000 AXNT20 KNHC 212341 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN APR 21 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 11N15W ALONG 4N20W TO 2N27W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 3N35W 3N47W TO INLAND OVER SOUTH AMERICA NEAR 2N51W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-6N BETWEEN 14W-27W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 6N TO THE EQUATOR BETWEEN 46W-51W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH EXTENDS FROM THE E CONUS INTO THE GULF NEAR THE ALABAMA/MISSISSIPPI BORDER TO 24N87W SUPPORTING A SURFACE TROUGH THAT AT 21/2100 UTC EXTENDS FROM 28N86W 24N89W TO INLAND OVER THE YUCATAN PENINSULA NEAR MERIDA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE E GULF FROM 23N-30N E OF THE SURFACE TROUGH TO INLAND OVER THE FLORIDA PENINSULA. SCATTERED LOW CLOUDS DOT MOST OF THE W GULF BUT WITH LIMITED SHOWER ACTIVITY. A BROAD SURFACE RIDGE IS N OF THE GULF WATERS ANCHORED OVER NEW ENGLAND. THE WEAK SURFACE TROUGH WILL LINGER THROUGH TUE AND SLOWLY DISSIPATE. A COLD FRONT IS EXPECTED TO MOVE INTO THE NW GULF WED WEAKEN AND STALL THU THEN DISSIPATE FRI. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS CENTRAL AMERICA INTO THE CARIBBEAN OVER NICARAGUA TO 14N77W. AN UPPER LOW IS E-NE OF PUERTO RICO EXTENDING A BROAD UPPER TROUGH OVER THE REMAINDER OF THE E CARIBBEAN. THE UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED TO HEAVY SHOWERS/SCATTERED THUNDERSTORMS INLAND OVER CUBA W OF 80W. AFTERNOON SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE DEVELOPING INLAND OVER HISPANIOLA AND JAMAICA. THE TRADE WINDS ARE ENHANCING SCATTERED SHOWERS GENERATED BY THE UPPER TROUGH OVER THE E CARIBBEAN FROM 12N-16N E OF 66W TO OVER THE LESSER ANTILLES. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES THIS EVENING. WINDS AND SEAS WILL DIMINISH THROUGH TUE NIGHT AS WEAK HIGH PRESSURE OVER THE W AND CENTRAL ATLC SHIFTS EAST. ATLANTIC OCEAN... A SHORTWAVE UPPER TROUGH EXTENDS FROM THE GEORGIA COAST S-SE TO 27N78W SUPPORTING A STATIONARY FRONT THAT EXTENDS INTO THE W ATLC AT 21/2100 UTC NEAR 32N73W TO 29N77W WHERE IT DISSIPATES TO 26N79W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE N OF 27N BETWEEN 73W-77W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS THAT HAVE DEVELOPED INLAND OVER FLORIDA AND PRODUCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 60/75 NM ALONG THE COAST OF FLORIDA AND THE UPPER FLORIDA KEYS. THE UPPER RIDGE OVER THE CARIBBEAN EXTENDS A RIDGE AXIS INTO THE W ATLC FROM E CUBA TO BEYOND 32N67W ENHANCING THE ACTIVITY ABOVE. AN UPPER LOW IS E-NE OF PUERTO RICO NEAR 20N62W EXTENDING A BROAD UPPER TROUGH OVER THE E CARIBBEAN AND GENERATING SCATTERED SHOWERS FROM 18N-21N BETWEEN 56W-61W. THE REMAINDER OF THE CENTRAL ATLC IS DOMINATED BY A BROAD UPPER RIDGE. A SURFACE RIDGE DOMINATES THE W AND CENTRAL ATLC W OF 50W TO THE STATIONARY FRONT ANCHORED WELL N OF THE DISCUSSION AREA. A BROAD UPPER TROUGH IS OVER E/CENTRAL AND E ATLC N OF 22N BETWEEN 30W-50W WITH THE UPPER LOW NEAR 27N40W AND SUPPORTING A 1010 MB SURFACE LOW NEAR 26N41W AND A SURFACE TROUGH THAT EXTENDS ALONG 25N38W 21N41W TO 20N47W. SCATTERED SHOWERS ARE FROM 25N-31N BETWEEN 35W-44W. A WEAK 1017 MB SURFACE HIGH IS W OF THE CANARY ISLANDS NEAR 27N24W. THE STATIONARY FRONT WILL WEAKEN INTO A SURFACE TROUGH MON THEN DRIFT SLOWLY E THROUGH THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW