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| #202451 (Received by flhurricane at: 4:40 AM 22.Jul.2008) TCDAT4 TROPICAL STORM DOLLY DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042008 500 AM EDT TUE JUL 22 2008 AN AIR FORCE RESERVE UNIT HURRICANE HUNTER PLANE REPORTED THAT THE CENTRAL PRESSURE DROPPED A LITTLE...TO 997 MB. THE SFMR ON BOARD THE AIRCRAFT REPORTED WINDS NEAR 60 KT IN THE SOUTHEAST QUADRANT BUT THESE READINGS WERE IN AREAS OF HEAVY PRECIPITATION WHICH PROBABLY CAUSED SPIKES IN THE VELOCITY VALUES. ASSUMING THAT THESE WERE OVERESTIMATES BUT TAKING INTO ACCOUNT THE SLIGHTLY LOWER PRESSURE THE CURRENT INTENSITY IS ESTIMATED TO BE SLIGHTLY HIGHER...50 KT. SATELLITE IMAGERY INDICATES THAT THE TROPICAL CYCLONE IS STILL IN THE ORGANIZING STAGE WITH SOME BANDING FEATURES OVER THE WESTERN SEMICIRCLE. THERE IS A PRONOUNCED UPPER-LEVEL OUTFLOW CHANNEL EMANATING FROM THE NORTHWESTERN PART OF THE CIRCULATION THAT EXTENDS ANTICYCLONICALLY AROUND THE EASTERN SIDE OF DOLLY AND POURING SOUTHWARD INTO THE WESTERN CARIBBEAN...HOWEVER OUTFLOW IS BEING INHIBITED OVER THE SOUTHERN PART OF THE STORM BY AN UPPER-LEVEL LOW OVER THE BAY OF CAMPECHE. DYNAMICAL GUIDANCE INDICATES A MORE SYMMETRIC OUTFLOW PATTERN EVOLVING OVER THE NEXT DAY OR SO. RECENT ENHANCED IR IMAGERY SHOWS AN INCREASE IN CONVECTION NEAR/OVER THE CENTER WHICH SUGGESTS THAT FURTHER STRENGTHENING IS IMMINENT. THE OFFICIAL INTENSITY FORECAST IS VERY SIMILAR TO THE PREVIOUS ONE AND IS ABOVE THE SHIPS GUIDANCE...BUT NOT FAR FROM THE GFDL/HWRF PREDICTIONS. IT SHOULD BE NOTED THAT ONCE DOLLY ESTABLISHES AN INNER CORE...I.E. AN EYEWALL-LIKE STRUCTURE...THE RATE OF INTENSIFICATION COULD BE FAIRLY RAPID IN COMPARISON TO WHAT WE HAVE OBSERVED THUS FAR. HOWEVER...IT SEEMS UNLIKELY THAT DOLLY WOULD BECOME A MAJOR HURRICANE PRIOR TO LANDFALL. FIXES FROM THE AIRCRAFT SHOW THAT THE MOTION HAS BEEN ONLY SLIGHTLY NORTH OF DUE WEST AT A SLIGHTLY SLOWER FORWARD SPEED...OR 280/13. THE TRACK FORECAST REASONING IS BASICALLY UNCHANGED. A COUPLE OF SHORT WAVE TROUGHS MOVING THROUGH THE GREAT LAKES/OHIO VALLEY REGION ARE FORECAST TO ERODE SLIGHTLY THE PORTION OF THE MID-TROPOSPHERIC RIDGE OVER EASTERN TEXAS. AS A RESULT...THE TRACK OF DOLLY IS LIKELY TO BEND TOWARD THE NORTHWEST WITH ADDITIONAL DECELERATION OVER THE NEXT DAY OR SO. THE LATEST NHC TRACK FORECAST IS NEAR OR SLIGHTLY NORTH OF THE MODEL CONSENSUS...AND A LITTLE SOUTH OF THE LATEST GFDL/HWRF TRACKS. AGAIN IT SHOULD BE EMPHASIZED THAT...DUE TO THE INHERENT UNCERTAINTIES...ONE MUST NOT FOCUS ON THE EXACT LANDFALL POINT IN THIS FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 22/0900Z 23.3N 93.8W 50 KT 12HR VT 22/1800Z 24.1N 95.1W 55 KT 24HR VT 23/0600Z 25.0N 96.5W 65 KT 36HR VT 23/1800Z 25.7N 97.5W 75 KT...INLAND 48HR VT 24/0600Z 26.0N 99.0W 45 KT...INLAND 72HR VT 25/0600Z 26.0N 102.0W 20 KT...REMNANT LOW 96HR VT 26/0600Z...DISSIPATED $$ FORECASTER PASCH |
