000 AXNT20 KNHC 292359 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAY 29 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W CONTINUING ALONG 11N17W TO 9N20W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N33W TO 5N48W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 90 NM EITHER SIDE OF THE ITCZ BETWEEN 23W-28W...FROM 4N-8N BETWEEN 30W-35W... WITHIN 120 NM N OF THE ITCZ BETWEEN 38W-45W...AND FROM 3N-8N BETWEEN 47W-52W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH IS DIGGING S FROM THE CENTRAL PLAIN STATES INTO MEXICO WHILE A SECOND UPPER TROUGH EXTENDS FROM THE COAST OF SOUTH CAROLINA ACROSS NE FLORIDA TO THE YUCATAN CHANNEL. THESE UPPER TROUGHS ARE AMPLIFYING AN UPPER RIDGE THAT EXTENDS FROM THE BAY OF CAMPECHE TO THE N GULF COAST NEAR THE ALABAMA/ MISSISSIPPI BORDER. A STRONG SURFACE RIDGE EXTENDS FROM THE W ATLC OVER THE SE CONUS GIVING THE GULF SE SURFACE FLOW. DRY STABLE AIR WITH STRONG SUBSIDENCE COVERS ALL BUT THE NW GULF. AN UPPER RIDGE IN THE W ATLC IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER FLORIDA AND CUBA EXTENDING OVER THE STRAITS OF FLORIDA E OF 84W. SIMILAR ACTIVITY IS MOVING INTO THE BAY OF CAMPECHE AHEAD OF TROPICAL STORM BARBARA THAT MADE LANDFALL AT 29/1950 UTC ALONG THE S COAST OF MEXICO ABOUT 20 MILES WEST OF TONALA. THE REMAINDER OF THE GULF IS UNDER WITH MOSTLY CLEAR SKIES THIS EVENING. THE SURFACE RIDGE WILL REMAIN IN PLACE THROUGH MON. A WEAK SURFACE TROUGH IS EXPECTED IN THE SW GULF FRI THROUGH SUN. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS FROM CENTRAL AMERICA NEAR THE TIP OF NICARAGUA/HONDURAS TO PUERTO RICO COVERING MOST OF THE CARIBBEAN. A WEAK UPPER TROUGH COVERS THE REMAINDER OF THE E CARIBBEAN. THE UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE NW CARIBBEAN N OF 16N BETWEEN 75W-86W INCLUDING CUBA AND JAMAICA. THE MONSOON TROUGH EXTENDS ALONG 11N/12N ACROSS THE SW CARIBBEAN FROM COLOMBIA TO OVER NICARAGUA WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 12N W OF 80W. EASTERLY TRADE WINDS ARE USHERING IN SOME SCATTERED LOW LEVEL SHOWERS OVER THE E CARIBBEAN N OF 12N E OF 74W ACROSS THE LESSER ANTILLES. THE W ATLC SURFACE RIDGE WILL MAINTAIN MODERATE TO FRESH TRADE WINDS ACROSS MUCH OF THE BASIN THROUGH MON. HISPANIOLA... CURRENTLY SCATTERED SHOWERS ARE OVER THE ENTIRE ISLAND WITH NUMEROUS THUNDERSTORMS SITTING OVER HAITI. THESE SHOWERS/ THUNDERSTORMS ARE MOVING WESTWARD INTO THE COASTAL WATERS OF HAITI. HISPANIOLA IS ALONG THE N PORTION OF THE UPPER RIDGE THAT COVERS MOST OF THE CARIBBEAN. THE ONAMET REPORTS THAT SHOWERS/ THUNDERSTORMS WILL CONTINUE TONIGHT BECOMING LESS INTENSE AND LESS FREQUENT ON THU. ATLANTIC OCEAN... THE UPPER TROUGH OVER FLORIDA AND THE E GULF OF MEXICO IS MOVING INTO THE W ATLC AND IS AMPLIFYING AN UPPER RIDGE THAT EXTENDS FROM HAITI TO BEYOND 32N72W. THIS UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 28N W OF 72W. BENIGN UPPER LEVEL FEATURES COVER THE REMAINDER OF THE ATLC BASIN. A WEAK SURFACE TROUGH EXTENDS FROM 31N51W TO 25N55W. A BROAD SURFACE RIDGE COVERS THE ENTIRE ATLC WITH A WEAKNESS IN THE VICINITY OF THE ABOVE SURFACE TROUGH. A 1030 MB HIGH IS IN THE W ATLC N OF BERMUDA WITH A 1033 MB HIGH IN THE E ATLC N OF THE AZORES. W ATLC RIDGE WILL PERSIST FROM N OF BERMUDA TO GEORGIA THROUGH MON. A LOW LEVEL TROUGHING ACROSS FLORIDA WILL REMAIN NEARLY STATIONARY BETWEEN FLORIDA AND THE BAHAMAS THROUGH SAT THEN DISSIPATE SUN. A WEAK SURFACE TROUGH IS EXPECTED TO DEVELOP NE OF THE BAHAMAS SUN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW