000 AXNT20 KNHC 252354 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUN 25 2012 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... TROPICAL STORM DEBBY IS CENTERED NEAR 29.1N 85.2W AT 26/0000 UTC OR ABOUT 26 NM SSW OF APALACHICOLA FLORIDA NEAR STATIONARY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE/STRONG CONVECTION HAS REDEVELOPED N OF THE CENTER OVER THE PAST FEW HOURS COVERING THE AREA N OF 29N TO INLAND OVER THE FLORIDA PANHANDLE E OF 86W TO OVER THE FLORIDA PENINSULA. OUTER RAINBANDS CONSISTING OF SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE N OF 25N BETWEEN 79W-88W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 13N29W ALONG 7N31W TO 3N30W MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. WAVE REMAINS TO THE S OF THE SAHARAN DUST THAT COVERS THE TROPICAL ATLC. THUS...NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE EXTENDS FROM 17N59W TO 10N60W MOVING W NEAR 20 KT. WAVE IS LEADING A WEAK SURGE OF MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. WAVE AS ALSO AT THE LEADING EDGE OF THE SAHARAN DUST THAT COVERS THE TROPICAL ATLC. SCATTERED SHOWERS ARE MOVING TOWARD THE LESSER ANTILLES WITH SHOWERS OBSERVED OVER BARBADOS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 15N17W CONTINUING TO 7N29W. THE ITCZ AXIS STARTS W OF THE TROPICAL WAVE NEAR 5N36W CONTINUING TO INLAND OVER SOUTH AMERICA NEAR 4N52W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE INLAND AND WITHIN 90 NM ALONG THE COAST OF W AFRICA BETWEEN THE LIBERIA/SIERRA LEONE BORDER AND DAKAR SENEGAL. ...DISCUSSION... GULF OF MEXICO... TROPICAL STORM DEBBY REMAINS A CONCERN FOR THE NE GULF AND MOST OF FLORIDA THIS EVENING. SEE SPECIAL FEATURES ABOVE. AN UPPER LOW IS OVER THE W GULF CENTERED NEAR 25N95W WHILE AN UPPER RIDGE DOMINATES THE REMAINDER OF THE GULF ANCHORED OVER THE YUCATAN CHANNEL AND EXTENDING INTO THE W ATLC AND CARIBBEAN. A SURFACE TROUGH IS ACROSS THE S GULF AT 25/2100 UTC EXTENDING FROM 26N83W ALONG 23N87W TO 21N93W. THE UPPER FLOW COUPLED WITH THE SURFACE TROUGH IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 120/150 NM S OF THE TROUGH BETWEEN 85W-90W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE S OF 25N E OF 86W TO OVER FLORIDA AND THROUGH THE STRAITS OF FLORIDA. TROPICAL STORM DEBBY IS EXPECTED TO DRIFT VERY SLOWLY NE THROUGH EARLY WED THEN E ACROSS NE FLORIDA THROUGH FRI. CARIBBEAN SEA... THE UPPER RIDGE OVER THE GULF OF MEXICO IS ANCHORED OVER THE YUCATAN CHANNEL AND COVERS THE CARIBBEAN W OF 68W GIVING THAT AREA NE FLOW ALOFT. SCATTERED SHOWERS/THUNDERSTORMS ARE NW OF A LINE FROM CUBA NEAR 22N83W TO THE YUCATAN NEAR 19N87W THROUGH THE YUCATAN CHANNEL INTO THE GULF OF MEXICO. A NARROW UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC THROUGH THE LEEWARD ISLANDS TO THE ABC ISLANDS. ALTHOUGH THE MONSOON TROF EXTENDS ACROSS THE SW CARIBBEAN WITH THE SHOWERS/THUNDERSTORMS REMAINING INLAND OVER COLOMBIA TO COSTA RICA. THIS IS LEAVING THE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS EVENING WITH SOME THIN HIGH CLOUDS STREAMING NE/SW. MODERATE TO FRESH E TO SE TRADE WINDS WILL PREVAIL ACROSS MUCH OF THE CARIBBEAN WITH OCCASIONALLY HIGHER WINDS ALONG THE N COAST OF SOUTH AMERICA. TROPICAL WAVE WILL MOVE ACROSS THE CARIBBEAN TONIGHT THROUGH THU. ATLANTIC OCEAN... OUTER RAINBANDS FROM TROPICAL STORM DEBBY ARE OVER THE FAR W ATLC. SEE SPECIAL FEATURES ABOVE. THE UPPER RIDGE OVER THE GULF OF MEXICO AND CARIBBEAN EXTENDS OVER THE W ATLC WITH THE AXIS THROUGH THE STRAITS OF FLORIDA TO BEYOND 32N62W. DIFFLUENCE ALOFT N OF THE UPPER RIDGE AXIS IS GENERATING SCATTERED SHOWERS AND EMBEDDED CLUSTERS OF THUNDERSTORMS N OF LINE FROM 28N62W TO 25N80W. A NARROW UPPER TROUGH IS TO THE E EXTENDING THROUGH 32N56W ALONG 22N60W INTO THE E CARIBBEAN OVER THE LEEWARD ISLANDS. AN AREA OF SCATTERED SHOWERS/THUNDERSTORMS IS WITHIN 120 NM N OF THE GREATER ANTILLES BEING GENERATED BY THE NE UPPER FLOW AND THE SE SURFACE FLOW. AN UPPER LOW/TROUGH WELL N OF THE REGION IS DRAPING A COLD FRONT INTO THE E/CENTRAL ATLC THROUGH 32N35W TO 28N42W AND A SURFACE TROUGH FROM 32N32W ALONG 28N37W TO 25N44W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 45 NM EITHER SIDE OF THE SURFACE TROUGH. A LARGE SURFACE RIDGE DOMINATES THE ATLC E OF 65W WITH A WEAKNESS IN THE VICINITY OF THE ABOVE FRONT/TROUGH. A 1021 MB HIGH IS IN THE CENTRAL ATLC NEAR 33N51W AND A 1019 MB HIGH IS IN THE E ATLC NEAR 23N30W. VISIBLE SATELLITE IMAGERY SHOWS A BROAD AREA OF SAHARAN DUST COVERING THE TROPICAL ATLC MOSTLY S OF 20N E OF 60W. SURFACE RIDGE WILL PREVAIL THROUGH TUE AS TROPICAL STORM DEBBY DRIFTS SLOWLY NE ACROSS THE NE GULF. A WEAK COLD FRONT WILL MOVE OFF MID ATLC COAST TUE THROUGH WED AND ACT TO PUSH RIDGE S TO ALONG 24N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN