000 AXNT20 KNHC 082353 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL STORM PHILIPPE IS CENTERED NEAR 35.3N 46.0W AT 08/2100 UTC OR ABOUT 940 NM W OF THE AZORES MOVING NE AT 26 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE CONVECTION IS FROM 36N-38N BETWEEN 43W-47W...AND WITHIN 60 NM EITHER SIDE OF A LINE FROM 32N43W TO 27N48W. SEE LATEST NHC FORECAST/ADVISORY UNDER THE AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. AN AREA OF BROAD SURFACE TROUGHING INDUCED BY AN UPPER LEVEL LOW CENTERED OVER ALABAMA AND AN UPPER LEVEL TROUGH AXIS EXTENDING ACROSS THE EASTERN GULF ALONG 85W IS SUPPORTING A LARGE AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS FROM 17N-31N BETWEEN 66W-83W...INCLUDING THE GREATER ANTILLES...THE BAHAMAS...AND THE FLORIDA PENINSULA. WHILE MOST OF THIS AREA LIES BENEATH UPPER LEVEL DIFFLUENT FLOW EAST OF THE TROUGH AXIS AND SURFACE PRESSURES CONTINUE TO GRADUALLY FALL...THE WEAK LOWER PRESSURE AREA IS FORECAST TO GRADUALLY DEVELOP OVER THE NEXT COUPLE OF DAYS. REGARDLESS OF DEVELOPMENT...HEAVY RAINFALL AND STRONG WINDS OF GALE FORCE ARE NOTED N OF 26N W OF 65W IN THE SW NORTH ATLC WATERS. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 07N51W TO 15N499W MOVING W 15-20 KT. TOTAL PRECIPITABLE WATER IMAGERY SHOWS A POLEWARD EXTENSION OF LOW-LEVEL MOISTURE IN THE VICINITY OF THE WAVE BETWEEN 45W-53W. SCATTERED MODERATE CONVECTION IS FROM 07N-12N BETWEEN 48W-54W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N17W TO 14N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N24W TO 04N37W TO 08N48W. ISOLATED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 20W-30W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 02N-09N BETWEEN 32W-41W...AND FROM 06N-12N BETWEEN 41W-48W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW IS CENTERED OVER ALABAMA NEAR 33N87W WHICH EXTENDS A TROUGH AXIS SOUTHWARD ALONG 85W OVER THE EASTERN GULF AND INTO THE NW CARIBBEAN SEA. EAST OF THIS UPPER LEVEL TROUGH AXIS...CONSIDERABLE MIDDLE TO UPPER LEVEL DIFFLUENCE IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS MUCH OF THE FLORIDA PENINSULA AND PORTIONS OF THE EASTERN GULF E OF 85W. FARTHER WEST OVER THE REMAINDER OF THE BASIN...A WEAK SURFACE RIDGE AXIS EXTENDS FROM THE SE CONUS NEAR 30N89W TO EAST-CENTRAL MEXICO NEAR 20N97W. SOUTHEASTERLY RETURN FLOW IS NOTED ACROSS PORTIONS OF THE NW GULF THIS EVENING WITH ISOLATED SHOWERS AND TSTMS OCCURRING N OF 27N W OF 92W. OVER THE NEXT FEW DAYS AS SURFACE RIDGING REMAINS STRONG ACROSS THE EASTERN CONUS AND THE DEVELOPING AREA OF SURFACE TROUGHING ACROSS FLORIDA REMAINS NEARLY STATIONARY...A STRONG PRESSURE GRADIENT IS FORECAST TO MAINTAIN 20-25 KT EASTERLY WINDS ACROSS MUCH OF THE NE GULF...WITH GALE FORCE CONDITIONS EXPECTED N OF 27N E OF 89W THIS EVENING THROUGH LATE SUNDAY. CARIBBEAN SEA... THE UPPER LEVEL TROUGH OVER THE EASTERN GULF OF MEXICO EXTENDS TO A BASE OVER THE NW CARIBBEAN. THIS UPPER LEVEL TROUGH IS SUPPORTING A WEAK SURFACE TROUGH EXTENDING FROM CENTRAL CUBA NEAR 22N80W TO 17N86W. WITH UPPER LEVEL DIFFLUENCE MAXIMIZED EAST OF THE UPPER LEVEL TROUGH AXIS...SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER THE CARIBBEAN WATERS BETWEEN 67W-84W. FARTHER SOUTH...LOW-LEVEL CYCLONIC WINDS WRAP INTO THE MONSOON TROUGH AXIS ANALYZED ALONG 11N WITH SCATTERED SHOWERS AND TSTMS S OF 13N BETWEEN 72W-85W...INCLUDING NORTHERN COLOMBIA...AND MUCH OF PANAMA AND COSTA RICA. ACROSS THE FAR EASTERN CARIBBEAN...AN UPPER LEVEL RIDGE AXIS EXTENDS ALONG 64W...WITH WATER VAPOR IMAGERY INDICATING DRY AIR E OF THE AXIS WHICH IS MAINTAINING MOSTLY CLEAR SKIES AND FAIR WEATHER CONDITIONS THIS EVENING. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH OVER THE EASTERN GULF OF MEXICO IS PROVIDING FOR A LARGE AREA OF DIFFLUENT FLOW ALOFT ACROSS THE SW NORTH ATLC THIS EVENING. THIS IS HELPING SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS W OF 65W. FARTHER EAST...A SURFACE TROUGH EXTENDS FROM SE OF TROPICAL STORM PHILIPPE NEAR 32N45W ALONG 27N50W TO 24N57W TO 24N66W WHERE THE BOUNDARY TRANSITIONS TO A SHEAR LINE WESTWARD TO 25N73W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 60 NM EITHER SIDE OF A LINE FROM 32N43W TO 27N48W. ELSEWHERE WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH ISOLATED SHOWERS REMAIN POSSIBLE. THIS WEAK SURFACE TROUGH IS SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH TO THE N OF THE DISCUSSION AREA N OF 30N BETWEEN 45W-60W. IT IS ALSO CURRENTLY IMPARTING UPPER LEVEL SHEAR UPON PHILIPPE. THE REMAINDER OF THE EASTERN ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED NW OF THE IBERIAN PENINSULA NEAR 46N13W. THE SURFACE RIDGE AXIS EXTENDS FROM THE HIGH ACROSS THE AZORES TO 32N30W TO 23N45W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN