000 AXNT20 KNHC 010537 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 01 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE OVER THE W CARIBBEAN EXTENDS FROM 23N84W TO 15N83W MOVING W 15-20 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE THAT COVERS THE NW CARIBBEAN AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER...THE WAVE IS BECOMING LESS DEFINED WITH NO ASSOCIATED DEEP CONVECTION. THE ACTIVITY IN THE VICINITY IS DUE TO UPPER LEVEL FEATURES RATHER THAN THE TROPICAL WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 21N17W AND CONTINUES THROUGH A WEAK 1011 MB LOW NEAR 18N21W THEN ALONG 10N31W TO 7N40W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 5N47W TO SOUTH AMERICA NEAR 5N53W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120/150 NM ALONG THE COAST OF W AFRICA BETWEEN THE GUINEA/GUINEA BISSAU BORDER TO DAKAR SENEGAL. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE ANCHORED OVER CENTRAL TEXAS EXTENDS SE ACROSS THE GULF TO W CUBA GIVING THE GULF N TO E FLOW ALOFT. A SHORTWAVE UPPER TROUGH EXTENDS ALONG THE COAST FROM NEAR CHARLESTON SOUTH CAROLINA OVER JACKSONVILLE FLORIDA TO NEAR GAINESVILLE FLORIDA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 60 NM ALONG THE COAST OF FLORIDA N OF TAMPA E OF PANAMA CITY. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THE DEEP MOISTURE THAT COVERS THE NW CARIBBEAN EXTENDS N OVER THE E GULF OF MEXICO AND THE BAY OF CAMPECHE PROVIDING THE MOISTURE LADEN ENVIRONMENT FOR THE EASTERLY UPPER FLOW AND EASTERLY SURFACE FLOW TO COMBINE AND GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 26N E OF 84W...S OF 24N BETWEEN 84W-90W...AND S OF 21N BETWEEN 93W-96W IN THE BAY OF CAMPECHE. THE SURFACE RIDGE ANCHORED IN THE ATLC EXTENDS ACROSS FLORIDA TO TEXAS AND NE MEXICO WITH A PAIR OF WEAK 1018 MB HIGHS NEAR 29N84W AND 28N92W. WEAK SURFACE RIDGE WILL REMAIN STATIONARY THROUGH FRI THEN DRIFT IN SLIGHTLY S SAT THROUGH MON. THE NORTHERN PORTION OF THE WEAK CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE SE GULF TONIGHT AND INTO THU AS IT WEAKENS. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO CLIPS THE FAR NW CARIBBEAN N OF 18N W OF 81W. A SECOND UPPER RIDGE COVERS THE SW CARIBBEAN S OF 16N W OF 77W INDUCING AN UPPER TROUGH THAT EXTENDS FROM NEAR JAMAICA TO OVER THE GULF OF HONDURAS. THE UPPER LOW CENTERED OVER THE CENTRAL BAHAMAS DIPS S OVER THE N/CENTRAL CARIBBEAN TO 18N BETWEEN THE WINDWARD PASSAGE AND 81W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 18N TO OVER CUBA BETWEEN 75W-86W. A WEAK UPPER LOW IS OVER THE VIRGIN ISLANDS LEAVING HISPANIOLA IN A CULL AREA BETWEEN THE UPPER LOWS. ISOLATED SHOWERS ARE OVER THE NE CARIBBEAN N OF 16N E OF THE MONA PASSAGE TO OVER THE LEEWARD ISLANDS. WATER VAPOR IMAGERY INDICATES DRY STABLE AIR ALOFT DOMINATES MOST OF THE CARIBBEAN E OF 77W. THE MONSOON TROUGH EXTENDS ALONG 9N/10N FROM COLOMBIA TO COSTA RICA ARE GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF 10N E OF 78W AND S OF 13N W OF 78W. THE WEAK TROPICAL WAVE WILL ENTER THE SE GULF OF MEXICO TONIGHT AND THU. A TIGHT PRESSURE GRADIENT WILL CONTINUE TO RESULT IN FRESH TO STRONG TRADE WINDS ACROSS MUCH OF THE S/CENTRAL CARIBBEAN THROUGH THE MON. HISPANIOLA... THE AFTERNOON SHOWERS/THUNDERSTORMS HAVE DIMINISHED AND SKIES HAVE CLEARED ACROSS THE ENTIRE ISLAND WITH SOME LINGERING HIGH CLOUDS OVER PORTIONS OF HAITI AND SW DOMINICAN REPUBLIC. HISPANIOLA IS IN A CULL AREA BETWEEN AN UPPER LOW CENTERED OVER THE CENTRAL BAHAMAS AND A SECOND CENTERED OVER THE VIRGIN ISLANDS. THIS WEAK SECOND UPPER LOW WILL BE ABSORBED BY A BROAD UPPER LOW IN THE CENTRAL ATLC AND WILL SHIFT W TO OVER HISPANIOLA EARLY THE WEEKEND INCREASING PRECIPITATION OVER THE ISLAND. AFTERNOON SHOWERS AND THUNDERSTORMS ARE STILL POSSIBLE OVER THE NEXT FEW DAYS. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS A RIDGE AXIS ACROSS FLORIDA NEAR DAYTONA BEACH TO BEYOND 32N71W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS NW OF LINE FROM DAYTONA BEACH FLORIDA TO BEYOND 32N77W. AN UPPER LOW IS TO THE S CENTERED OVER THE CENTRAL BAHAMAS NEAR 24N77W AND EXTENDS S OVER CUBA SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 26N73W TO 21N74W GENERATING SCATTERED SHOWERS/THUNDERSTORMS FROM 22N-24N BETWEEN 74W-77W WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 26N-29N BETWEEN 72W-77W. A REMNANT SURFACE TROUGH EXTENDS FROM 32N60W ALONG 30N63W TO 28N66W GENERATING ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS 90 NM EITHER SIDE OF THE TROUGH. A SECOND LARGER UPPER LOW IS IN THE CENTRAL ATLC NEAR 26N54W GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM 33N52W TO 28N58W. A VERY BROAD UPPER TROUGH OVER THE NE ATLC DIPS S TO 27N E OF 35W SUPPORTING A COLD FRONT THAT EXTENDS INTO THE DISCUSSION AREA NEAR 32N24W TO 31N30W THEN NW TO BEYOND 32N38W. WATER VAPOR IMAGERY INDICATES THIS IS A DRY STABLE AREA...THUS NO ASSOCIATED ACTIVITY. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE...WITH A WEAKNESS IN THE IMMEDIATE VICINITY OF THE ABOVE COLD FRONT AND IS ANCHORED BY A 1029 MB NW OF THE AZORES AND A WEAKER 1025 MB HIGH NEAR 31N44W. SURFACE RIDGE WILL REMAIN NEARLY STATIONARY THROUGH THU NIGHT THEN SHIFT S TO NEAR 27N FRI THROUGH MON. A WEAK TROUGH OVER THE SE BAHAMAS WILL MOVE NW THROUGH THU NIGHT AND N FRI WHILE DISSIPATING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW