000 WTNT41 KNHC 261440 TCDAT1 HURRICANE DANIELLE DISCUSSION NUMBER 20 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010 1100 AM AST THU AUG 26 2010 DANIELLE HAS GONE THROUGH ANOTHER ROUND OF CHANGES IN ITS CONVECTIVE STRUCTURE. THE EYE THAT WAS APPARENT FROM 05-07Z DISAPPEARED AT ABOUT 10Z...ACCOMPANIED BY AN OVERALL DECREASE IN ORGANIZATION. SINCE THEN...THE EYE HAS RE-APPEARED...EMBEDDED IN A RAGGED CENTRAL DENSE OVERCAST. SATELLITE INTENSITY ESTIMATES ARE 90 KT FROM TAFB AND SAB...SO THAT REMAINS THE INITIAL INTENSITY. HOWEVER...THIS MAY BE SMOOTHING THROUGH SOME SHORT-TERM FLUCTUATIONS. THE INITIAL MOTION IS 320/13. IN THE FIRST 48 HR OF THE FORECAST PERIOD...DANIELLE SHOULD BE STEERED GENERALLY NORTHWESTWARD BY A LOW/MID-LEVEL RIDGE PASSING TO THE NORTH AND NORTHEAST OF THE HURRICANE. AFTER THAT TIME...A LARGE MID/UPPER-LEVEL TROUGH MOVING THROUGH THE NORTHEASTERN UNITED STATES AND THE CANADIAN MARITIMES IS EXPECTED TO CAUSE DANIELLE TO TURN TOWARD THE NORTH AND THE NORTHEAST. THE GUIDANCE HAS MADE A MAJOR EASTWARD SHIFT SINCE THE PREVIOUS ADVISORY...AND IT IS NOW IN GOOD AGREEMENT ON RECURVATURE INTO THE WESTERLIES WITH AN INCREASE IN FORWARD SPEED AFTER 72 HR. THE NEW FORECAST TRACK WILL ALSO BE SHIFTED EASTWARD DURING THIS PERIOD...BUT NOT AS MUCH AS THE GUIDANCE HAS SHIFTED. THE NEW FORECAST TRACK IS DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE FOR THE FIRST 48 HR...AND IS ALONG THE LEFT EDGE OF THE GUIDANCE ENVELOPE FROM 72-120 HR. ADDITIONAL EASTWARD ADJUSTMENTS OF THE FORECAST TRACK MAY BE NECESSARY THIS AFTERNOON IF THE CURRENT TRENDS IN THE GUIDANCE CONTINUE. ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN SUGGEST THAT DANIELLE IS EXPERIENCING ABOUT 10 KT OF SOUTHWESTERLY VERTICAL WIND SHEAR. THE HURRICANE SHOULD CONTINUE IN A LIGHT/MODERATE SHEAR ENVIRONMENT FOR 48 HR OR SO BEFORE ENCOUNTERING STRONGER SHEAR ASSOCIATED WITH THE UPPER-LEVEL TROUGH. ALL INTENSITY GUIDANCE FORECAST STRENGTHENING FOR 24-48 HR AND THE INTENSITY FORECAST FOLLOWS THAT SCENARIO...WITH A PEAK INTENSITY OF 100 KT IN 24 HR. AFTER 48 HR...INCREASING SHEAR AND DECREASING SEA SURFACE TEMPERATURES SHOULD CAUSE STEADY WEAKENING. FORECAST POSITIONS AND MAX WINDS INITIAL 26/1500Z 24.4N 55.9W 90 KT 12HR VT 27/0000Z 25.3N 57.3W 95 KT 24HR VT 27/1200Z 26.5N 59.1W 100 KT 36HR VT 28/0000Z 27.8N 60.4W 100 KT 48HR VT 28/1200Z 29.3N 61.2W 100 KT 72HR VT 29/1200Z 33.0N 60.5W 95 KT 96HR VT 30/1200Z 36.5N 58.5W 85 KT 120HR VT 31/1200Z 39.0N 55.0W 70 KT $$ FORECASTER BEVEN