000 AXNT20 KNHC 090007 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUL 08 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. ...SPECIAL FEATURES... AS OF 2100 UTC...TROPICAL STORM CHANTAL IS LOCATED NEAR 11.8N 53.9W ABOUT 340 NM E-SE OF BARBADOS. IT PRESENT MOVEMENT IS W-NW AT 23 KT AND IT HAS A MINIMUM CENTRAL PRESSURE OF 1005 MB. MAXIMUM SUSTAINED WINDS ARE NEAR 40 KT WITH HIGHER GUSTS. CHANTAL IS EXPECTED TO CONTINUE A W-NW TRACK FOR THE NEXT COUPLE OF DAYS AND THE CENTER OF CHANTAL SHOULD REACH THE LESSER ANTILLES EARLY TUESDAY...MOVE INTO THE EASTERN CARIBBEAN SEA LATER ON TUESDAY...AND BE NEAR THE DOMINICAN REPUBLIC ON WEDNESDAY. THE CENTER OF THE STORM IS WITHIN A CLUSTER OF MODERATE CONVECTION FROM 10N-14N BETWEEN 50W-57W. PLEASE READ THE LATEST PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT3/WTNT33 KNHC AND THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE EASTERN ATLC EXTENDING FROM 12N27W TO 04N27W MOVING W-SW NEAR 10 KT. THE WAVE IS EMBEDDED WITHIN A HIGH MOIST ENVIRONMENT WITHIN THE MONSOON TROUGH AXIS. SAL DRY AIR IS ENGULFING THIS WAVE AND CURRENTLY SPREADS OVER A PORTION OF THE WAVE AXIS N OF 10N. ISOLATED SHOWERS ARE WITHIN 80 NM OF THE AXIS S OF 09N. HOWEVER FURTHER WEST FROM 05N-09N BETWEEN 30W- 35W THERE IS A CLUSTER OF MODERATE CONVECTION THAT MIGHT BE ASSOCIATED WITH THIS WAVE. A TROPICAL WAVE IS OVER THE WESTERN CARIBBEAN EXTENDING FROM 25N77W TO 13N84W. THE PORTION OF THE WAVE AXIS OVER THE SW NORTH ATLC AND CUBA IS EMBEDDED WITHIN LOW MOIST ENVIRONMENT WHILE THE REMAINING AXIS IS OVER A MODERATE TO HIGH MOIST ENVIRONMENT. CONTINUOUS RAINSHOWERS AND THUNDERSTORMS HAVE BEEN REPORTED OVER EASTERN CUBA AS WELL AS NORTHERN NICARAGUA AND ACROSS HONDURAS. NE OF THE WAVE AXIS...TRAILING HIGH LOWER LEVELS MOISTURE FROM THE WAVE AS WELL AS UPPER LEVEL DIFFLUENCE FROM A CYCLONIC CIRCULATION NEAR 25N76W AND A BROAD RIDGE EXTENDING ACROSS MUCH OF THE CARIBBEAN IS SUPPORTING SCATTERED MODERATE CONVECTION AND THUNDERSTORMS FROM 21N-28N BETWEEN 69W-76W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR 11N15W TO 08N24W 06N32W 06N38W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 0N38W TO 0N49W. BESIDES THE CONVECTION ALREADY DISCUSSED ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION WITH EMBEDDED THUNDERSTORMS IS FROM 06N-15N E OF 23W. SCATTERED SHOWERS ARE WITHIN 130 NM S OF THE MONSOON TROUGH BETWEEN 21W-25W. ...DISCUSSION... GULF OF MEXICO... RETURN FLOW SPREADS ACROSS THE ENTIRE GULF THIS EVENING WITH WINDS RANGING FROM 10-15 KT. THIS ANTICYCLONIC FLOW HAS BEEN BANKING MODERATE TO HIGH LOWER LEVELS MOISTURE TO THE N-NW GULF COASTLINES WHICH IS ENHANCING RAINSHOWERS AND ISOLATED THUNDERSTORMS FROM THE FLORIDA PANHANDLE TO TAMPICO MEXICO. THESE SHOWERS EXTENDS ABOUT 60 NM OF THE COASTLINES ABOVE MENTIONED. SIMILAR CONVECTION LINGERS OVER THE CENTRAL GULF FROM 23N-27N BETWEEN 87W-93W. A SURFACE TROUGH EXTENDS ALONG THE WESTERN YUCATAN PENINSULA TO THE EASTERN BAY OF CAMPECHE E OF 92W. ISOLATED SHOWERS ARE POSSIBLE EAST OF THE ABOVE MENTIONED LONGITUDE IN THE BAY OF CAMPECHE. IN