No. In fact, just because you said that, I am going to make it my mission to spread the confirmed fact that Katrina made landfall as a Cat-5.
Cuz she did.
Prove it.
Monday, August 29:
6:10 AM CDT: Katrina, a Category 4 hurricane with 145 mph winds, makes initial landfall near Buras, La.
Monday, August 29
7AM CDT – KATRINA MAKES LANDFALL AS A CATEGORY 4 HURRICANE [CNN]
Hurricane Katrina devastated portions of the central Gulf of Mexico U.S. coast from Southeast Louisiana to Alabama at the end of August and will most likely go down as one of the worst natural disasters in the history of this country. Katrina's deadly track began as she moved across South Florida. Katrina then strengthened into a Category 5 Hurricane while moving northward toward the Central Gulf Coast. Although Katrina weakend before landfall, the Category 4 hurricane's fierce winds and near-record storm surge were still able to cause widespread destruction and loss of life.
National Weather service
http://www.srh.noaa.gov/hgx/
Actually it did make landfall as a Cat-4. Joe Kosek, accuweather.com Senior Meterologist told Shep tonight on the Fox Report, because Shep asked Joe if there was a possibility Rita could weaken before it made landfall, and Joe explained to him that's what happend to Katrina, even though it still raised havoc on the Gulf Coast.
As many hurricane experts would tell you, it's not the hurricane that causes the most damage, it's the storm surge.