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| #45920 (Received by flhurricane at: 11:00 AM 14.Sep.2005) TCDAT1 HURRICANE OPHELIA DISCUSSION NUMBER 34 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT WED SEP 14 2005 DATA FROM AN AIR FORCE RECONNAISSANCE PLANE AND NOAA LAND-BASED DOPPLER RADARS FROM WILMINGTON AND MOREHEAD CITY INDICATE THAT THE INTENSITY HAS INCREASED TO 70 KT BASED ON 700 MB FLIGHT-LEVEL WINDS OF 80 KT IN THE SOUTHEAST QUADRANT AND DOPPLER VELOCITIES OF 86-91 THAT EXTENDED FROM 2500-8000 FT. THE ORGANIZATION HAS CONTINUED TO IMPROVE IN RADAR AND SATELLITE IMAGERY...DESPITE THE VERY LARGE 50 NMI DIAMETER EYE. OUTFLOW IS EXCELLENT IN ALL QUADRANTS. THE INITIAL MOTION IS 030/06. RECENT 12Z UPPER-AIR DATA AND WATER VAPOR SATELLITE IMAGERY INDICATES THE RIDGE TO THE NORTH AND WEST OF OPHELIA HAS WEAKENED...WHEREAS THE RIDGE TO THE SOUTH OF THE HURRICANE HAS STRENGTHENED. THE COMBINATION OF THE RIDGING TO THE SOUTH AND AN APPROACHING SHORTWAVE TROUGH FROM THE WEST SHOULD ACT TO KEEP OPHELIA MOVING IN A GENERAL NORTH-NORTHEAST TO NORTHEASTWARD MOTION FOR THE NEXT 24-36 HOURS. THIS SHOULD BRING THE CENTER OF THE LARGE EYE OVER OR JUST SOUTH OF THE NORTH CAROLINA OUTER BANKS BY 24 HOURS...AND CLEARING THE OUTER BANKS BY 36 HOURS. THE VARIOUS NHC MODELS ARE IN FAIR AGREEMENT ON THIS SCENARIO. AFTER THAT...HOWEVER...THE MODELS DIVERGE SIGNIFICANTLY WITH THE NOGAPS...UKMET...CANADIAN AND ECMWF MODELS STALL OPHELIA NEAR THE OUTER BANKS IN 36-48 HOURS...AND THEN MOVE THE HURRICANE NORTH-NORTHEASTWARD OVER OR JUST SOUTHEAST OF THE CAPE COD AREA. IN CONTRAST... THE GFS...GFS ENSEMBLE...AND GFDL MODELS KEEP OPHELIA WELL OFFSHORE AND MOVING RAPIDLY NORTHEASTWARD THROUGHOUT THE PERIOD IN DEEP-LAYER WEST-SOUTHWESTERLY STEERING FLOW. THE LATTER SCENARIO IS PREFERRED AT THIS TIME GIVEN THE CURRENT PROGRESSIVE SYNOPTIC-SCALE FLOW PATTERN AND VIGOROUS UPSTREAM SHORTWAVE TROUGH. THE SHEAR IS FORECAST TO REMAIN LOW AND THE OUTFLOW WILL INCREASE TO THE NORTH DURING THE NEXT 24-36 HOURS. GIVEN THAT THERE IS STILL ENOUGH RELATIVELY WARM WATER BENEATH THE HURRICANE...SOME SLIGHT STRENGTHENING IS STILL POSSIBLE BEFORE LANDFALL OCCURS... ESPECIALLY IF THE EYE REMAINS MORE OVER THE WATER THAN OVER LAND. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 14/1500Z 33.7N 77.6W 70 KT 12HR VT 15/0000Z 34.5N 76.9W 75 KT 24HR VT 15/1200Z 35.1N 75.9W 75 KT...NEAR OUTER BANKS 36HR VT 16/0000Z 35.8N 74.5W 70 KT 48HR VT 16/1200Z 36.8N 72.5W 65 KT 72HR VT 17/1200Z 39.6N 68.0W 60 KT 96HR VT 18/1200Z 45.0N 58.0W 50 KT...EXTRATROPICAL 120HR VT 19/1200Z 49.0N 45.0W 45 KT...EXTRATROPICAL |
