000 AXNT20 KNHC 291153 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUN 29 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 1115 UTC. ...SPECIAL FEATURE... T.S. ARLENE IS CENTERED NEAR 21.8N 95.2W...OR ABOUT 150 M E OF TAMPICO...AS OF 1200 UTC. THE STORM IS MOVING WNW AT 7 KT. MINIMUM CENTRAL PRESSURE IS 1002 MB WHILE MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. ARLENE IS EXPECTED TO SLOWLY DRIFT W TOWARDS THE MEXICAN COAST. SOME STRENGTHENING IS POSSIBLE BEFORE MAKING LANDFALL. SEE NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS WRAPPING AROUND THE ERN SIDE OF THE CENTER ACROSS SRN MEXICO AND THE YUCATAN PENINSULA FROM 16N-23N BETWEEN 90W-94W. STRONG CONVECTION IS ALSO NEAR THE CENTER FROM 20N-23N BETWEEN 94W-96W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS SW OF THE CENTER FROM 17N-22N BETWEEN 95W-98W. ...TROPICAL WAVES... A TROPICAL WAVE IS ACROSS THE CENTRAL ATLC ALONG 13N47W TO 7N48W MOVING W NEAR 15-20 KT. SATELLITE IMAGERY CONTINUES TO SHOW CLEAR CUT LOW LEVEL CYCLONIC FLOW ABOUT THE WAVE AXIS. THE WAVE IS ALSO EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS W OF THE WAVE AXIS FROM 9N-11N BETWEEN 46W-50W...AND FROM 5N-6N BETWEEN 48W-50W. A TROPICAL WAVE IS S OF THE DOMINICAN REPUBLIC ALONG 72W FROM 13N-19N MOVING W NEAR 10 KT. THIS WAVE HAS LOST A LOT OF ITS ENERGY OVER THE PAST 24 HOURS...MOST LIKELY DUE TO THE INTERACTION WITH AN UPPER LEVEL LOW NOW S OF HAITI NEAR 16N73W. MODERATELY HIGHER MOISTURE VALUES STILL REMAIN IN THE VICINITY OF THE WAVE. A CLUSTER OF MODERATE/STRONG CONVECTION IS NEAR THE WAVE AXIS FROM 14N-16N BETWEEN 68W-74W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 23N ALONG 18N8W 15N15W 9N19W 7N24W. THE ITCZ CONTINUES FROM 7N24W ALONG 6N34W 6N46W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 6N-10N BETWEEN 15W-25W...FROM 4N-7N BETWEEN 32W-44W...AND FROM 8N-10N BETWEEN 31W-42W. ...DISCUSSION... GULF OF MEXICO... TROPICAL STORM ARLENE...LOCATED IN THE BAY OF CAMPECHE...IS CURRENTLY AFFECTING MUCH OF THE SW GULF OF MEXICO. SEE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. A SHORTWAVE UPPER TROUGH STILL SITS OVER THE NRN GULF FROM THE FLORIDA PANHANDLE TO NRN MEXICO NEAR 26N99W...WITH AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA TO SRN FLORIDA. THIS PATTERN IS KEEPING MOIST SWLY FLOW OVER MUCH OF THE CENTRAL AND ERN GULF OF MEXICO...WHILE DRY AIR AND SUBSIDENCE COVERS THE FAR NW CORNER MAINTAINING FAIR CONDITIONS. BESIDES THE CONVECTION ASSOCIATED WITH ARLENE...SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE SE GULF FROM 23N-27N BETWEEN 80W-88W. AS OF 0900 UTC...A SURFACE TROUGH IS ANALYZED IN THE NE GULF FROM 31N83W TO 30N88W WITH A LINE OF SHOWERS/THUNDERSTORMS ALONG IT. EXPECT CONTINUED MOISTURE AND SHOWER ACTIVITY TO REMAIN ACROSS MUCH OF THE BASIN OVER THE NEXT 24 HOURS. CARIBBEAN SEA... MUCH OF THE WRN CARIBBEAN IS UNDER FAIR CONDITIONS AS DRY AIR ALOFT IS BEING DOWN SWD BETWEEN AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA TO SRN FLORIDA...AND AN UPPER LEVEL LOW CENTERED S OF HAITI NEAR 16N73W. SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE SW CARIBBEAN ACROSS PANAMA AND COSTA RICA S OF 10N DUE TO THE MONSOON TROUGH EXTENDING FROM COSTA RICA TO NRN COLOMBIA. SIMILAR ACTIVITY IS ALSO E OF BELIZE FROM 16N-19N BETWEEN 87W-88W DUE TO MOISTURE FROM THE SRN GULF. A TROPICAL WAVE IS S OF THE DOMINICAN REPUBLIC SUPPORTING AN AREA OF SHOWERS/THUNDERSTORMS FROM 14N-16N BETWEEN 68W-74W. AN AREA OF ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS IS ALSO MOVING ACROSS THE FAR SE CARIBBEAN FROM 10N-12N E OF 67W. EXPECT POSSIBLE SHOWERS/THUNDERSTORMS TO CONTINUE OVER THE CENTRAL CARIBBEAN AS THE TROPICAL WAVE MOVES WWD. ATLANTIC OCEAN... UPPER LEVEL RIDGING COVERS THE SW ATLC EXTENDING FROM THE YUCATAN PENINSULA AND ACROSS FLORIDA TO NEAR 29N75W. HIGH MOISTURE VALUES FROM THE SW GULF ARE BEING DRAWN INTO THE ATLC IN MOIST SWLY FLOW ALOFT AROUND THE UPPER RIDGE SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ALONG A 150 NM SWATH FROM NEAR 26N80W TO 33N73W. A SURFACE TROUGH...A SPLIT OFF PORTION OF A TROPICAL WAVE IN THE CENTRAL CARIBBEAN...IS N OF TURKS AND CAICOS FROM 24N69W TO 22N71W SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS FROM 22N-25N BETWEEN 68W-72W. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1024 MB HIGH NEAR 31N49W MAINTAINING FAIR WEATHER ACROSS THE CENTRAL AND ERN ATLC. ALOFT...AN UPPER LEVEL LOW IS CENTERED NEAR 28N51W. AN AREA OF ISOLATED SHOWERS/THUNDERSTORMS IS NW OF THIS UPPER LOW N OF 29N BETWEEN 56W-62W. AN UPPER LEVEL RIDGE IS ALONG 40W...WHILE AN UPPER TROUGH COVER THE ERN ATLC WITH AXIS BETWEEN THE AZORES AND CANARY ISLANDS. UPPER RIDGING COVERS THE TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 291153 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUN 29 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 1115 UTC. ...SPECIAL FEATURE... T.S. ARLENE IS CENTERED NEAR 21.8N 95.2W...OR ABOUT 150 M E OF TAMPICO...AS OF 1200 UTC. THE STORM IS MOVING WNW AT 7 KT. MINIMUM CENTRAL PRESSURE IS 1002 MB WHILE MAXIMUM SUSTAINED WINDS ARE 35 KT WITH GUSTS TO 45 KT. ARLENE IS EXPECTED TO SLOWLY DRIFT W TOWARDS THE MEXICAN COAST. SOME STRENGTHENING IS POSSIBLE BEFORE MAKING LANDFALL. SEE NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS WRAPPING AROUND THE ERN SIDE OF THE CENTER ACROSS SRN MEXICO AND THE YUCATAN PENINSULA FROM 16N-23N BETWEEN 90W-94W. STRONG CONVECTION IS ALSO NEAR THE CENTER FROM 20N-23N BETWEEN 94W-96W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS SW OF THE CENTER FROM 17N-22N BETWEEN 95W-98W. ...TROPICAL WAVES... A TROPICAL WAVE IS ACROSS THE CENTRAL ATLC ALONG 13N47W TO 7N48W MOVING W NEAR 15-20 KT. SATELLITE IMAGERY CONTINUES TO SHOW CLEAR CUT LOW LEVEL CYCLONIC FLOW ABOUT THE WAVE AXIS. THE WAVE IS ALSO EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS W OF THE WAVE AXIS FROM 9N-11N BETWEEN 46W-50W...AND FROM 5N-6N BETWEEN 48W-50W. A TROPICAL WAVE IS S OF THE DOMINICAN REPUBLIC ALONG 72W FROM 13N-19N MOVING W NEAR 10 KT. THIS WAVE HAS LOST A LOT OF ITS ENERGY OVER THE PAST 24 HOURS...MOST LIKELY DUE TO THE INTERACTION WITH AN UPPER LEVEL LOW NOW S OF HAITI NEAR 16N73W. MODERATELY HIGHER MOISTURE VALUES STILL REMAIN IN THE VICINITY OF THE WAVE. A CLUSTER OF MODERATE/STRONG CONVECTION IS NEAR THE WAVE AXIS FROM 14N-16N BETWEEN 68W-74W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 23N ALONG 18N8W 15N15W 9N19W 7N24W. THE ITCZ CONTINUES FROM 7N24W ALONG 6N34W 6N46W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 6N-10N BETWEEN 15W-25W...FROM 4N-7N BETWEEN 32W-44W...AND FROM 8N-10N BETWEEN 31W-42W. ...DISCUSSION... GULF OF MEXICO... TROPICAL STORM ARLENE...LOCATED IN THE BAY OF CAMPECHE...IS CURRENTLY AFFECTING MUCH OF THE SW GULF OF MEXICO. SEE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. A SHORTWAVE UPPER TROUGH STILL SITS OVER THE NRN GULF FROM THE FLORIDA PANHANDLE TO NRN MEXICO NEAR 26N99W...WITH AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA TO SRN FLORIDA. THIS PATTERN IS KEEPING MOIST SWLY FLOW OVER MUCH OF THE CENTRAL AND ERN GULF OF MEXICO...WHILE DRY AIR AND SUBSIDENCE COVERS THE FAR NW CORNER MAINTAINING FAIR CONDITIONS. BESIDES THE CONVECTION ASSOCIATED WITH ARLENE...SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE SE GULF FROM 23N-27N BETWEEN 80W-88W. AS OF 0900 UTC...A SURFACE TROUGH IS ANALYZED IN THE NE GULF FROM 31N83W TO 30N88W WITH A LINE OF SHOWERS/THUNDERSTORMS ALONG IT. EXPECT CONTINUED MOISTURE AND SHOWER ACTIVITY TO REMAIN ACROSS MUCH OF THE BASIN OVER THE NEXT 24 HOURS. CARIBBEAN SEA... MUCH OF THE WRN CARIBBEAN IS UNDER FAIR CONDITIONS AS DRY AIR ALOFT IS BEING DOWN SWD BETWEEN AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA TO SRN FLORIDA...AND AN UPPER LEVEL LOW CENTERED S OF HAITI NEAR 16N73W. SCATTERED SHOWERS/THUNDERSTORMS ARE IN THE SW CARIBBEAN ACROSS PANAMA AND COSTA RICA S OF 10N DUE TO THE MONSOON TROUGH EXTENDING FROM COSTA RICA TO NRN COLOMBIA. SIMILAR ACTIVITY IS ALSO E OF BELIZE FROM 16N-19N BETWEEN 87W-88W DUE TO MOISTURE FROM THE SRN GULF. A TROPICAL WAVE IS S OF THE DOMINICAN REPUBLIC SUPPORTING AN AREA OF SHOWERS/THUNDERSTORMS FROM 14N-16N BETWEEN 68W-74W. AN AREA OF ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS IS ALSO MOVING ACROSS THE FAR SE CARIBBEAN FROM 10N-12N E OF 67W. EXPECT POSSIBLE SHOWERS/THUNDERSTORMS TO CONTINUE OVER THE CENTRAL CARIBBEAN AS THE TROPICAL WAVE MOVES WWD. ATLANTIC OCEAN... UPPER LEVEL RIDGING COVERS THE SW ATLC EXTENDING FROM THE YUCATAN PENINSULA AND ACROSS FLORIDA TO NEAR 29N75W. HIGH MOISTURE VALUES FROM THE SW GULF ARE BEING DRAWN INTO THE ATLC IN MOIST SWLY FLOW ALOFT AROUND THE UPPER RIDGE SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ALONG A 150 NM SWATH FROM NEAR 26N80W TO 33N73W. A SURFACE TROUGH...A SPLIT OFF PORTION OF A TROPICAL WAVE IN THE CENTRAL CARIBBEAN...IS N OF TURKS AND CAICOS FROM 24N69W TO 22N71W SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS FROM 22N-25N BETWEEN 68W-72W. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1024 MB HIGH NEAR 31N49W MAINTAINING FAIR WEATHER ACROSS THE CENTRAL AND ERN ATLC. ALOFT...AN UPPER LEVEL LOW IS CENTERED NEAR 28N51W. AN AREA OF ISOLATED SHOWERS/THUNDERSTORMS IS NW OF THIS UPPER LOW N OF 29N BETWEEN 56W-62W. AN UPPER LEVEL RIDGE IS ALONG 40W...WHILE AN UPPER TROUGH COVER THE ERN ATLC WITH AXIS BETWEEN THE AZORES AND CANARY ISLANDS. UPPER RIDGING COVERS THE TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON