000 AXNT20 KNHC 131116 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1100 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE ERN TRPCL ATLC IS ALONG 15N28W 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 ACROSS THE LESSER ANTILLES EXTENDS FROM NEAR 19N59W TO 10N63W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 13N-18N BETWEEN 58W-62W...AND FROM 13N-15N BETWEEN 62W-66W. TROPICAL WAVE PREVIOUSLY E OF THE YUCATAN PENINSULA HAS BEEN RELOCATED FARTHER W AND NOW EXTENDS ALONG 22N92W TO 15N92W MOVING W 15-20 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE SW GULF OF MEXICO. THE WAVE CONTINUES TO LIE UNDER DIFFLUENT FLOW ALOFT WHICH IS HELPING ENHANCE CONVECTION. SCATTERED MODERATE/STRONG CONVECTION IS FROM 15N-22N BETWEEN 93W-95W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 21N ALONG 17N14W 11N22W 8N35W. ITCZ CONTINUES FROM 8N35W TO 5N56W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 12W-15W...AND FROM 7N-9N BETWEEN 27W-32W. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE IN THE BAY OF CAMPECHE IS CAUSING SCATTERED SHOWERS/THUNDERSTORMS S OF 24N BETWEEN 92W-98W. 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 AXIS. A FEW ISOLATED SHOWERS THUNDERSTORMS ARE NOTED ACROSS THE NRN GULF N OF 26N BETWEEN 83W-93W WHERE ENHANCED MOISTURE VALUES ARE INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. ALOFT...AN UPPER LEVEL RIDGE COVERS THE NRN GULF CENTERED OVER CENTRAL ALABAMA. AN INVERTED UPPER LEVEL TROUGH COVERS THE FAR SW GULF WITH AXIS OVER MEXICO. A WEAK AND NARROW UPPER RIDGE IS TO THE E EXTENDING ACROSS THE YUCATAN PENINSULA. THIS PATTERN IS CREATING DIFFLUENCE ALOFT OVER THE TROPICAL WHICH IS ENHANCING SOME OF THE ACTIVITY IN ITS VICINITY. WATER VAPOR IMAGERY INDICATES DRY AIR IS WRAPPING AROUND THE SRN EXTENT OF THE UPPER RIDGE WHICH IS FURTHER SUPPORTING THE FAIR WEATHER. WITH MOISTURE ALREADY IN PLACE ACROSS THE NE GULF...DAYTIME HEATING 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 HAS NOW MOVED OVER 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. STRONG SHOWERS/THUNDERSTORMS ARE CURRENTLY FROM 8N-12N BETWEEN 74W-80W...AND FROM 11N-13N BETWEEN 80W-83W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO ACROSS HISPANIOLA FROM 17N-21N BETWEEN 67W-70W...WITH ISOLATED ACTIVITY N OF 16N BETWEEN 65W-77W. THIS ACTIVITY IS GENERATED BY THE COMBINATION OF ENHANCED MOISTURE ACROSS THIS AREA EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY ALONG WITH DIFFLUENCE ALOFT AROUND A HORIZONTALLY ALIGNED UPPER LEVEL TROUGH ALONG 20N CENTERED OVER CUBA NEAR 21N79W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE ALSO ACROSS THE WINDWARD ISLANDS E OF 66W DUE TO TROPICAL WAVE MOVING INTO THE ERN CARIBBEAN. 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 PROGRESS OF THIS SCENARIO. ATLANTIC OCEAN... SURFACE RIDGING DOMINATES THE MAJORITY OF THE ATLC ANCHORED BY A 1030 MB AZORES HIGH NEAR 40N27W 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 CENTRAL CUBA. THIS IS PRODUCING SOME UPPER LEVEL CLOUDS AND ISOLATED SHOWERS FROM 23N-32N BETWEEN 50W-60W. UPPER LEVEL RIDGING COVERS MUCH OF THE ERN ATLC CENTERED NEAR 36N34W. 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 25N40W...AND AN UPPER LEVEL RIDGE IS CENTERED OFF THE W COAST OF AFRICA NEAR 19 FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 131116 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1100 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE ERN TRPCL ATLC IS ALONG 15N28W 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 ACROSS THE LESSER ANTILLES EXTENDS FROM NEAR 19N59W TO 10N63W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 13N-18N BETWEEN 58W-62W...AND FROM 13N-15N BETWEEN 62W-66W. TROPICAL WAVE PREVIOUSLY E OF THE YUCATAN PENINSULA HAS BEEN RELOCATED FARTHER W AND NOW EXTENDS ALONG 22N92W TO 15N92W MOVING W 15-20 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE SW GULF OF MEXICO. THE WAVE CONTINUES TO LIE UNDER DIFFLUENT FLOW ALOFT WHICH IS HELPING ENHANCE CONVECTION. SCATTERED MODERATE/STRONG CONVECTION IS FROM 15N-22N BETWEEN 93W-95W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 21N ALONG 17N14W 11N22W 8N35W. ITCZ CONTINUES FROM 8N35W TO 5N56W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-7N BETWEEN 12W-15W...AND FROM 7N-9N BETWEEN 27W-32W. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE IN THE BAY OF CAMPECHE IS CAUSING SCATTERED SHOWERS/THUNDERSTORMS S OF 24N BETWEEN 92W-98W. 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 AXIS. A FEW ISOLATED SHOWERS THUNDERSTORMS ARE NOTED ACROSS THE NRN GULF N OF 26N BETWEEN 83W-93W WHERE ENHANCED MOISTURE VALUES ARE INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. ALOFT...AN UPPER LEVEL RIDGE COVERS THE NRN GULF CENTERED OVER CENTRAL ALABAMA. AN INVERTED UPPER LEVEL TROUGH COVERS THE FAR SW GULF WITH AXIS OVER MEXICO. A WEAK AND NARROW UPPER RIDGE IS TO THE E EXTENDING ACROSS THE YUCATAN PENINSULA. THIS PATTERN IS CREATING DIFFLUENCE ALOFT OVER THE TROPICAL WHICH IS ENHANCING SOME OF THE ACTIVITY IN ITS VICINITY. WATER VAPOR IMAGERY INDICATES DRY AIR IS WRAPPING AROUND THE SRN EXTENT OF THE UPPER RIDGE WHICH IS FURTHER SUPPORTING THE FAIR WEATHER. WITH MOISTURE ALREADY IN PLACE ACROSS THE NE GULF...DAYTIME HEATING 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 HAS NOW MOVED OVER 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. STRONG SHOWERS/THUNDERSTORMS ARE CURRENTLY FROM 8N-12N BETWEEN 74W-80W...AND FROM 11N-13N BETWEEN 80W-83W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALSO ACROSS HISPANIOLA FROM 17N-21N BETWEEN 67W-70W...WITH ISOLATED ACTIVITY N OF 16N BETWEEN 65W-77W. THIS ACTIVITY IS GENERATED BY THE COMBINATION OF ENHANCED MOISTURE ACROSS THIS AREA EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY ALONG WITH DIFFLUENCE ALOFT AROUND A HORIZONTALLY ALIGNED UPPER LEVEL TROUGH ALONG 20N CENTERED OVER CUBA NEAR 21N79W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE ALSO ACROSS THE WINDWARD ISLANDS E OF 66W DUE TO TROPICAL WAVE MOVING INTO THE ERN CARIBBEAN. 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 PROGRESS OF THIS SCENARIO. ATLANTIC OCEAN... SURFACE RIDGING DOMINATES THE MAJORITY OF THE ATLC ANCHORED BY A 1030 MB AZORES HIGH NEAR 40N27W 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 CENTRAL CUBA. THIS IS PRODUCING SOME UPPER LEVEL CLOUDS AND ISOLATED SHOWERS FROM 23N-32N BETWEEN 50W-60W. UPPER LEVEL RIDGING COVERS MUCH OF THE ERN ATLC CENTERED NEAR 36N34W. 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 25N40W...AND AN UPPER LEVEL RIDGE IS CENTERED OFF THE W COAST OF AFRICA NEAR 19 FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON