Official Discussion issued by the National Hurricane Center
IKE (AL092008) DATA RELEASED: 9/2/2008 9:00:00 PM UTC
Copy of official data TROPICAL STORM IKE DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008 500 PM EDT TUE SEP 02 2008 AFTER LOOKING CONVECTIVELY ASYMMETRIC THIS MORNING...IKE HAS WRAPPED A BAND OF DEEP CONVECTION MOST OF THE WAY AROUND THE CENTER EXCEPT FOR SMALL BREAK OVER THE SOUTHERN QUADRANT. CONSEQUENTLY... DVORAK T-NUMBERS HAVE RISEN TO 3.5 FROM BOTH TAFB AND SAB SO THE INITIAL INTENSITY IS SET AT 55 KT BASED ON THE IMPROVED STRUCTURE. IKE CONTINUES TO CHUG ALONG WITHIN THE TRADES AT 280/15. THE MID-LEVEL HIGH THAT IS CENTERED NORTH-NORTHEAST OF IKE...STEERING IT WESTWARD...IS EXPECTED TO BUILD INTO THE WEST ATLANTIC AND RESULT IN VERY LITTLE POLEWARD MOTION IN THE COMING DAYS. ALTHOUGH MOST OF THE MODEL GUIDANCE REMAINS CLUSTERED THROUGH DAY 5...THE MOST NOTABLE CHANGE FROM THIS MORNING IS THE TRACK OF THE UKMET... WHICH CURVES IKE TO THE NORTHWEST NEAR 65W IN RESPONSE TO A WEAKER WEST ATLANTIC RIDGE. THE OFFICIAL FORECAST DISREGARDS THE UKMET AND FOLLOWS A CONSENSUS OF THE OTHER MODELS...SHOWING A SLIGHT SOUTH-OF-DUE-WEST MOTION IN ABOUT 48-72 HOURS. IT SHOULD BE NOTED THAT THE EXACT STEERING REGIME AT DAY 5 REMAINS HIGHLY UNCERTAIN... AND THE OFFICIAL FORECAST RECONCILES THIS BY SHOWING A MORE OR LESS WESTWARD TRACK WITHIN THE GUIDANCE ENVELOPE. THE INTENSITY GUIDANCE IS FAIRLY AGREEABLE IN THE SHORT-TERM... BRINGING IKE TO A HURRICANE WITHIN ABOUT 12 HOURS. BEYOND THAT...THE STATISTICAL-DYNAMICAL MODELS ARE A BIT RESERVED AND SHOW PEAK INTENSITIES OF 70-80 KT BEFORE MODEST NORTHEASTERLY SHEAR SETS IN BY 48 HOURS. THE HWRF MODEL IS WELL ABOVE ALL THE OTHER GUIDANCE AND IN GENERAL ITS SOLUTION IS NOT COUNTED AT THIS TIME. STILL...THERE APPEARS TO BE LITTLE REASON THAT INTENSIFICATION SHOULD NOT OCCUR SO THE OFFICIAL INTENSITY FORECAST IS A LITTLE HIGHER THAN THE SHIPS AND LGEM...BUT IN LINE WITH THE INTENSITY CONSENSUS AND NEAR THE GFDL. FORECAST POSITIONS AND MAX WINDS INITIAL 02/2100Z 19.2N 46.3W 55 KT 12HR VT 03/0600Z 19.6N 48.6W 65 KT 24HR VT 03/1800Z 20.3N 51.8W 70 KT 36HR VT 04/0600Z 21.0N 55.0W 75 KT 48HR VT 04/1800Z 21.6N 57.8W 80 KT 72HR VT 05/1800Z 22.0N 63.5W 85 KT 96HR VT 06/1800Z 21.5N 69.5W 90 KT 120HR VT 07/1800Z 21.5N 75.0W 95 KT $$ FORECASTER BERG/KNABB |