Well actually, more like an intrusion of dry air that got sucked in from the land (always a problem when these huge (diameter wise) storms get anywhere near land. Its like a vacuum that sucks in a chord and wraps around the spindle brushes choking the mechanism.
For you football fans...I'd compare this to Terrell Owens running head first into Warren Sapp. BAM!
It looks as though Rita is emerging off of the Loop Current Eddies and into cooler water(but still more than warm enough to sustain CAT 3-4 Status) as demonstrated by the following image....