000 AXNT20 KNHC 081802 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT OCT 08 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM PHILIPPE IS CENTERED NEAR 33.2N 47.9W AT 08/1500 UTC OR ABOUT 1055 NM W OF THE AZORES ISLANDS MOVING NE AT 25 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 991 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. PHILIPPE IS EXPECTED TO BECOME POST-TROPICAL WITHIN THE NEXT 12-24 HOURS. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER THE AWIPS/WMO HEADERS MIATCMAT2/ WTNT22 KNHC FOR MORE DETAILS. PHILIPPE REMAINS UNDER STRONG SW SHEAR WITH THE LOW LEVEL CENTER EXPOSED. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS FROM 32N-36N BETWEEN 43W-49W...AND FROM 27N-32N BETWEEN 45W-49W. AN AREA OF BROAD SURFACE TROUGHING IS OVER THE SW N ATLC SUPPORTING A LARGE AREA OF SHOWERS/THUNDERSTORMS ACROSS CUBA...THE BAHAMAS...AND FLORIDA. THIS AREA LIES UNDERNEATH DIFFLUENT FLOW ALOFT WHICH IS HELPING SUPPORT THE WIDESPREAD ACTIVITY. GRADUAL DEVELOPMENT OF THIS AREA OF DISTURBED WEATHER IS POSSIBLE OVER THE NEXT COUPLE OF DAYS. REGARDLESS OF DEVELOPMENT...HEAVY RAINFALL AND GUSTY WINDS ARE EXPECTED WITH GALE FORCE WINDS ALREADY NOTED N OF 26N W OF 65W. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 12N47W TO 5N49W MOVING W 15-20 KT. TOTAL PRECIPITABLE WATER IMAGERY INDICATES A SURGE OF MOISTURE JUST E OF THE WAVE AXIS WITH MAXIMUM VALUES ALONG THE ITCZ AXIS. NUMEROUS STRONG CONVECTION IS FROM 6N-9N BETWEEN 47W-50W...WITH SCATTERED MODERATE CONVECTION ELSEWHERE FROM 6N-12N BETWEEN 45W-52W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS JUST OFF THE AFRICAN COAST OF SENEGAL FROM 15N17W TO 14N19W. THE ITCZ AXIS BEGINS NEAR 6N24W CONTINUING ALONG 6N33W 6N40W 7N45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 5N-8N BETWEEN 20W-24W. SIMILAR ACTIVITY IS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 28W-35W...AND WITHIN 200 NM EITHER SIDE OF THE AXIS BETWEEN 35W-45W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW SPINNING OVER THE FLORIDA PANHANDLE AND SW GEORGIA WITH AXIS EXTENDING SWD ALONG 85W IS PLACING SIGNIFICANT MOISTURE AND DIFFLUENT FLOW ALOFT ACROSS THE ERN GULF AND FLORIDA E OF 84W. AT THE SURFACE...BROAD CYCLONIC FLOW IS ACROSS FLORIDA AND THE FAR ERN GULF WITH BROAD RIDGING ACROSS THE REMAINDER OF THE BASIN EXTENDING FROM A PAIR OF 1034 MB HIGHS OVER VIRGINA AND PENNSYLVANIA. A STRONG SURFACE PRESSURE GRADIENT MAINTAINS 20-25 KT ELY WINDS ACROSS MUCH OF THE NRN AND ERN GULF WITH HIGHER GUSTS. SLIGHTLY WEAKER ELY WINDS OF 10-15 KTS ARE ACROSS THE SRN GULF. WHILE MUCH OF THE SHOWER ACTIVITY ASSOCIATED WITH THE UPPER TROUGH REMAINS INLAND OVER THE ERN HALF OF THE FLORIDA PENINSULA...A LINE OF SHOWERS/THUNDERSTORMS HAS FORMED ALONG A LINE FROM 24N82W TO 26N88W. THIS IS DUE TO SPEED CONVERGENCE BETWEEN THE STRONGER WINDS TO THE N AND WEAKER WINDS TO THE S. THE REMAINDER OF THE BASIN IS UNDER MOSTLY CLEAR SKIES DUE TO DRY AIR ALOFT AROUND THE WRN SIDE OF THE UPPER TROUGH. A FEW ISOLATED SHOWERS ARE NOTED OVER THE FAR NW GULF. EXPECT MOIST CONDITIONS TO REMAIN ACROSS THE FLORIDA PENINSULA AS THE UPPER LEVEL TROUGH REMAINS QUASI-STATIONARY. CARIBBEAN SEA... THE UPPER TROUGH OVER THE ERN GULF OF MEXICO EXTENDS OVER THE NW CARIBBEAN SUPPORTING A SURFACE TROUGH EXTENDING FROM S OF CENTRAL CUBA TO N OF HONDURAS NEAR 17N87W. SURFACE CONVERGENCE COMBINED WITH UPPER LEVEL DIFFLUENCE IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS MAINLY E OF THE SURFACE TROUGH FROM 17N-22N BETWEEN 74W-80W. ISOLATED SHOWERS/THUNDERSTORMS ARE FROM 16N-19N BETWEEN 80W-87W. A SHORTWAVE UPPER TROUGH EXTENDS ACROSS HAITI WHICH IS PLACING UPPER LEVEL DIFFLUENCE ACROSS THE DOMINICAN REPUBLIC WHERE STRONG SHOWERS/THUNDERSTORMS ARE OCCURRING FROM 15N-19N BETWEEN 68W-72W. A SMALL CLUSTER OF STORMS IS ALSO OVER NE PUERTO RICO. A FEW SCATTERED SHOWERS ARE OFF THE COASTS OF NICARAGUA AND COSTA RICA MOST LIKELY DUE TO WIND CONVERGENCE AGAINST THE COAST. SOME OF THE ACTIVITY IS ALSO INFLUENCED BY THE MONSOON TROUGH AXIS EXTENDING ACROSS COSTA RICA TO NRN COLOMBIA/VENEZUELA. ACROSS THE ERN CARIBBEAN...AN UPPER LEVEL RIDGE EXTENDS ALONG 64W. E OF THE UPPER RIDGE...DRY AIR IS INFLUENCING THE LESSER ANTILLES MAINTAINING FAIR WEATHER. EXPECT MOIST CONDITIONS TO REMAIN ACROSS THE NW AND CENTRAL CARIBBEAN FOR THE NEXT COUPLE OF DAYS AS THE UPPER TROUGH OVER THE WRN CARIBBEAN REMAINS QUASI-STATIONARY. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH OVER THE ERN GULF OF MEXICO IS PLACING A LARGE AREA OF DIFFLUENT FLOW ALOFT ACROSS THE WRN ATLC. THIS IS HELPING SUPPORT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS W OF 65W. STRONG SHOWERS/THUNDERSTORMS ARE ALSO ACROSS MUCH OF THE ERN COAST OF THE FLORIDA PENINSULA WHERE FLOOD WATCHES ARE CURRENTLY IN EFFECT. GUSTY CONDITIONS ARE ALSO BEING EXPERIENCED ALONG THE ENTIRE COAST DUE TO THE STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE N AND LOWER PRESSURES OVER THE CARIBBEAN. IN FACT...GALE FORCE WINDS ARE N OF 26N W OF 65W. GUSTY AND MOIST CONDITIONS ARE EXPECTED TO REMAIN OVER THE ENTIRE SW N ATLC FOR THE NEXT COUPLE OF DAYS. SEE SPECIAL FEATURES FOR MORE DETAILS ON THIS AREA OF DISTURBED WEATHER. FARTHER E...A SURFACE TROUGH EXTENDS SE OF T.S. PHILIPPE ALONG 27N53W 23N61W 23N69W. SCATTERED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE AXIS MERGING INTO THE LARGER AREA OF ACTIVITY OVER THE WRN ATLC. THIS TROUGH IS SUPPORTED BY AN UPPER LEVEL TROUGH TO THE N ALONG 53W WHICH IS ALSO CURRENTLY SHEARING APART PHILIPPE. DIFFLUENCE BETWEEN THIS UPPER TROUGH AND AN UPPER LEVEL RIDGE EXTENDING FROM THE ERN CARIBBEAN TO NEAR 31N43W IS SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM N OF 26N BETWEEN 43W-50W. THE REMAINDER OF THE BASIN IS DOMINATED BY BROAD SURFACE RIDGING AROUND A 1035 MB HIGH NW OF SPAIN NEAR 45N14W SUPPORTED BY A STRONG UPPER LEVEL HIGH NEAR 39N15W. AN ELONGATED UPPER LEVEL LOW IS SANDWICHED BETWEEN THIS UPPER HIGH AND THE RIDGE EXTENDING FROM THE CARIBBEAN TO NEAR 31N43W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON