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#45748 (Received by flhurricane at: 5:00 PM 13.Sep.2005) TCDAT1 TROPICAL STORM OPHELIA DISCUSSION NUMBER 30 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT TUE SEP 13 2005 DATA FROM SATELLITES...NOAA COASTAL DOPPLER RADARS...AND AN AIR FORCE RECONNAISSANCE AIRCRAFT INDICATE OPHELIA HAS CONTINUED TO SLOWLY BECOME BETTER ORGANIZED AS INNER CORE CONVECTION HAS INCREASED IN BOTH COVERAGE AND INTENSITY. THE HIGHEST RECON 700 MB FLIGHT-LEVEL HAS BEEN 76 KT IN THE NORTHWEST QUADRANT...AND DOPPLER VELOCITY DATA FROM WILMINGTON HAS BEEN AS HIGH AS 80 KT AT 9900 FEET IN THE NORTHWEST QUADRANT. THESE VALUES WOULD NORMALLY SUPPORT 68-72 KT SURFACE WINDS AND MAKE OPHELIA A HURRICANE. HOWEVER... THESE HIGHER-LEVEL WIND VALUES HAVE BEEN OBSERVED VERY CLOSE TO NOAA BUOY 41004...WHICH HAS ONLY BEEN REPORTING SUSTAINED WINDS OF 43 KT. SINCE THE CENTRAL PRESSURE HAS NOT DECREASED DURING THE DAY ...THE INITIAL INTENSITY IS BEING MAINTAINED AT 60 KT...ALTHOUGH THERE MAY SOME LOCALIZED SMALL PATCHES OF HURRICANE-FORCE WINDS BENEATH THE STRONGER WINDS ALOFT. THE INITIAL MOTION ESTIMATE IS 345 DEGREES AT 3-4 KT OVER THE PAST 12 HOURS. THE INNER CORE WIND FIELD AND CONVECTION HAS TIGHTENED UP SOMEWHAT SINCE THIS MORNING AND THERE HAS BEEN LESS WOBBLE ALONG THE NORTH-NORTHWEST TRACK. WATER VAPOR IMAGERY INDICATES THE MID-LEVEL RIDGE AXIS OVER THE NEW ENGLAND STATES HAS CONTINUED TO MOVE GRADUALLY EASTWARD...WHILE 18Z SPECIAL UPPER-AIR DATA FROM THE CAROLINAS INDICATES THE SOUTHERN PORTION OF THE RIDGE HAS NOT ERODED AS QUICKLY AS THE 12Z GLOBAL MODELS WERE FORECASTING. AS A RESULT...THE OFFICIAL FORECAST IS A LITTLE TO THE LEFT OF THE MODEL CONSENSUS THROUGH 24 HOURS...AND THEN A LITTLE TO THE RIGHT OF THE GUIDANCE AFTER 72 HOURS AS WESTERLY MID-LEVEL FLOW IS EXPECTED TO DRIVE OPHELIA MORE TO THE EAST AT HIGHER LATITUDES BY DAYS 4 AND 5. THE LARGE INNER-CORE WIND FIELD AND RELATIVELY COOL SSTS SHOULD PREVENT SIGNIFICANT STRENGTHENING FROM OCCURRING. HOWEVER...THE UPPER-LEVEL OUTFLOW IS EXPECTED TO REMAIN FAVORABLE FOR THE NEXT 48 HOURS...SO SOME MODEST STRENGTHENING IS STILL POSSIBLE AND OPHELIA COULD PEAK AT 70 KT BEFORE LANDFALL OCCURS. AFTER OPHELIA CLEARS THE NORTH CAROLINA OUTER BANKS...INCREASING WESTERLY SHEAR SHOULD CAUSE SLOW WEAKENING UNTIL OPHELIA TRANSITIONS INTO A FORMIDABLE EXTRATROPICAL LOW PRESSURE SYSTEM OVER THE NORTH ATLANTIC. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 13/2100Z 32.6N 78.1W 60 KT 12HR VT 14/0600Z 33.3N 77.8W 65 KT 24HR VT 14/1800Z 34.3N 77.2W 65 KT 36HR VT 15/0600Z 35.2N 76.1W 65 KT...INLAND/PAMLICO SOUND 48HR VT 15/1800Z 35.7N 74.7W 65 KT...OVER WATER 72HR VT 16/1800Z 37.8N 70.7W 60 KT 96HR VT 17/1800Z 42.5N 62.5W 55 KT...EXTRATROPICAL 120HR VT 18/1800Z 48.5N 49.5W 45 KT...EXTRATROPICAL |