Show Selection: |
#370949 (Received by flhurricane at: 10:46 AM 24.Aug.2010) TCDAT1 HURRICANE DANIELLE DISCUSSION NUMBER 12 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010 1100 AM AST TUE AUG 24 2010 THE PERIOD OF RAPID INTENSIFICATION HAS ENDED WITH A THUD. THE LOW-LEVEL CENTER OF DANIELLE HAS BECOME EXPOSED BETWEEN A RAGGED CENTRAL DENSE OVERCAST TO ITS EAST...AND A BROKEN CONVECTIVE BAND TO ITS WEST. ALL ALONG...MICROWAVE IMAGERY SINCE ABOUT 0300 UTC SHOWED A DRY SLOT WRAPPING AROUND THE WESTERN AND SOUTHERN SIDE OF THE CIRCULATION...AND AS A RESULT THE EYEWALL BECAME ERODED. DATA T-NUMBERS HAVE FALLEN QUICKLY AND ARE NOW AS LOW AS T3.9 FROM THE HURRICANE INTENSITY ESTIMATE...AN EXPERIMENTAL FORM OF THE UW-CIMSS ADT. THE INITIAL INTENSITY IS LOWERED TO 70 KT AT THIS TIME... WHICH COULD STILL BE GENEROUS. SHIPS GUIDANCE SHOWS WESTERLY TO SOUTHWESTERLY SHEAR INCREASING TO BETWEEN 15 AND 20 KT OVER THE NEXT 24 HOURS OR SO...AND IT IS UNCLEAR HOW WELL DANIELLE WILL BE ABLE TO MIX OUT THE DRY AIR. ONLY SLOW STRENGTHENING IS INDICATED IN THE OFFICIAL FORECAST...AND THE INTENSITY AT DAYS 4 AND 5 IS HELD JUST BELOW MAJOR HURRICANE STRENGTH TO MAINTAIN SOME SORT OF CONTINUITY...BUT THIS IS NOW ABOVE MANY OF THE INTENSITY MODELS. MICROWAVE FIXES INDICATE THAT DANIELLE HAS BEEN MOVING QUICKLY WITH AND A AN INITIAL MOTION ESTIMATE OF 290/17. THIS MOTION IS A LITTLE TO THE LEFT OF THE FORECAST TRACK. LITTLE CHANGE IS REQUIRED IN THE FORECAST...AND DANIELLE IS STILL EXPECTED TO TURN TOWARD THE NORTHWEST THROUGH A WEAKNESS IN THE SUBTROPICAL RIDGE. THE MODEL GUIDANCE REMAINS IN VERY GOOD AGREEMENT ON THIS SCENARIO. THE OFFICIAL FORECAST TRACK LIES A LITTLE WEST OF THE PREVIOUS FORECAST DURING THE NEXT 48 HOURS TO ACCOUNT FOR THE INITIAL MOTION BUT THEN REMAINS CONSISTENT WITH THE EARLIER FORECASTS FOR DAYS 3 THROUGH 5. THIS SOLUTION IS VERY CLOSE TO THE MULTI-MODEL CONSENSUS TVCN AND STILL A LITTLE LEFT OF THE GFS...GFDL...AND HWRF...WHICH SEAMS REASONABLE GIVEN THE CONTINUED LEFT-OF-TRACK MOTION. FORECAST POSITIONS AND MAX WINDS INITIAL 24/1500Z 16.6N 46.5W 70 KT 12HR VT 25/0000Z 17.5N 48.3W 75 KT 24HR VT 25/1200Z 19.1N 50.4W 80 KT 36HR VT 26/0000Z 21.0N 52.3W 85 KT 48HR VT 26/1200Z 22.8N 53.8W 90 KT 72HR VT 27/1200Z 26.0N 56.5W 90 KT 96HR VT 28/1200Z 28.5N 58.5W 95 KT 120HR VT 29/1200Z 32.0N 59.5W 95 KT $$ FORECASTER BERG |