000 AXNT20 KNHC 300553 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI SEP 30 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 0445 UTC. ...SPECIAL FEATURES... HURRICANE OPHELIA IS CENTERED NEAR 22.0N 62.5W AT 30/0600 UTC OR ABOUT 635 NM S OF BERMUDA MOVING N-NW AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 976 MB. MAXIMUM SUSTAINED WIND SPEED IS 80 KT WITH GUSTS TO 100 KT. PLEASE SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. OPHELIA HAS STRENGTHEN WITH AN APPARENT EYE FEATURE. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 90 NM OF THE CENTER IN ALL QUADRANTS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE AREA FROM 20N-26N BETWEEN 57W-63W AND WITHIN 45 NM OF LINE FROM 18N59W ACROSS THE LEEWARD ISLANDS NEAR GUADELOUPE INTO THE E CARIBBEAN TO NEAR 15N65W. TROPICAL STORM PHILIPPE IS CENTERED NEAR 21.2N 44.0W AT 30/0300 UTC OR ABOUT 1040 NM E-NE OF THE LEEWARD ISLANDS AND ABOUT 1180 NM W-NW OF THE CAPE VERDE ISLANDS MOVING NW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. PHILIPPE HAS A UNORGANIZED APPEARANCE ON SATELLITE IMAGERY WITH SCATTERED MODERATE/STRONG CONVECTION WITHIN 60/75 NM 23N BETWEEN 41W-44W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE REMAINDER OF THE AREA WITHIN 120 NM OF LINE FROM 23N37W 22N44W TO 20N46W. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED 10N33W 5N35W TO 2N336W MOVING W NEAR 15 KT. WAVE CONTINUES TO BE DIFFICULT TO DISCERN ON SATELLITE IMAGERY. THE UPPER LEVEL SATELLITE WINDS SHOW NO DISTINCT CURVATURE AND THE LOCATION IS BASED ON PERSISTENCE. NO ASSOCIATED SHOWERS/CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA ENTERING THE E TROPICAL ATLC NEAR 18N16W TO 17N21W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 45 NM ALONG THE COAST OF W AFRICA BETWEEN 8N-10N. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 3N-7N BETWEEN 26W-32W AND FROM 10N-13N BETWEEN 43W-47W. ...DISCUSSION... GULF OF MEXICO... THE LARGE UPPER LOW REMAINS CENTERED OVER THE GREAT LAKES AREA COVERING THE CONUS FROM THE CENTRAL PLAIN STATES INTO THE NW ATLC EXTENDING A BROAD UPPER TROUGH INTO THE N GULF N OF 28N SUPPORTING YET ANOTHER FRONTAL BOUNDARY THAT REMAINS INLAND OVER THE CONUS. A SHORTWAVE UPPER TROUGH IS EMBEDDED WITHIN THIS FLOW EXTENDING FROM CENTRAL GEORGIA TO A SMALL UPPER LOW JUST OFF THE COAST OF PANAMA CITY FLORIDA. A SECOND UPPER SHORTWAVE AND SMALL UPPER LOW IS OVER THE RIO GRANDE NEAR LAREDO TEXAS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER E TEXAS INTO THE FAR W GULF WATERS WITHIN 45 NM ALONG THE COAST OF TEXAS. A SURFACE TROUGH EXTENDS AT 30/0300 UTC FROM SE GEORGIA OVER ORLANDO FLORIDA INTO THE GULF NEAR FORT MYERS TO 25N83W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 30 NM OF THE THIS TROUGH MAINLY S OF 27N. A BROAD UPPER RIDGE COVERS THE REMAINDER OF THE GULF ANCHORED OVER THE E PACIFIC REGION GIVING MOST OF THE GULF WATERS NEAR WESTERLY FLOW ALOFT WITH A WEAK 1016 MB HIGH LOCATED OVER S TEXAS. WEAK HIGH PRESSURE WILL DISSIPATE FRI MORNING. A COLD FRONT WILL MOVE INTO THE N GULF FRI AFTERNOON REACHING FROM SW FLORIDA TO NE MEXICO SAT MORNING THEN STALL FROM THE STRAITS OF FLORIDA TO THE YUCATAN SUN MORNING. STRONG HIGH PRESSURE WILL BUILD SE BEHIND THE FRONT ACROSS THE N CENTRAL GULF SUN THROUGH TUE. CARIBBEAN SEA... THE PRIMARY CONCERN AGAIN TONIGHT IS HURRICANE OPHELIA N OF THE LEEWARD/VIRGIN ISLANDS...SEE SPECIAL FEATURE SECTION ABOVE. THE UPPER RIDGE OVER THE S GULF OF MEXICO EXTENDS OVER MOST OF THE CARIBBEAN WITH THE EXCEPTION OF THE NE CARIBBEAN WHICH IS UNDER THE INFLUENCE OF THE UPPER RIDGE ASSOCIATED WITH HURRICANE OPHELIA. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N76W INTO THE E PACIFIC REGION OVER COSTA RICA NEAR 10N84W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N TO INLAND OVER COLOMBIA AND PANAMA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM 14N78W TO OVER HAITI NEAR 20N72W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES AGAIN TONIGHT. A WEAK PRESSURE PATTERN WILL CONTINUE OVER THE CARIBBEAN THROUGH SUN. ATLANTIC OCEAN... THE PRIMARY CONCERN TONIGHT IS HURRICANE OPHELIA N OF THE LEEWARD/VIRGIN ISLANDS AND TROPICAL STORM PHILIPPE OVER THE CENTRAL ATLC...SEE SPECIAL FEATURE SECTION ABOVE. THE BROAD UPPER TROUGH OVER THE US CONUS EXTENDS OVER THE W ATLC N OF 28N TO 70W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF LINE FROM 28N71W TO BEYOND 32N70W AND WITHIN 30 NM OF LINE FROM 30N79W TO 33N76W. AN UPPER RIDGE COVERS THE REMAINDER OF THE W ATLC E OF HURRICANE OPHELIA WITH THE AXIS EXTENDING FROM THE N COAST OF CUBA NEAR 22N76W TO 28N71W PROVIDING DIFFLUENT ENVIRONMENT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE BAHAMA ISLANDS INCLUDING THE TURKS AND CAICOS. AN UPPER TROUGH EXTENDS S INTO THE CENTRAL ATLC N OF 26N BETWEEN 30W-45W SUPPORTING A COLD FRONT THAT EXTENDS INTO THE REGION NEAR 32N31W TO 29N42W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120 NM SE OF THE FRONT E OF 35W. A WEAK SURFACE RIDGE COVERS THE E ATLC ANCHORED BY A 1020 MB HIGH NEAR 27N29W. A WEAK FRONT WILL MOVE OFF THE NE FLORIDA COAST FRI MORNING WHERE IT WILL STALL. A REINFORCING COLD FRONT WILL MOVE OFF THE COAST FRI NIGHT AND MERGE WITH THE STALLED FRONT REACHING FROM BERMUDA TO E CUBA SAT NIGHT WHERE IT WILL THEN STALL AND DISSIPATE BY MON. HIGH PRESSURE WILL BUILD IN FROM THE NE LATE MON AND TUE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW