Official Discussion issued by the National Hurricane Center
IKE (AL092008) DATA RELEASED: 9/4/2008 3:00:00 AM UTC
Copy of official data HURRICANE IKE DISCUSSION NUMBER 12 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008 1100 PM EDT WED SEP 03 2008 IKE HAS RAPIDLY INTENSIFIED THIS EVENING. AN EYE BECAME APPARENT IN CONVENTIONAL SATELLITE IMAGERY SHORTLY AFTER 2100 UTC. SINCE THAT TIME THE EYE HAS BECOME MORE DISTINCT WITH A RING OF VERY COLD CLOUDS TOPS SURROUNDING IT. THE LATEST DVORAK DATA T-NUMBERS WERE T6.0 AND RAW ADT ESTIMATES FROM UW-CIMSS HAVE AVERAGED T6.2 SINCE 2045 UTC. BASED ON THESE ESTIMATES THE INITIAL INTENSITY IS SET AT 115 KT...MAKING IKE A CATEGORY FOUR HURRICANE. SOME ADDITIONAL STRENGTHENING IS POSSIBLE DURING THE NEXT 12 HOURS OR SO...THIS WILL LARGELY BE CONTROLLED BY EYE-WALL REPLACEMENT CYCLES. HOWEVER BOTH THE GLOBAL MODELS AND SHIPS GUIDANCE INDICATE INCREASING NORTHEASTERLY SHEAR IN ABOUT 24 HOURS AND IT IS DIFFICULT TO PREDICT HOW AN INTENSE HURRICANE LIKE IKE WILL BE AFFECTED BY THIS SHEAR. THE NHC INTENSITY FORECAST INDICATES SOME WEAKENING BETWEEN 24-72 HOURS DUE TO THE SHEAR...BUT NOT AS MUCH AS INDICATED BY THE SHIPS GUIDANCE. AT DAYS 4 AND 5...IT APPEARS THAT THE SHEAR WILL DECREASE SO RE-STRENGTHENING IS PREDICTED AT THAT TIME. THE INITIAL MOTION ESTIMATE IS 295/15. THE TRACK GUIDANCE AGREES ON A CONTINUED WEST-NORTHWESTWARD MOTION DURING THE NEXT 24 HOURS. DURING THE MIDDLE PORTION OF THE FORECAST PERIOD...A MID-LEVEL RIDGE IS EXPECTED TO BUILD TO THE NORTH OF THE CYCLONE...AND THE MODELS UNANIMOUSLY RESPOND BY TURNING IKE WEST-SOUTHWESTWARD. THE LINGERING QUESTION THAT REMAINS AT THE LONGER RANGE IS WHEN IKE WILL MOVE AROUND THE WESTERN PERIPHERY OF THE RIDGE. THE MODEL SPREAD REMAINS QUITE LARGE AT DAYS 4 AND 5. THE GFDL IS ON THE LEFT SIDE OF THE GUIDANCE WITH A TRACK NEAR HISPANIOLA AND EASTERN CUBA...WHILE THE GFS AND UKMET SHOW A POSITION TO THE NORTHEAST OF THE BAHAMAS. FOR NOW...THE OFFICIAL TRACK IS BETWEEN THESE POSSIBLE SOLUTIONS AND IS IN BEST AGREEMENT WITH THE HWRF...THE 12Z ECMWF...AND THE MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 04/0300Z 22.1N 54.1W 115 KT 12HR VT 04/1200Z 23.1N 56.2W 115 KT 24HR VT 05/0000Z 24.0N 58.7W 105 KT 36HR VT 05/1200Z 24.3N 61.0W 105 KT 48HR VT 06/0000Z 23.8N 63.6W 100 KT 72HR VT 07/0000Z 22.5N 68.5W 100 KT 96HR VT 08/0000Z 22.5N 72.0W 110 KT 120HR VT 09/0000Z 24.0N 75.5W 115 KT $$ FORECASTER BROWN |