You may wish to believe it that way, but it was really a combination of an eyewall replacement cycle and cooler waters just offshore that likely caused Dennis to weaken. Last year was somewhat of an abberation for tropical cyclone tornadoes, with so many from all of the storms; the number seen with this one so far (about 5-10) is more of a normal figure.

Winds that may translate down to the surface from upper levels (not downbursts here...but just the wind speed that is found at the lower levels in conjunction with the upper level winds) are generally going to be higher over water than over land due to frictional effects. There is much less friction over water than there is over land, leading to higher wind speeds. Friction can knock quite a bit off of a storm's intensity pretty quickly all by itself; the loss of the warm waters will serve to weaken the storm even further once it makes landfall. The combination of the two factors helped to see the quick change in structure and intensity once inland.

With the storm moving north, almost all of the convection, outflow, and light/moderate tropical rains is going to be found on the north side -- this holds true for just about every such tropical cyclone. The outer feeder bands are nothing out of the ordinary; while the dry slot to its east may not occur with every storm, it certainly is not an uncommon experience, either. Needless to say, Dennis was a pretty formidable storm at landfall, one which the Pensacola area will be cleaning up from for years to come. Category 2, category 3, category 4...it doesn't matter...the damage is still going to be very extensive.