000 AXNT20 KNHC 130548 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED JUL 13 2011 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 0500 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE ERN TRPCL ATLC IS ALONG 16N27W TO 10N31W MOVING W 10-15 KT. WAVE IS LOW AMPLITUDE...BUT CYCLONIC FLOW AROUND THE AXIS IS INDICATED IN SATELLITE DERIVED WINDS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE JUST E OF THE LESSER ANTILLES EXTENDS FROM NEAR 18N59W TO 8N62W MOVING W 10-15 KT. WAVE CONTINUES TO PRECEDE A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. A CLUSTER OF STRONG CONVECTION IS FROM 17N-20N BETWEEN 54W-57W. ISOLATED MODERATE CONVECTION IS WITHIN 75 NM EITHER SIDE OF THE AXIS. TROPICAL WAVE JUST E OF THE YUCATAN PENINSULA EXTENDS ALONG 21N87W TO 14N88W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE NW CARIBBEAN AND SW GULF OF MEXICO. BASED ON THE AREA OF MAXIMUM MOISTURE AND CYCLONIC FLOW EVIDENT IN SATELLITE IMAGERY...THE WAVE APPEARS TO HAVE SPED UP AND BE FARTHER W THAN CURRENTLY DEPICTED. THE WAVE WILL LIKELY BE RELOCATED ON THE NEXT ANALYSIS. THE WAVE CONTINUES TO LIE UNDER DIFFLUENT FLOW ALOFT WHICH IS HELPING ENHANCE CONVECTION. SCATTERED MODERATE/STRONG CONVECTION IS FROM 17N-22N BETWEEN 91W-95W...AND FROM 14N-17N BETWEEN 88W-90W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 24N ALONG 22N15W 12N21W 8N37W. THE ITCZ CONTINUES FROM 8N37W TO 6N54W. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM S OF THE AXIS BETWEEN 22W-43W. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE JUST E OF THE YUCATAN PENINSULA IS CAUSING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE BAY OF CAMPECHE S OF 22N BETWEEN 90W-95W. WEAK SURFACE RIDGING ALONG 25N COVERS THE REMAINDER OF THE GULF OF MEXICO EXTENDING FROM THE ATLC SUPPORTING FAIR WEATHER AND LIGHT ANTI-CYCLONIC FLOW AROUND THE RIDGE. A FEW ISOLATED SHOWERS...REMNANTS OF AFTERNOON CONVECTION...ARE ACROSS THE NE GULF FROM 28N-30N BETWEEN 85W-90W. ALOFT...AN UPPER LEVEL RIDGE COVERS THE NRN GULF CENTERED OVER CENTRAL ALABAMA. AN INVERTED UPPER LEVEL TROUGH COVERS THE SW GULF WITH AXIS FROM 18N98W TO 28N93W. WATER VAPOR IMAGERY INDICATES DRY AIR IS WRAPPING AROUND THE SRN EXTENT OF THE UPPER RIDGE WHICH IS FURTHER SUPPORTING THE FAIR WEATHER. TOTAL PRECIPITABLE WATER IMAGERY STILL INDICATES ENHANCED MOISTURE IS ACROSS THE NRN GULF. WITH DAYTIME HEATING THIS WILL LIKELY MEAN SHOWERS/THUNDERSTORMS WILL POP UP LATER IN THE AFTERNOON TODAY. SHOWER/THUNDERSTORM ACTIVITY WILL ALSO CONTINUE IN THE SW GULF AS THE TROPICAL WAVE MOVES WWD. WEAK SURFACE RIDGING WILL CONTINUE OVER THE NRN GULF. CARIBBEAN SEA... THE NW CARIBBEAN IS CURRENTLY UNDER FAIR CONDITIONS AS MOISTURE ASSOCIATED WITH A TROPICAL WAVE JUST E OF THE YUCATAN PENINSULA HAS MOVED MAINLY INTO THE SW GULF OF MEXICO. THE SW CARIBBEAN REMAINS UNDER MOIST CONDITIONS INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS CENTRAL NICARAGUA TO NRN COLOMBIA. A CLUSTER OF STRONG SHOWERS/THUNDERSTORMS IS CURRENTLY FROM 10N-12N BETWEEN 75W-79W...AND INLAND OVER COLOMBIA FROM 4N-11N BETWEEN 71W-76W. ISOLATED SHOWERS/THUNDERSTORMS COVER THE REMAINDER OF THE AREA S OF 14N BETWEEN 73W-84W. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS HISPANIOLA WITH ISOLATED ACTIVITY OVER PUERTO RICO. THIS ACTIVITY IS GENERATED BY THE COMBINATION OF ENHANCED MOISTURE ACROSS THIS AREA EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY ALONG WITH DIFFLUENCE ALOFT AROUND AN UPPER LEVEL TROUGH CENTERED NEAR 16N75W. ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE ALSO ACROSS THE WINDWARD ISLANDS DUE TO AN APPROACHING TROPICAL WAVE JUST E OF THE ISLANDS. EXPECT SHOWER/THUNDERSTORM ACTIVITY TO PERSIST ACROSS THE WINDWARD ISLANDS DUE TO THE WAVE...AS WELL AS ACROSS THE N CENTRAL ISLANDS. ALSO...MUCH OF CENTRAL AMERICA AND SRN MEXICO IS AT THREAT FOR PROLONGED HEAVY RAINFALL THROUGHOUT THE END OF THE WEEK WHICH WILL INCREASE THE CHANCE FOR DEADLY FLOODING AND MUDSLIDES. MODEL GUIDANCE INDICATES THE MONSOON TROUGH WILL CONTINUE TO LIFT FARTHER N PLACING ABNORMALLY STRONG WLY FLOW AGAINST CENTRAL AMERICA AND SRN MEXICO. THIS W-SW FLOW WILL DRAW SIGNIFICANT TROPICAL MOISTURE ACROSS THESE AREAS. COMBINED WITH OROGRAPHIC LIFT DUE TO MOUNTAINS THIS CREATES A FORMULA TO EQUAL HEAVY PRECIPITATION. THESE AREAS SHOULD MONITOR THE SITUATION OVER THE NEXT FEW DAYS AND STAY TUNED FOR UPDATES ON THIS POSSIBLY DANGEROUS SCENARIO. ATLANTIC OCEAN... SURFACE RIDGING DOMINATES THE MAJORITY OF THE ATLC ANCHORED BY A 1031 MB AZORES HIGH NEAR 41N27W PROVIDING FAIR CONDITIONS BASIN-WIDE. ALOFT...AN UPPER LEVEL RIDGE COVERS THE WRN ATLC CENTERED OVER CENTRAL ALABAMA. AN UPPER LEVEL TROUGH IS TO THE E ALONG 51W. A SHORTWAVE UPPER TROUGH EXTENDS OFF THE MAIN TROUGH EXTENDING TO THE CENTRAL BAHAMAS. THIS IS PRODUCING SOME UPPER LEVEL CLOUDS AND ISOLATED SHOWERS FROM 25N-32N BETWEEN 52W-60W. UPPER LEVEL RIDGING COVERS MUCH OF THE ERN ATLC CENTERED NEAR 35N32W. AN UPPER LEVEL TROUGH COVERS THE FAR ERN ATLC CENTERED OVER THE MADEIRA ISLANDS. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL LOW IS CENTERED NEAR 25N38W...AND AN UPPER LEVEL RIDGE IS CENTERED OFF THE W COAST OF AFRICA NEAR 20N24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 130548 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED JUL 13 2011 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 0500 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE ERN TRPCL ATLC IS ALONG 16N27W TO 10N31W MOVING W 10-15 KT. WAVE IS LOW AMPLITUDE...BUT CYCLONIC FLOW AROUND THE AXIS IS INDICATED IN SATELLITE DERIVED WINDS. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE JUST E OF THE LESSER ANTILLES EXTENDS FROM NEAR 18N59W TO 8N62W MOVING W 10-15 KT. WAVE CONTINUES TO PRECEDE A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. A CLUSTER OF STRONG CONVECTION IS FROM 17N-20N BETWEEN 54W-57W. ISOLATED MODERATE CONVECTION IS WITHIN 75 NM EITHER SIDE OF THE AXIS. TROPICAL WAVE JUST E OF THE YUCATAN PENINSULA EXTENDS ALONG 21N87W TO 14N88W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE NW CARIBBEAN AND SW GULF OF MEXICO. BASED ON THE AREA OF MAXIMUM MOISTURE AND CYCLONIC FLOW EVIDENT IN SATELLITE IMAGERY...THE WAVE APPEARS TO HAVE SPED UP AND BE FARTHER W THAN CURRENTLY DEPICTED. THE WAVE WILL LIKELY BE RELOCATED ON THE NEXT ANALYSIS. THE WAVE CONTINUES TO LIE UNDER DIFFLUENT FLOW ALOFT WHICH IS HELPING ENHANCE CONVECTION. SCATTERED MODERATE/STRONG CONVECTION IS FROM 17N-22N BETWEEN 91W-95W...AND FROM 14N-17N BETWEEN 88W-90W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 24N ALONG 22N15W 12N21W 8N37W. THE ITCZ CONTINUES FROM 8N37W TO 6N54W. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM S OF THE AXIS BETWEEN 22W-43W. