From what I read at the 5 am discussion from the NWS there appears to be 2 different senarios:
THERE SEEM TO BE TWO POSSIBILITIES FOR THE INTENSITY BEFORE
LANDFALL. THE FIRST IS THAT A NEW CONVECTIVE BURST DEVELOPS DURING
THE UPCOMING DIURNAL MAXIMUM...AND ARLENE MAKES ANOTHER ATTEMPT TO
BECOME A HURRICANE. THE INTENSITY FORECAST WILL FOLLOW THIS
POSSIBILITY. HOWEVER...THE SECOND POSSIBILITY IS THAT THE ABUNDANT
DRY AIR SEEN IN WATER VAPOR IMAGERY NEAR ARLENE HAS BEEN ENTRAINED
INTO THE STORM AND WILL SUPPRESS CONVECTION DURING THE REMAINING
TIME BEFORE LANDFALL. IF THAT HAPPENS...ARLENE MAY WELL WEAKEN
BEFORE LANDFALL. IT WILL LIKELY TAKE ONE MORE FORECAST CYCLE
BEFORE IT BECOMES CLEAR WHICH POSSIBILITY IS OCCURRING.

THERE IS A DISTINCT POSSIBILITY THAT ARLENE WILL NOT BECOME A
HURRICANE. HOWEVER...THE HURRICANE WARNING FOR THE NORTHERN GULF
COAST WILL REMAIN IN EFFECT UNTIL IT BECOMES CLEAR THAT THIS WILL
NOT HAPPEN.

I guess we just wait and see.

MaryAnn