From the Mobile,AL Forecast Discussion:

THERE ARE A NUMBER OF "WHAT-IF`S"
INCLUDING THE POSITION OF HERETOFORE UNPREDICTED FEATURES IN THE
WESTERLIES THAT COULD STEER THE STORM DIFFERENTLY THAN WHAT WAS
THOUGHT OR CALCULATED...OR WHAT WOULD HAPPEN IF THE DRY AIR TO THE
NORTHWEST WERE INGESTED INTO IKE.

IT WILL BE SEVERAL DAYS BEFORE
ANYONE CAN SAY WITH MUCH MORE CONFIDENCE WHERE THIS TRACK WILL BE.
ONE MUST RECALL THAT THE ERROR CIRCLES (CONE OF UNCERTAINTY)
REPRESENTS A 2/3 CONFIDENCE WHICH IS A RUNNING AVERAGE OVER THE LAST
FIVE YEARS. THAT UNCERTAINTY IS THE REASON WHY IT IS IMPORTANT THAT
ALL INTERESTS CONSTANTLY STAY POSTED ON WHAT IS HAPPENING WITH THIS
HURRICANE. 77/BD

http://www.srh.noaa.gov/printable.php?pil=AFD&sid=MOB&date=2008-09-07%2009:31:17