000 AXNT20 KNHC 272356 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 27 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 2330 UTC. ...SPECIAL FEATURES... TROPICAL STORM PHILIPPE IS CENTERED NEAR 16.0N 35.7W AT 27/2100 UTC OR ABOUT 690 NM W OF THE CAPE VERDE ISLANDS MOVING WNW AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION CONTINUES TO BE SHEARED TO THE EAST OF PHILIPPE FROM 14N-19N BETWEEN 30W-35W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. THE PREVIOUS REMNANTS OF OPHELIA HAVE REGENERATED INTO A TROPICAL DEPRESSION AS OF 2100 UTC. T.D. OPHELIA IS CURRENTLY CENTERED NEAR 17.6N 60.5W...OR ABOUT 150 NM ESE OF THE NRN LEEWARD ISLANDS...MOVING WNW AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. GRADUAL STRENGTHENING IS EXPECTED OVER THE NEXT COUPLE OF DAYS. NUMEROUS STRONG CONVECTION IS CURRENTLY IMPACTING THE NRN WINDWARDS ISLANDS FROM 14N-17N BETWEEN 58W-62W. SCATTERED MODERATE/STRONG CONVECTION IS ELSEWHERE FROM 14N-20N BETWEEN 56W-63W. TOTAL RAINFALL AMOUNTS OF 2-4 INCHES ARE EXPECTED OVER THE NRN LEEWARD ISLANDS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 1ON22W TO 4N25W MOVING W 10-15 KT. EVEN THOUGH THE WAVE IS DIFFICULT TO DISCERN IN SATELLITE IMAGERY...LOW-LEVEL STREAMLINE ANALYSIS CONTINUES TO SHOW CYCLONIC FLOW AROUND THE AXIS. NO SIGNIFICANT DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 15N17W TO 12N19W. DUE TO THE SERIES OF TROPICAL FEATURES ACROSS THE ATLC...NO OTHER PORTIONS OF THE MONSOON TROUGH OR ITCZ EXIST. AS THESE SYSTEMS MOVE WWD THE MONSOON TROUGH SHOULD BUILD BACK IN OVER THE ERN TROPICAL ATLC LATER IN THE WEEK. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL WESTERLY FLOW CONTINUES DOMINATING ACROSS THE GULF THIS EVENING BETWEEN AN UPPER LEVEL LOW CENTERED OVER THE GREAT LAKES REGION NEAR 42N87W AND AN UPPER LEVEL RIDGE CENTERED OVER THE YUCATAN PENINSULA AND NW CARIBBEAN. WATER VAPOR IMAGERY DEPICT A MODERATELY DRY AIRMASS IN PLACE ACROSS THE GULF N OF 26N. AT THE SURFACE...RIDGING FROM A 1017 MB HIGH CENTERED NEAR 27N90W IS PRODUCING LIGHT WINDS OF 10-15 KTS N OF 23N. A WEAKNESS WITHIN THE RIDGE...IS ANALYZED AS A SURFACE TROUGH CROSSING THE FLORIDA PENINSULA NE-SW AND EXTENDING INTO THE GULF FROM 25N81W TO 24N82W. OVER THE SW GULF WATERS...SHOWERS ARE BEING GENERATED ASSOCIATED TO A REGION OF HIGH MOISTURE FROM 18N-23N BETWEEN 92W-96W. ELSEWHERE IN THE GULF CLEAR SKIES AND FAIR WEATHER REMAIN. EXPECT IN THE NEXT 24 HOURS SIMILAR CONDITIONS TO PREVAIL AS THE HIGH AND ASSOCIATED RIDGE IS FORECAST TO REMAIN QUASI-STATIONARY OVER THE CENTRAL GULF. CARIBBEAN SEA... THE UPPER LEVEL RIDGE CENTERED OVER THE YUCATAN PENINSULA AND NW CARIBBEAN EXTENDS ALL THE WAY TO THE CENTRAL CARIBBEAN PROVIDING THE REGION W OF 67W WITH NORTHEAST TO EASTERLY FLOW ALOFT. THIS IS MAINTAINING MOSTLY FAIR WEATHER CONDITIONS AND CLEAR SKIES...EXCEPT FOR LA HISPANIOLA...CUBA AND JAMAICA THAT ARE EXPERIENCING SHOWERS MOSTLY DUE TO DIURNAL HEATING. BETWEEN LA HISPANIOLA AND THE LESSER ANTILLES AN UPPER LEVEL TROUGH EXTENDS DOWN TO 14N. A MASS OF DRY AIR IS CONTAINED WITHIN THIS TROUGH PROVIDING FAIR WEATHER TO PUERTO RICO AND THE EASTERN CARIBBEAN W OF 63W. THE NORTHERN LESSER ANTILLES ARE UNDER THE INFLUENCE OF THE MOISTURE ASSOCIATED TO THE REMNANTS OF OPHELIA THAT HAVE REDEVELOPED INTO A TROPICAL DEPRESSION. IN THE SOUTHERN CARIBBEAN THE MONSOON TROUGH AXIS EXTENDS FROM NORTHERN COLOMBIA NEAR 9N73W CROSSING PANAMA NEAR 9N79W AND THEN ENTERING SE NICARAGUA NEAR 11N84W. THIS FLOW ASSOCIATED TO THE MONSOON IS GENERATING ISOLATED SCATTERED SHOWERS OVER CENTRAL AMERICA. ATLANTIC OCEAN... A SHORTWAVE UPPER LEVEL TROUGH EXTENDING FROM A LONGWAVE TROUGH OVER THE ERN CONUS IS PROVIDING A REGION OF DIFFLUENT FLOW OVER THE FAR WRN ATLC. THIS IS HELPING PRODUCE SCATTERED SHOWERS/THUNDERSTORMS FROM 29N-32N BETWEEN 74W-78W...AND ISOLATED SHOWERS FROM 22N-29N BETWEEN 74W-78W. A NARROW UPPER LEVEL RIDGE IS TO THE IMMEDIATE E SANDWICHED BETWEEN THE AFOREMENTIONED UPPER TROUGH AND AN UPPER LEVEL TROUGH TO THE E THAT EXTENDS ALONG 30N69W TO THE VIRGIN ISLANDS AND INTO THE ERN CARIBBEAN. DIFFLUENT FLOW AROUND THE E SIDE OF THE TROUGH IS SUPPORTING POSSIBLE ISOLATED SHOWERS FROM 26N-30N BETWEEN 65W-69W. THE UPPER TROUGH IS ALSO PRODUCING SOME SLIGHT SWLY SHEAR ACROSS WHAT IS NOW T.D. OPHELIA. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. AN UPPER LEVEL RIDGE COVERS THE CENTRAL ATLC CENTERED NEAR 25N53W SUPPORTING A SURFACE RIDGE AROUND A 1018 MB HIGH NEAR 32N67W. AN ELONGATED UPPER LEVEL TROUGH EXTENDS FROM NEAR 31N25W TO 17N48W SUPPORTING A SERIES OF SURFACE TROUGHS. THE FIRST IS ALONG 29N40W TO 22N49W WITH POSSIBLE ISOLATED SHOWERS ALONG THE AXIS. THE SECOND IS ALONG 32N43W TO 27N51W ALSO SUPPORTING POSSIBLE ISOLATED SHOWERS. TO THE S...A SURFACE TROUGH EXTENDS ALONG 14N46W TO 10N52W...REMNANTS OF A TROPICAL WAVE. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE AXIS. THE TROUGH IS ASSOCIATED WITH AN AREA OF MODERATE MOISTURE BETWEEN T.S. PHILIPPE AND T.D. OPHELIA. THE TROUGH IS EXPECTED TO DRIFT WNW BEFORE DISSIPATING LATER IN THE WEEK. THE FAR ERN ATLC IS COVERS BY AN UPPER LEVEL TROUGH CENTERED NEAR 13N32W WITH AXIS EXTENDING NE ACROSS THE CANARY ISLANDS. THE UPPER RIDGE SUPPORTS A SURFACE RIDGE AROUND A 1019 MB HIGH NEAR 27N25W...AND A 1021 MB HIGH NEAR 34N15W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON/RAMOS