASTERN CARIBBEAN. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... A BROAD UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM THE UPPER STREAT LAKES TO N OF 24N IN THE GULF IS SUPPORTING A COLD FRONT OVER THE SW N ATLC ALONG 30N78W 28N80W...ACROSS CENTRAL FLORIDA INTO THE SE GULF. RAINSHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ASSOCIATED TO THE FRONT EXTEND W OF 75W N ACROSS THE WESTERN BAHAMAS. THE REMAINDER OF BOTH THE WEST AND CENTRAL ATLC ARE DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1033 MB HIGH NEAR 41N47W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 30N56W. A DISSIPATING STATIONARY FRONT EXTENDS IN THE NE PERIPHERY OF THE SURFACE RIDGE ALONG 30N39W 28N43W. AHEAD OF THIS FRONTAL BOUNDARY...AN UPPER TROUGH SUPPORTS A SURFACE TROUGH THAT EXTENDS ALONG 30N35W TO 23N38W. OVER THE E ATLC...A 1011 MB LOW IS LOCATED NEAR 27N18W WITH NO SHOWERS ASSOCIATED TO IT. THIS LOW IS EXPECTED TO DISSIPATE WITHIN THE NEXT 24 HOURS WHILE THE FRONT ENTERING THE W ATLC IS EXPECTED TO EXTEND OVER THE WESTERN BAHAMAS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR