000 AXNT20 KNHC 261756 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE APR 26 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...THE ITCZ... FROM THE COAST OF SOUTHERN LIBERIA NEAR 4N8W...CROSSING THE EQUATOR ALONG 17W...TO 6S25W...3S35W...INTO COASTAL NORTHEASTERN BRAZIL NEAR 1S47W. A BROAD AREA OF NUMEROUS MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS IS FROM 12S-4N BETWEEN 14W-40W. SCATTERED STRONG CONVECTION IS MOVING OFF THE COAST OF AFRICA BETWEEN 3W-12W. ...DISCUSSION... GULF OF MEXICO... FOR THIS EARLY AFTERNOON...MOSTLY DRY WESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY. THIS PATTERN IS SUPPRESSING ANY CONVECTIVE ACTIVITY AND MAINTAINING FAIR WEATHER CONDITIONS OVER THE GULF. HOWEVER...THE BASE OF AN UPPER LEVEL TROUGH MOVING ACROSS THE CENTRAL CONUS SUPPORTS AN AREA OF WEAK CONVECTION OVER THE FAR N CENTRAL BASIN. DOPPLER RADAR IMAGERY INDICATED A LINE OF MODERATE TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS MOVING ENE AT ABOUT 12 KT ALONG THE COAST OF LOUISIANA AND MISSISSIPPI BETWEEN 87W-90W. THIS LINE WILL CONTINUE TO WEAKEN THIS AFTERNOON. OTHERWISE...SSE WINDS UP TO 20 KT ARE OBSERVED ACROSS THE AREA. VISIBLE SATELLITE IMAGERY SHOWED AREAS OF LOW LEVEL STRATUS CLOUDS AND PATCHY FOG LINGERING OVER THE FAR NW BASIN. MARINE OBSERVATIONS IN THIS REGION INDICATED VISIBILITIES AS LOW AS 2 SM...ESPECIALLY NEAR THE COAST OF TEXAS. THESE CLOUDS ARE EXPECTED TO DISSIPATE OVER THE NEXT FEW HOURS. IN 24 HOURS A COLD FRONT IS EXPECTED TO EMERGE OFF THE TEXAS COAST WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. CARIBBEAN SEA... MOST OF THE CARIBBEAN SEA W OF 63W IS EXPERIENCING FAIR WEATHER CONDITIONS DUE TO DRY AND STABLE AIR ALOFT MOVING ACROSS THE AREA. AT SURFACE...SURFACE AND MARINE OBSERVATIONS INDICATE 15-20 KT TRADE WINDS TURNING N WESTWARD W OF 75W N OF 15N. THE OVERALL FLOW IS PUSHING SOME LOW LEVEL MOISTURE INLAND OVER WESTERN PANAMA AND COSTA RICA...GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS NEAR THE COAST BETWEEN 79W-84W. A SURFACE TROUGH IS MOVING OVER THE LESSER ANTILLES...ANALYZED FROM SAINT LUCIA TO VENEZUELA NEAR 10N62W. THIS SYSTEM IS GENERATING SCATTERED SHOWERS AND THUNDERSTORMS S OF DOMINICA E OF 63W. THE CONVECTION ASSOCIATED TO THIS SYSTEM HAS BECOME E TO W ELONGATED OVER THE PAST 6 HOURS. THEREFORE...THESE GROUP OF ISLANDS S OF 16N WILL CONTINUE TO EXPERIENCE CONVECTION FOR AT LEAST THE NEXT 24 HOURS AS THE TROUGH MOVES WEST AT ABOUT 15 KT. ATLANTIC OCEAN... MOST OF THE DISCUSSION AREA IS DOMINATED BY A STRONG UPPER LEVEL RIDGE COVERING THE ATLC W OF 33W. THIS UPPER RIDGE IS SUPPORTING A 1032 MB HIGH WOBBLING AROUND 33N57W. HOWEVER...A WEAKNESS IN THE RIDGE ASSOCIATED TO A WEAK MID/UPPER LEVEL TROUGH MOVING ACROSS THE WSW PERIPHERY OF THE RIDGE IS GENERATING AN AREA OF SCATTERED MODERATE TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 70 NM ON EITHER SIDE OF A LINE FROM 19N64W TO 24N70W TO 30N74W. SHORT RANGE COMPUTER MODELS SUGGEST THIS AREA OF CONVECTION WILL LINGER OVER THE NEXT 24 HOURS. SIMILAR ACTIVITY CAN BE FOUND OVER THE FAR W ATLC W OF 79W N OF FREEPORT IN THE BAHAMAS. A WEAK SURFACE TROUGH IS OVER THE TROPICAL ATLC ANALYZED FROM 13N53W TO 10N54W. THIS TROUGH IS ALSO RELATED TO A SECOND TROUGH CURRENTLY MOVING OVER THE LESSER ANTILLES. THESE TWO FEATURES ARE GENERATING SCATTERED SHOWERS AND THUNDERSTORMS W OF 50W FROM 11N-16N. THESE FEATURES WILL CONTINUE TO MOVE WESTWARD INTO THE CARIBBEAN BASIN OVER THE NEXT 24 HOURS. A WEAK LOW PRESSURE SYSTEM IS CAPTURE ON SATELLITE VISIBLE IMAGERY NEAR 30N30W. A WEAK COLD FRONT EXTENDS FROM THE LOW CENTER ALONG 30N27W TO 27N29W WITHOUT PRODUCING ANY SIGNIFICANT CONVECTION. ONLY A SMALL AREA OF SCATTERED SHOWERS IS NOTED FROM 30N-34N BETWEEN 24W-29W. THIS SYSTEM WILL CONTINUE TO WEAKEN OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA