962 
 WTNT44 KNHC 110301
 TCDAT4
 HURRICANE IKE DISCUSSION NUMBER  40
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL092008
 1100 PM EDT WED SEP 10 2008
  
 OVERALL...IKE IS A LARGE CYCLONE...AS DATA FROM BOTH AIR FORCE AND
 NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT THE EXTENT OF WINDS OF
 HURRICANE AND TROPICAL STORM FORCE HAS INCREASED...ESPECIALLY NORTH
 OF THE CIRCULATION CENTER.  PARADOXICALLY...IKE HAS A VERY SMALL
 INNER CORE...AND THE EYE HAS A DIAMETER OF ONLY ABOUT 8 TO 10 N MI. 
 THE CENTRAL PRESSURE HAS BEEN STEADILY FALLING...NOW DOWN TO ABOUT
 944 MB...BUT THE WINDS HAVE NOT YET RESPONDED.  THE INITIAL
 INTENSITY REMAINS 85 KT BASED ON RECENT SFMR WIND SPEED RETRIEVALS. 
 THE SHORT-TERM INTENSITY FORECAST IS CONTINGENT UPON HOW LONG THE
 EXTREMELY SMALL INNER CORE SURVIVES.  SINCE IT COULD DISINTEGRATE
 AT ANY TIME...AND SINCE IKE WILL BE PASSING NEAR OR OVER A COLD
 EDDY IN THE CENTRAL GULF DURING THE NEXT 24 HOURS...THE HURRICANE
 COULD WEAKEN.  IF...HOWEVER...THE TENACIOUS INNER CORE REMAINS
 INTACT...AND GIVEN THE RECENT PRESSURE FALLS...IKE COULD STRENGTHEN
 SOME AS REFLECTED IN THE OFFICIAL FORECAST.  BEYOND 24 HOURS...THE
 UNDERLYING OCEAN HEAT CONTENT WILL INCREASE ALONG THE FORECAST
 TRACK...AND IKE WILL REMAIN WITHIN A WEAK WIND SHEAR
 ENVIRONMENT...SO MORE ROBUST STRENGTHENING IS FORECAST AT 36-48
 HOURS.  THE NEW OFFICIAL INTENSITY FORECAST IS A LITTLE LOWER THAN
 THE PREVIOUS ONE THROUGH 24 HOURS BUT IS SIMILAR THEREAFTER...AND
 IS ROUGHLY A BLEND OF THE HWRF AND GFDL...BUT HIGHER THAN SHIPS AND
 LGEM.  THE APPARENT WEAKENING BETWEEN 48 AND 72 HOURS IMPLIED BY
 THE OFFICIAL FORECAST SHOWN BELOW ONLY RESULTS FROM IKE GOING
 INLAND...BUT NO WEAKENING TREND IS ACTUALLY ANTICIPATED LEADING UP
 TO FINAL LANDFALL.
 
 THE CENTER OF IKE HAS CONTINUED TO MOVE NORTHWESTWARD OR 315/6...A
 LITTLE TO THE RIGHT OF THE PREVIOUS FORECAST TRACK...BUT VERY
 RECENT SATELLITE IMAGERY AND THE LAST FIX FROM THE NOAA HURRICANE
 HUNTER AIRCRAFT SUGGESTS THE TURN TOWARD THE WEST-NORTHWEST COULD
 BE STARTING.  ALL MODEL GUIDANCE FORECASTS A WEST-NORTHWESTWARD
 MOTION DURING THE NEXT 48 HOURS TO THE SOUTH OF A STRONG RIDGE OVER
 THE SOUTHEASTERN UNITED STATES THAT IS FORECAST TO BUILD WESTWARD. 
 IN A COUPLE OF DAYS...ALL OF THE MODELS FORECAST A WEAKNESS IN THE
 RIDGE TO DEVELOP OVER TEXAS AND EVENTUALLY INDUCE A TURN TO THE
 NORTHWEST AND NORTH...BUT THEY DO NOT AGREE ON WHEN THAT TURN WILL
 OCCUR.  THE HWRF IS ON THE LEFT SIDE OF THE GUIDANCE ENVELOPE AND
 FORECASTS A STRONGER AND LONGER-LASTING RIDGE THAT TAKES IKE INTO
 DEEP SOUTH TEXAS BEFORE TURNING NORTH.  CONVERSELY...THE GFDL IS
 THE RIGHTMOST MODEL WITH A WEAKER RIDGE THAT ALLOWS IKE TO TURN
 INTO THE GALVESTON AREA.  THE OTHER MODELS ARE IN BETWEEN...AS IS
 THE OFFICIAL FORECAST....WHICH IS NOT APPRECIABLY CHANGED FROM THE
 PREVIOUS ADVISORY SINCE THE MODEL CONSENSUS HAS BARELY BUDGED.  
 SINCE THE TIMING OF THE TURN BEFORE LANDFALL IS SO UNCERTAIN AND SO
 KEY IN WHERE THE CORE OF IKE COMES ASHORE...AND SINCE IKE WILL BE
 ROUNDING THE RIDGE AND NOT GOING IN A STRAIGHT LINE BETWEEN 48 AND
 72 HOURS...ONE SHOULD NOT FOCUS ON THE EXACT TRACK.  EVERYONE IN
 THE HURRICANE WATCH AREA HAS ABOUT THE SAME RISK OF HURRICANE
 CONDITIONS.
   
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      11/0300Z 24.9N  86.7W    85 KT
  12HR VT     11/1200Z 25.4N  88.0W    90 KT
  24HR VT     12/0000Z 26.0N  90.0W    95 KT
  36HR VT     12/1200Z 26.7N  92.4W   100 KT
  48HR VT     13/0000Z 27.7N  94.6W   110 KT
  72HR VT     14/0000Z 31.5N  96.5W    55 KT...INLAND
  96HR VT     15/0000Z 36.0N  93.0W    30 KT...INLAND
 120HR VT     16/0000Z...ABSORBED
  
 $$
 FORECASTER KNABB