Extreme weather does have something to do with climate change
John, the question is not how many Cat-3 hurricanes have hit the continental US (CONUS) since Katrina but how many Cat-3 hurricanes there have been regardless of where they occur. Whether they hit the CONUS is just a matter of random chance. For instance the 2010 Atlantic hurricane season was the third most active in the records and had 12 hurricanes of which 5 were Cat-3 or above. None of them hit the CONUS.
Global warming increases the level of energy in the Earth's climate. How could you think that wouldn't manifest itself in changes in weather?