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| #5603 (Received by flhurricane at: 4:46 PM 18.Aug.2004) TCDAT4 TROPICAL STORM DANIELLE DISCUSSION NUMBER 22 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT WED AUG 18 2004 SATELLITE IMAGES CONTINUE TO SHOW THAT DANIELLE IS WEAKENING DUE PRIMARILY TO SHEAR ASSOCIATED WITH A LARGE UPPER-LEVEL LOW TO ITS WEST. THE LOW LEVEL CENTER IS WELL REMOVED FROM THE CONVECTION AND THE CLOUD PATTERN HAS BECOME VERY POORLY ORGANIZED. THE CENTER OF DANIELLE PASSED NEAR A DRIFTING BUOY WHICH MEASURED ONLY 1008.6 MB. THEREFORE...THE INITIAL INTENSITY IS ADJUSTED TO 45 KNOTS AND THIS APPEARS TO BE A GENEROUS ESTIMATE. THE SHEAR IS FORECAST TO REMAIN HIGH SO WEAKENING IS EXPECTED. THIS IS CONSISTENT WITH THE SHIPS MODEL. DANIELLE HAS BEEN MOVING TOWARD THE NORTH-NORTHEAST OR 030 DEGREES AT 9 KNOTS. STEERING CURRENTS ARE COLLAPSING AND THERE IS NO CHOICE BUT TO FORECAST A REDUCTION IN FORWARD SPEED. THIS CONSISTENT WITH MOST OF THE GLOBAL MODELS WHICH ARE MOVING THE CYCLONE SLOWER THAN IN PREVIOUS RUNS. THE OFFICIAL FORECAST CALLS FOR A SLOW NORTHEASTWARD TRACK DURING THE NEXT 2 TO 3 DAYS WITH A GRADUAL INCREASE IN FORWARD SPEED THEREAFTER. ON THIS TRACK...DANIELLE WILL LIKELY BECOME EXTRATROPICAL IN 4 DAYS OR SO. ON THE OTHER HAND...IF THE CYCLONE CONTINUES TO WEAKEN AND BECOMES A SHALLOW DEPRESSION OR A REMNANT LOW...IT COULD MEANDER FOR A FEW DAYS PRODUCING INTERMITTENT BURSTS OF CONVECTION. THE LATTER IS THE SOLUTION OF THE GFS WHICH IS BY NO MEANS OUT OF THE QUESTION. FORECASTER AVILA FORECAST POSITIONS AND MAX WINDS INITIAL 18/2100Z 29.3N 38.4W 45 KT 12HR VT 19/0600Z 30.6N 38.2W 35 KT 24HR VT 19/1800Z 32.0N 37.5W 30 KT 36HR VT 20/0600Z 33.0N 36.5W 25 KT 48HR VT 20/1800Z 33.5N 35.0W 25 KT 72HR VT 21/1800Z 34.5N 32.0W 25 KT...EXTRATROPICAL 96HR VT 22/1800Z 37.0N 28.0W 25 KT...EXTRATROPICAL 120HR VT 23/1800Z 40.0N 24.0W 25 KT...EXTRATROPICAL |
