000 AXNT20 KNHC 131139 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE AUG 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE CENTRAL TROPICAL WAVE EXTENDS FROM 19N35W THROUGH A 1010 MB LOW NEAR 12N35W TO 10N36W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY AND REMAINS WELL DEFINED IN THE UPPER LEVEL SATELLITE WINDS. NO ASSOCIATED SHOWERS OR DEEP CONVECTION. TROPICAL WAVE MOVING INTO THE E CARIBBEAN EXTENDS FROM 21N60W TO 11N61W MOVING W 20-25 KT. WATER VAPOR IMAGERY SHOWS THE WAVE TO THE E OF DRY STABLE AIR WITH THE TOTAL PRECIPITABLE WATER IMAGERY SHOWING THE WAVE IN AN AREA OF LIGHT TO MODERATE MOISTURE. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 13N-18N BETWEEN 60W-63W INCLUDING PORTIONS OF THE LESSER ANTILLES. TROPICAL WAVE IN THE CARIBBEAN EXTENDS FROM THE TURKS AND CAICOS NEAR 21N73W THROUGH THE WINDWARD PASSAGE TO 12N77W. AN AREA OF DEEP MOISTURE COVERS MOST OF THE CARIBBEAN AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 12N-18N BETWEEN 72W-77W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC OVER DAKAR SENEGAL AND CONTINUES ALONG 13N21W 13N32W THROUGH THE 1010 MB LOW NEAR 12N36W TO 8N42W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N48W 7N53W TO SOUTH AMERICA NEAR 6M58W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 10N-16N E OF 22W TO INLAND OVER AFRICA AND FROM 9N-13N BETWEEN 22W-32W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 6N-9N BETWEEN 34W-58W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE IS ANCHORED OVER W TEXAS EXTENDING AN AXIS E ACROSS THE SE CONUS TO GEORGIA COVERING THE NW GULF. A BROAD UPPER LOW CENTERED OVER N YUCATAN PENINSULA NEAR 21N89W COVERING THE REMAINDER OF THE GULF WITH A WEAK SURFACE TROUGH EXTENDING FROM 23N96W ACROSS THE BAY OF CAMPECHE TO S MEXICO JUST E OF COATZACOALCOS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 22N W OF THE TROUGH TO INLAND OVER MEXICO...S OF 27N BETWEEN 82W- 86W...AND S OF 24N BETWEEN 86W-91W INCLUDING THE YUCATAN CHANNEL. A SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS FLORIDA TO OVER THE GULF WITH A 1018 MB HIGH IN THE NE GULF NEAR 28N86W. THIS IS LEAVING THE REMAINDER OF THE GULF WITH FAIR CONDITIONS THIS MORNING. SURFACE RIDGE WILL PERSIST THROUGH WED. CARIBBEAN TROPICAL WAVE POSSIBLY ACCOMPANIED BY SURFACE LOW WILL MOVE INTO THE E GULF FROM THE NW CARIBBEAN LATE THU GRADUALLY APPROACHING THE NE GULF COAST SAT. CARIBBEAN SEA... THE UPPER LOW OVER THE S GULF OF MEXICO COVERS THE NW CARIBBEAN N OF 16N W OF 78W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 19N W OF 80W INCLUDING THE CAYMAN ISLANDS AND THE YUCATAN CHANNEL. A BROAD UPPER RIDGE DOMINATES THE REMAINDER OF THE CARIBBEAN ANCHORED OFF THE COAST OF COLOMBIA NEAR 15N73W. A BROAD 1009 MB SURFACE LOW IN THE SW CARIBBEAN NEAR 11N80W WITH THE MONSOON TROUGH EXTENDING FROM THE LOW ACROSS COSTA RICA NEAR 10N84W INTO THE E PACIFIC REGION. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE S OF 17N BETWEEN 77W-84W. THE REMAINDER OF THE ACTIVITY OVER THE CENTRAL CARIBBEAN AND THE LESSER ANTILLES ARE DUE TO THE TROPICAL WAVES. SEE ABOVE. CARIBBEAN TROPICAL WAVE WILL MOVE THROUGH THE W CARIBBEAN AND POSSIBLY MERGE WITH THE SURFACE LOW THROUGH WED NIGHT THEN MOVE NW OF THE AREA. THE TROPICAL WAVE MOVING ACROSS THE LESSER ANTILLES WILL DISSIPATE LATE TODAY. ANOTHER TROPICAL WAVE WILL ENTER E CARIBBEAN SAT. HISPANIOLA... SHOWERS/THUNDERSTORMS HAVE DISSIPATED OVER THE ISLAND THIS MORNING. TROPICAL WAVE IS W OF THE ISLAND IN THE WINDWARD PASSAGE. CHANCE OF AFTERNOON SHOWERS/THUNDERSTORMS WILL CONTINUE THROUGH TODAY WHEN THE CHANCE OF HEAVY PRECIPITATION WILL DECREASE AS NORTHERLY FLOW ALOFT MOVES OVER THE ISLAND LATER TODAY THROUGH SAT. AN INCREASE OF MOISTURE WILL THEN MOVE IN INCREASING THE POSSIBILITY OF HEAVIER SHOWERS/THUNDERSTORMS. ATLANTIC OCEAN... AN UPPER RIDGE COVERS THE W ATLC W OF 62W TO OVER N FLORIDA/ GEORGIA AND ANCHORED NEAR 32N71W. AN UPPER LOW IS IN THE W/CENTRAL ATLC NEAR 29N59W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 31N53W TO 24N57W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 25N-30N BETWEEN 54W-62W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 27N BETWEEN 62W- 66W. A BROAD SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC INTO THE GULF OF MEXICO WITH A WEAKNESS IN THE VICINITY OF THE ABOVE SURFACE TROUGH AND ANCHORED BY A 1025 MB HIGH NEAR 33N44W AND A 1024 MB HIGH W OF THE AZORES. GOES R INDICATES AN AREA OF DENSE SAHARAN DUST N OF 20N E OF 30W WITH A MODERATE SWATH WITHIN 150/175 NM OF LINE FROM 23N30W TO 14N5047W. SURFACE RIDGE WILL REMAIN IN PLACE THROUGH SAT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW