That is not correct. Sustained winds were very likely below Cat 1 (i.e. NOLA proper never experienced sustained hurricane-force winds).High-rises probably experienced Cat 1 sustained winds for a very short time on the upper levels.

NOLA likely experienced some hurricane force gusts, and probably not very many, as they were just grazed by the weak western side of the hurricane. Recall that news crews flew in and were broadcasting from NOLA on Monday afternoon, with not even enough of a breeze to ruffle the hair of the news anchors, during which time the MS Gulf Coast was still experiencing occasional hf gusts, and surge had not yet even receded from inland areas.

Areas that were actually on the GOM, like St Bernard and Lake Catherine, likely experienced Cat 1 winds, but that is rather a moot point, as the damage all came from surge (these areas were completely inundated by high rising water...the waves were likely not very high, because no high winds existed to create high waves). Surge probably did rise very rapidly in both those areas.

I have spent part of my January finding and reviewing videos of Katrina. What a fun job that was. I think I've gone through several hundred at least by now. Seems like everyone who had a car and a video camera made their own badly-shot video and decided to set the footage to their favorite music (a fairly random and usually not appropriate group of selections).

I did find some good ones though, that had clear indications of the extent of wind and wind damage, usually trees, also the height of the waves on the surge.

All I can say is that seeing is believing.

It appears that Gulfport had the highest sustained winds and these look to be around 90mph, with some gusts over 100mph, and there may have been a few gusts as high as 110 or 120mph, but I did not see a video with any gusts that high.

Biloxi's sustained winds looked to be around 65mph, and Pascagoula, around 40-50mph (with higher gusts).

It appears that Katrina was very gusty, especially after the peak winds had passed on the coast, and also when the storm went through inland MS.

Wind damage along the MS Gulf Coast, in areas that were inland of the most significant surge, appear to be in buildings that would be susceptible to wind damage (gas station canopies, buildings with a wall of large windows such as an auto dealership) from repeated weaker gusts, rather than one strong gust. There is at least one good example of this on a website that shows successive gusts weakening a building with large windows, where flying debris had broken the windows, and the remaining structure behaved more or less like a tent canopy held down with stakes. There is another video that shows the first floor of a hotel being slowly demolished by gentle waves of surge, which actually remove the metal framing of the doors from the building, among other things, with not a single bit of damage due to wind (most structures are not designed to withstand extremely large side loads that come from moving water, which can exert a tremendous psi).

Regarding HurricaneJosh's comment, "it is just amazing that winds weren't higher, given the landfalling presure of 920 mb," that is addressed in the post TC report. Special note is made of it. In summary the wind gradient weakened and spread out prior to landfall.

Have also spent a lot of time looking at the surge along the MS coast. I'll refer to it as surge although it is more accurately called storm tide (storm tide includes the high tide, which is between 1 and 2 feet all along that section of coast, along with the surge). It was Cat 3 all the way out to just NE of the Pascagoula city limits, which is around 85-90 miles to the east of the storm's center at landfall. Cat 4 surge was experienced along a very shallow area of shoreline on either side of St Louis Bay. There appears to be no Cat 5 level surge. I am referencing the surge heights from the MS Hurricane Evacuation Study (HES) maps, which used many SLOSH runs to determine worst-case surge heights from the MEOWs.

Have been sending a flurry of emails w/Jeff Masters recently regarding the surge. He'll shortly be posting a blog entry that will explain the dynamics of the surge.