Official Discussion issued by the National Hurricane Center
IKE (AL092008) DATA RELEASED: 9/9/2008 3:00:00 AM UTC
Copy of official data HURRICANE IKE DISCUSSION NUMBER 32 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008 1100 PM EDT MON SEP 08 2008 THE LAST AIR FORCE HURRICANE HUNTER PENETRATION OF IKE'S EYE INDICATED THAT THERE WAS A CLOSED WALL AND SATELLITE IMAGERY SHOWS COLD TOPS DEVELOPING VERY NEAR THE CENTER. THERE HAD BEEN LITTLE CHANGE IN THE CENTRAL PRESSURE OVER THE LAST FEW AIRCRAFT FIXES. THE CURRENT INTENSITY IS KEPT AT 70 KT EVEN THOUGH THERE WERE NO RECENT FLIGHT-LEVEL WINDS TO SUPPORT THIS VALUE. SURFACE WINDS AS HIGH AS 74 KT WERE REPORTED FROM THE SFMR INSTRUMENT ON BOARD THE AIRCRAFT...BUT THOSE DAD THE AIRCRAFT...BUT THOSE DATA THE AIRCRAFT...BUT THOSE DATA WERE QUESTIONABLE. SINCE THE INNER CORE APPEARS TO BE REDEVELOPING...SOME STRENGTHENING COULD OCCUR AS LONG AS THE CENTER REMAINS OFFSHORE OF THE SOUTH COAST OF CUBA. AFTER IKE MOVES INTO THE GULF OF MEXICO...GLOBAL MODELS SUGGEST A FAVORABLE LARGE-SCALE UPPER-LEVEL WIND PATTERN WITH BROAD ANTICYCLONIC FLOW AND SOME EVIDENCE OF OUTFLOW CHANNELS OVER THE EASTERN PORTION OF THE TROPICAL CYCLONE'S CIRCULATION. THE OFFICIAL 3- TO 4 DAY INTENSITY FORECAST COULD BE CONSERVATIVE...BUT WE HAVE LITTLE SKILL IN INTENSITY PREDICTION AT THESE TIME RANGES. AFTER WOBBLING A BIT TO THE NORTHWEST AND ALMOST MOVING ASHORE ON THE SOUTH COAST OF CUBA...THE MOTION HAS SHIFTED BACK TO THE WEST-NORTHWEST OR 290/11 AND IKE IS MOVING ROUGHLY PARALLEL TO...AND JUST OFFSHORE OF...THE COAST. THE TRACK MODELS ARE IN VERY CLOSE AGREEMENT ON THE MOTION OF IKE OVER THE NEXT COUPLE OF DAYS. IN 3-5 DAYS...THE GUIDANCE SPREADS OUT SOMEWHAT. THE GLOBAL MODELS DEPICT A PRONOUNCED MID-TROPOSPHERIC RIDGE OVER THE NORTHERN GULF COAST IN THE LATTER PART OF THE FORECAST PERIOD. THE GFS AND ITS ENSEMBLE MEAN...ALONG WITH THE NOGAPS...SHOW THAT THIS RIDGE WILL BE STRONG ENOUGH TO CAUSE IKE TO TURN TOWARD THE WEST IN 96-120 HOURS. SOME OF THE GUIDANCE SUCH AS THE HWRF AND GFDL INDICATE THAT A SHORT WAVE TROUGH MOVING FROM THE ROCKIES WILL ERODE THE RIDGE ENOUGH TO INDUCE A MORE NORTHWARD TURN NEAR THE END OF THE PERIOD. I AM FAVORING THE MORE WESTWARD OPTION AT THIS TIME SINCE IT WOULD SEEM THAT THE GFDL AND HWRF...WHICH ARE REGIONAL MODELS...WOULD NOT HANDLE THE EVOLUTION OF MID-LATITUDE SHORT WAVE TROUGHS AS WELL AS A GLOBAL MODEL. THE OFFICIAL TRACK FORECAST IS SHIFTED SOUTHWARD FROM THE PREVIOUS ONE AT DAYS 4 AND 5 BUT IS STILL GENERALLY NORTH OF THE DYNAMICAL TRACK MODEL CONSENSUS. AS ALWAYS...IT CANNOT BE OVEREMPHASIZED THAT ONE SHOULD NOT FOCUS ON 4 AND 5 DAY FORECAST POINTS SINCE THESE CAN BE SUBJECT TO SUBSTANTIAL ERRORS. FORECAST POSITIONS AND MAX WINDS INITIAL 09/0300Z 21.8N 80.8W 70 KT 12HR VT 09/1200Z 22.4N 82.3W 80 KT 24HR VT 10/0000Z 23.2N 84.0W 85 KT 36HR VT 10/1200Z 24.0N 85.7W 90 KT 48HR VT 11/0000Z 24.8N 87.2W 95 KT 72HR VT 12/0000Z 26.0N 91.0W 100 KT 96HR VT 13/0000Z 27.0N 94.5W 100 KT 120HR VT 14/0000Z 28.0N 98.0W 95 KT...INLAND $$ FORECASTER PASCH/BERG |