THE UPPER LEVELS A BROAD RIDGE COVERS THE BASIN AND NORTHERLY WIND AROUND ADVECTS MOISTURE TO THE BASIN WHICH IS SUPPORTING THE CONVECTION ABOVE MENTIONED. SURFACE RIDGING WILL CONTINUE ACROSS MUCH OF THE GULF WITHIN THE NEXT 48 HOURS WITH SOME TROUGHINESS LINGERING OVER THE BAY OF CAMPECHE. THE AXIS OF THE TROPICAL WAVE OVER THE WESTERN CARIBBEAN IS EXPECTED TO MOVE ACROSS THE FLORIDA PENINSULA TUESDAY EVENING AND MOVE ACROSS THE EASTERN GULF WEDNESDAY. RAINSHOWERS ACTIVITY WILL CONCENTRATE NW OF THE GULF ON TUESDAY AND OVER THE EASTERN GULF ON WEDNESDAY. CARIBBEAN SEA... A TROPICAL WAVE IS MOVING W-NW OVER THE WESTERN CARIBBEAN WITH AXIS EXTENDING FROM 25N77W TO 13N84W. CONTINUOUS RAINSHOWERS AND THUNDERSTORMS HAVE BEEN REPORTED OVER EASTERN CUBA AS WELL AS NORTHERN NICARAGUA AND ACROSS HONDURAS. TRAILING HIGH LOWER LEVELS MOISTURE FROM THE WAVE AS WELL AS UPPER LEVEL DIFFLUENCE FROM A CYCLONIC CIRCULATION NEAR 25N76W AND A BROAD RIDGE EXTENDING ACROSS MUCH OF THE CARIBBEAN IS SUPPORTING CONTINUOUS RAINSHOWERS AND THUNDERSTORMS ACROSS LA HISPANIOLA. OVER THE SOUTHERN CARIBBEAN SCATTERED MODERATE CONVECTION AND ISOLATED THUNDERSTORMS ARE OCCURRING S OF 12N WEST OF 79W. THIS CONVECTION IS ASSOCIATED WITH THE MONSOON TROUGH AXIS THAT MOVES ACROSS PANAMA. OTHERWISE...TRADEWINDS OF 15-20 KT SPREAD ACROSS THE BASIN. THE CENTER OF TROPICAL STORM CHANTAL IS EXPECTED TO MOVE ACROSS THE LESSER ANTILLES BY LATE TUESDAY MORNING AND SE OF DOMINICAN REPUBLIC WEDNESDAY AFTERNOON. NUMEROUS RAINSHOWERS ARE EXPECTED TO AFFECT THE EASTERN CARIBBEAN WITHIN THIS PERIOD. WINDS ARE EXPECTED TO INCREASE AT LEAST TO 25 KT OVER THE CENTRAL CARIBBEAN. SEE THE SPECIAL FEATURES SECTION FOR MORE INFORMATION REGARDING THIS LOW. HISPANIOLA... TRAILING HIGH LOWER LEVELS MOISTURE FROM THE WAVE CURRENTLY MOVING ACROSS WESTERN CUBA AS WELL AS UPPER LEVEL DIFFLUENCE FROM A CYCLONIC CIRCULATION NEAR 25N76W AND A BROAD RIDGE EXTENDING ACROSS MUCH OF THE CARIBBEAN IS SUPPORTING CONTINUOUS RAINSHOWERS AND THUNDERSTORMS ACROSS LA HISPANIOLA. WEATHER CONDITIONS IMPROVE BY TUESDAY BUT START TO DETERIORATE AGAIN EARLY ON WEDNESDAY AS TROPICAL CHANTAL MOVES SOUTH OF PUERTO RICO. CHANTAL IS EXPECTED TO MAKE LANDFALL INTO THE DOMINICAN REPUBLIC WEDNESDAY AFTERNOON. ATLANTIC OCEAN... TRAILING HIGH LOWER LEVELS MOISTURE FROM THE TROPICAL WAVE MOVING ACROSS THE WESTERN CARIBBEAN AS WELL AS UPPER LEVEL DIFFLUENCE FROM A CYCLONIC CIRCULATION NEAR 25N76W AND A BROAD RIDGE EXTENDING ACROSS MUCH OF THE CARIBBEAN IS SUPPORTING SCATTERED MODERATE CONVECTION AND THUNDERSTORMS FROM 21N-28N BETWEEN 69W-76W. A NARROW UPPER LEVEL TROUGH IS SUPPORTING A SURFACE TROUGH REMNANT OF A STATIONARY FRONT FROM 30N43W TO 27N51W 28N58W. ISOLATED SHOWERS ASSOCIATED TO IT ARE WITHIN 60 NM OF THE AXIS N OF 28N BETWEEN 43W-47W. EXCEPT FOR THE ATLC FEATURES ALREADY DISCUSSED...SURFACE RIDGING AND FAIR WEATHER DOMINATE THE REMAINDER ATLC WATERS. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2... FOR MORE DETAILS ABOUT TROPICAL STORM CHANTAL. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS