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| #200924 (Received by flhurricane at: 5:08 AM 14.Jul.2008) TCDAT2 TROPICAL STORM BERTHA DISCUSSION NUMBER 45 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008 500 AM EDT MON JUL 14 2008 BERTHA IS FINALLY...TRULY ON THE MOVE...AND THE INITIAL MOTION ESTIMATE IS NOW 335/7. THE CONVECTION HAS ALSO PERKED UP A BIT WITHIN THE PAST FEW HOURS...EVEN IN THE SHORT TIME SINCE THE DVORAK INTENSITY ESTIMATES WERE MADE AT 06Z...SO THE ADVISORY INTENSITY REMAINS ON THE HIGH END OF THOSE ESTIMATES AT 55 KT. RADAR IMAGERY FROM BERMUDA SHOWS THAT OUTER BANDS OF BERTHA HAVE BEGUN PASSING OVER THAT ISLAND...AND THE PRIMARY BAND OF CONVECTION THAT WRAPS AROUND FROM THE EAST TO THE NORTHWEST OF THE CENTER IS NOT FAR OFFSHORE. IT APPEARS THAT THE CENTER OF BERTHA WILL PASS VERY CLOSE TO THE EAST OF BERMUDA LATER TODAY...CLOSE ENOUGH TO BRING TROPICAL STORM CONDITIONS TO THAT ISLAND. GIVEN THE SPRAWLING NATURE OF THE SYSTEM...SIGNIFICANT CHANGES IN STRENGTH DO NOT APPEAR LIKELY TODAY. THE INTENSITY MODEL CONSENSUS ALSO SUGGESTS LITTLE CHANGE DURING THE NEXT SEVERAL DAYS...ALTHOUGH THE GFDL AND HWRF STILL FORECAST BERTHA TO REGAIN HURRICANE STATUS. BERTHA HAS MADE NORTHWARD PROGRESS FASTER THAN PREVIOUSLY FORECAST...AND THE TRACK HAS BEEN SPED UP A LITTLE THROUGH 48 HOURS. ONCE BERTHA ROUNDS THE RIDGE CURRENTLY TO ITS EAST AND STARTS HEADING EASTWARD AHEAD OF THE NEXT MID-LATITUDE TROUGH...THE STEERING MECHANISMS BECOME COMPLICATED DUE TO A CUTOFF LOW FORECAST TO APPROACH BERTHA FROM THE EAST. THE INTERACTION BETWEEN THE TWO CYCLONIC CIRCULATIONS COULD RESULT IN AN UNDULATING BUT GENERALLY EASTWARD TRACK OF BERTHA AS INDICATED BY ALL OF THE DYNAMICAL MODELS. AS IN THE PREVIOUS OFFICIAL FORECAST...THE NEW TRACK INCLUDES THESE UNDULATIONS...BUT SMOOTHS THROUGH THEM JUST A LITTLE. THE NEW FIVE-DAY POINT HAS ALSO BEEN SPED UP TOWARD THE MODEL CONSENSUS THAT SUGGESTS BERTHA WILL ACCELERATE OVER THE NORTHERN ATLANTIC A LITTLE MORE THAN FORECAST IN PREVIOUS MODEL RUNS. FORECAST POSITIONS AND MAX WINDS INITIAL 14/0900Z 31.5N 63.6W 55 KT 12HR VT 14/1800Z 32.6N 63.9W 55 KT 24HR VT 15/0600Z 34.2N 63.5W 60 KT 36HR VT 15/1800Z 35.8N 62.6W 55 KT 48HR VT 16/0600Z 36.4N 61.5W 55 KT 72HR VT 17/0600Z 35.0N 59.5W 50 KT 96HR VT 18/0600Z 34.5N 55.5W 50 KT 120HR VT 19/0600Z 37.5N 51.0W 50 KT $$ FORECASTER KNABB |
