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| #213014 (Received by flhurricane at: 10:56 PM 02.Sep.2008) TCDAT4 TROPICAL STORM IKE DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008 1100 PM EDT TUE SEP 02 2008 THE OVERALL CLOUD PATTERN IS A LITTLE MORE SYMMETRIC AND THE OUTFLOW IS EXCELLENT IN ALL QUADRANTS. HOWEVER...IKE LACKS AN INNER CORE AND DEEP CONVECTION IS LIMITED TO A CYCLONICALLY CURVED BAND MAINLY TO THE WEST OF THE CENTER. AN EARLIER QUIKSCAT PASS DID NOT SHOW ANY WINDS HIGHER THAN 45 KNOTS BUT DVORAK T-NUMBERS CONTINUE TO SUGGEST THAT THE WINDS ARE 55 KNOTS..AND THIS NUMBER IS USED FOR THE INITIAL INTENSITY. SINCE THE SHEAR IS EXPECTED TO BE LIGHT FOR A DAY OR SO...A GRADUAL INTENSIFICATION IS FORECAST AND IKE COULD BECOME A HURRICANE ANYTIME SOON. IN 2 TO 3 DAYS... A STRONG EASTERLY SHEAR IS FORECAST TO DEVELOP AND COULD DELAY THE INTENSIFICATION PROCESS. HOWEVER...EASTERLY SHEAR IS NOT AS NEGATIVE AS WESTERLY SHEAR FOR A CYCLONE TO INTENSIFY. ALTHOUGH BOTH GFDL AND HWRF MAKE IKE AN INTENSE CYCLONE IN THE VICINITY OF THE BAHAMAS IN FIVE DAYS...THE OFFICIAL FORECAST IS MORE MODERATE...AND IS A BLEND OF THE SHIPS AND THE DYNAMICAL MODELS. IKE IS SOUTH OF A STRONG SUBTROPICAL RIDGE AND IS MOVING TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 15 KNOTS. GLOBAL MODELS EXPAND AND BUILD THE RIDGE WESTWARD...AND THIS PATTERN SHOULD FORCE IKE ON A GENERAL WESTWARD TRACK. THE RIDGE BECOMES SO STRONG BY THE END OF THE FORECAST PERIOD THAT MODELS TURN IKE ON A SLIGHT WEST-SOUTHWEST TRACK. THIS SHIFT IS REFLECTED IN THE OFFICIAL FORECAST. WITH THE EXCEPTION OF THE UK MODEL...WHICH MOVES IKE WITH A MORE WEST-NORTHWEST TRACK...THE REST OF THE GUIDANCE IS TIGHTLY CLUSTERED PLACING THE CYCLONE IN THE SOUTH/CENTRAL BAHAMAS IN FIVE DAYS. THE FACT THAT MOST OF THE DYNAMICAL MODELS ARE IN GOOD AGREEMENT INCREASES THE CONFIDENCE IN THE TRACK FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 03/0300Z 19.9N 47.9W 55 KT 12HR VT 03/1200Z 20.3N 50.3W 65 KT 24HR VT 04/0000Z 21.0N 53.5W 70 KT 36HR VT 04/1200Z 22.0N 56.5W 75 KT 48HR VT 05/0000Z 22.5N 59.5W 80 KT 72HR VT 06/0000Z 22.5N 64.5W 85 KT 96HR VT 07/0000Z 22.5N 70.0W 90 KT 120HR VT 08/0000Z 22.1N 76.0W 95 KT $$ FORECASTER AVILA |
