|
Show Selection: |
| #200085 (Received by flhurricane at: 10:55 AM 09.Jul.2008) TCDAT2 HURRICANE BERTHA DISCUSSION NUMBER 26 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008 1100 AM EDT WED JUL 09 2008 BERTHA'S CLOUD PATTERN HAS IMPROVED THIS MORNING AND THE EYE APPEARS TO BE REFORMING. THE INITIAL INTENSITY REMAINS 65 KT BASED ON 1200Z DVORAK CLASSIFICATIONS BUT BERTHA LOOKS TO BE IN THE PROCESS OF STRENGTHENING. THE INTENSITY FORECAST CONTINUES TO BE CHALLENGING. IN THE SHORT-TERM...THE ATMOSPHERE APPEARS FAVORABLE FOR STRENGTHENING AND THE OCEAN IS PLENTY WARM. HOWEVER...THE VARIOUS INTENSITY MODELS ARE NOT IN GOOD AGREEMENT ON HOW MUCH OR EVEN WHEN REINTENSIFICATION MIGHT OCCUR. GIVEN THE CURRENT TREND IN THE SATELLITE PRESENTATION...THE OFFICIAL FORECAST ASSUMES SOONER RATHER THAN LATER AND SHOWS BERTHA STRENGTHENING DURING THE FIRST 24 HOURS. THEREAFTER...BERTHA WILL BE MOVING OVER WARMER WATERS BUT WITH INCREASING VERTICAL SHEAR MAKING IT UNCLEAR WHETHER INTENSIFICATION WILL CONTINUE. GIVEN THE UNCERTAINTY...THE OFFICIAL FORECAST CONTINUES THE PREVIOUSLY SHOWN TREND OF SLOW WEAKENING. AS THE ABOVE SHOWS...THERE IS CONSIDERABLE UNCERTAINTY IN THE INTENSITY FORECAST. THE INITIAL MOTION IS ESSENTIALLY UNCHANGED FROM THE PREVIOUS PACKAGE...300/10. BERTHA SHOULD CONTINUE A SLOW TURN NORTHWARD DURING THE NEXT 2-3 DAYS AS A MID-TROPOSPHERIC ANTICYCLONE CURRENTLY NEAR BERMUDA IS FORECAST TO WEAKEN AND A 500 MB SHORTWAVE TROUGH MOVES OFF OF THE U.S. EAST COAST. BEYOND 72 HOURS...THE TRACK BECOMES A LITTLE LESS CERTAIN AS THE SHORTWAVE IS NOT CURRENTLY FORECAST TO PICK UP THE CYCLONE. RATHER...IT LEAVES BERTHA BEHIND IN WEAK STEERING CURRENTS POSSIBLY RESULTING IN SLOW AND ERRATIC MOTION AT THE END OF THE FORECAST. TRACK MODELS HAVE NOT DEMONSTRATED GOOD RUN TO RUN CONSISTENCY. AS A RESULT...THE NEW OFFICIAL TRACK FORECAST IS ESSENTIALLY UNCHANGED AND LIES WEST OF THE DYNAMICAL MODEL CONSENSUS. IT IS STILL TOO EARLY TO KNOW WHETHER BERTHA WILL HAVE AN IMPACT ON BERMUDA. INTERESTS ON THAT ISLAND SHOULD CONTINUE TO MONITOR THE PROGRESS OF THIS HURRICANE OVER THE NEXT COUPLE OF DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 09/1500Z 24.2N 57.5W 65 KT 12HR VT 10/0000Z 24.7N 58.5W 70 KT 24HR VT 10/1200Z 25.9N 59.7W 75 KT 36HR VT 11/0000Z 27.2N 60.6W 75 KT 48HR VT 11/1200Z 28.3N 61.1W 70 KT 72HR VT 12/1200Z 30.0N 61.5W 70 KT 96HR VT 13/1200Z 31.5N 61.5W 65 KT 120HR VT 14/1200Z 33.5N 60.5W 60 KT $$ FORECASTER RHOME |