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE JUST E OF THE YUCATAN PENINSULA IS CAUSING SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE BAY OF CAMPECHE S OF 22N BETWEEN 90W-95W. WEAK SURFACE RIDGING ALONG 25N COVERS THE REMAINDER OF THE GULF OF MEXICO EXTENDING FROM THE ATLC SUPPORTING FAIR WEATHER AND LIGHT ANTI-CYCLONIC FLOW AROUND THE RIDGE. A FEW ISOLATED SHOWERS...REMNANTS OF AFTERNOON CONVECTION...ARE ACROSS THE NE GULF FROM 28N-30N BETWEEN 85W-90W. ALOFT...AN UPPER LEVEL RIDGE COVERS THE NRN GULF CENTERED OVER CENTRAL ALABAMA. AN INVERTED UPPER LEVEL TROUGH COVERS THE SW GULF WITH AXIS FROM 18N98W TO 28N93W. WATER VAPOR IMAGERY INDICATES DRY AIR IS WRAPPING AROUND THE SRN EXTENT OF THE UPPER RIDGE WHICH IS FURTHER SUPPORTING THE FAIR WEATHER. TOTAL PRECIPITABLE WATER IMAGERY STILL INDICATES ENHANCED MOISTURE IS ACROSS THE NRN GULF. WITH DAYTIME HEATING THIS WILL LIKELY MEAN SHOWERS/THUNDERSTORMS WILL POP UP LATER IN THE AFTERNOON TODAY. SHOWER/THUNDERSTORM ACTIVITY WILL ALSO CONTINUE IN THE SW GULF AS THE TROPICAL WAVE MOVES WWD. WEAK SURFACE RIDGING WILL CONTINUE OVER THE NRN GULF. CARIBBEAN SEA... THE NW CARIBBEAN IS CURRENTLY UNDER FAIR CONDITIONS AS MOISTURE ASSOCIATED WITH A TROPICAL WAVE JUST E OF THE YUCATAN PENINSULA HAS MOVED MAINLY INTO THE SW GULF OF MEXICO. THE SW CARIBBEAN REMAINS UNDER MOIST CONDITIONS INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS CENTRAL NICARAGUA TO NRN COLOMBIA. A CLUSTER OF STRONG SHOWERS/THUNDERSTORMS IS CURRENTLY FROM 10N-12N BETWEEN 75W-79W...AND INLAND OVER COLOMBIA FROM 4N-11N BETWEEN 71W-76W. ISOLATED SHOWERS/THUNDERSTORMS COVER THE REMAINDER OF THE AREA S OF 14N BETWEEN 73W-84W. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS HISPANIOLA WITH ISOLATED ACTIVITY OVER PUERTO RICO. THIS ACTIVITY IS GENERATED BY THE COMBINATION OF ENHANCED MOISTURE ACROSS THIS AREA EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY ALONG WITH DIFFLUENCE ALOFT AROUND AN UPPER LEVEL TROUGH CENTERED NEAR 16N75W. ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS ARE ALSO ACROSS THE WINDWARD ISLANDS DUE TO AN APPROACHING TROPICAL WAVE JUST E OF THE ISLANDS. EXPECT SHOWER/THUNDERSTORM ACTIVITY TO PERSIST ACROSS THE WINDWARD ISLANDS DUE TO THE WAVE...AS WELL AS ACROSS THE N CENTRAL ISLANDS. ALSO...MUCH OF CENTRAL AMERICA AND SRN MEXICO IS AT THREAT FOR PROLONGED HEAVY RAINFALL THROUGHOUT THE END OF THE WEEK WHICH WILL INCREASE THE CHANCE FOR DEADLY FLOODING AND MUDSLIDES. MODEL GUIDANCE INDICATES THE MONSOON TROUGH WILL CONTINUE TO LIFT FARTHER N PLACING ABNORMALLY STRONG WLY FLOW AGAINST CENTRAL AMERICA AND SRN MEXICO. THIS W-SW FLOW WILL DRAW SIGNIFICANT TROPICAL MOISTURE ACROSS THESE AREAS. COMBINED WITH OROGRAPHIC LIFT DUE TO MOUNTAINS THIS CREATES A FORMULA TO EQUAL HEAVY PRECIPITATION. THESE AREAS SHOULD MONITOR THE SITUATION OVER THE NEXT FEW DAYS AND STAY TUNED FOR UPDATES ON THIS POSSIBLY DANGEROUS SCENARIO. ATLANTIC OCEAN... SURFACE RIDGING DOMINATES THE MAJORITY OF THE ATLC ANCHORED BY A 1031 MB AZORES HIGH NEAR 41N27W PROVIDING FAIR CONDITIONS BASIN-WIDE. ALOFT...AN UPPER LEVEL RIDGE COVERS THE WRN ATLC CENTERED OVER CENTRAL ALABAMA. AN UPPER LEVEL TROUGH IS TO THE E ALONG 51W. A SHORTWAVE UPPER TROUGH EXTENDS OFF THE MAIN TROUGH EXTENDING TO THE CENTRAL BAHAMAS. THIS IS PRODUCING SOME UPPER LEVEL CLOUDS AND ISOLATED SHOWERS FROM 25N-32N BETWEEN 52W-60W. UPPER LEVEL RIDGING COVERS MUCH OF THE ERN ATLC CENTERED NEAR 35N32W. AN UPPER LEVEL TROUGH COVERS THE FAR ERN ATLC CENTERED OVER THE MADEIRA ISLANDS. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL LOW IS CENTERED NEAR 25N38W...AND AN UPPER LEVEL RIDGE IS CENTERED OFF THE W COAST OF AFRICA NEAR 20N24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON