Katrina H-Wind Analysis, marginal 3 at landfall

[Scorpion]

What about the 233 kt wind at about 1800 ft recorded? That would yield 186 kts at surface. I wonder if the winds were stronger than 175.

That was ruled as bogus.

Even if it was not bogus, the 233 kt was a gust and not a sustained wind, so it is entirely possible.

No, I believe the 233 was sustained.

[Derek Ortt]

it normally is 90%, but only if there is high ocean heat content near the land, like Miami, or the Caribbean. At Cuba, Charley was actually 105%

I do not believe NWS in the center of New Orleans recorded cat 3 sustained from Betsy as the highest readings I have seen were 105 m.p.h. gusts, but cat 3 sustained at Grand Isle

[MGC]

Impossible in a storm of Katrina's size. 186KTS is like 214mph...no way.....MGC

[Derek Ortt]

no,

the 233 was bogus and a gust

[senorpepr]

What about the 233 kt wind at about 1800 ft recorded? That would yield 186 kts at surface. I wonder if the winds were stronger than 175.

That was ruled as bogus.

Even if it was not bogus, the 233 kt was a gust and not a sustained wind, so it is entirely possible.

No, I believe the 233 was sustained.

No... it was a gust. Regardless, it was still bogus.

[timNms]

When will the "powers that be" present their final analysis of Katrina?

[Brent]

When will the "powers that be" present their final analysis of Katrina?

The NHC report will be out sometime after the season is over...

[timNms]

Another question for the experts. After Andrew, the building codes were changed for South Florida, correct? Is it possible that a majority of the damage caused by Andrew was due to less than "up to standard" building techniques? (homes lacking hurricane straps, etc.) Not saying Andrew was less than a cat 5, just wondering if some of the damage could have been prevented had the building codes back then been what they are today.

[Scorpion]

Thats odd that it was bogus, it would have coincided with the gusts to 215 mph that 175 mph hurricanes should have.

[Derek Ortt]

the codes were still the best in the entire USA. I do not know of any other region that required roofs and shingles to withstand SUSTAINED 65 m.p.h. winds, since we see 50 m.p.h. sustained with gusts to 90 taking roofs and shingles off when canes hit other places. After Andrew, we then adopted the Cayman Code, which basically requires everything to be built like a fortress, where roofs and shingles are now required to withstand SUSTAINED winds of 110 m.p.h.

[Derek Ortt]

my place is about a mile SSE of the old NHC, meaning we were in the borderline 3/4 conditions, and damage was relatively minor from what I have been told in South Miami. It was only the cat 5 region that ahd damage.

The codes were fine then and as Ivan showed, Andrew again likely will have similar results

[senorpepr]

Thats odd that it was bogus, it would have coincided with the gusts to 215 mph that 175 mph hurricanes should have.

A) Katrina was most likely never 175 mph, per NHC.
B) That wind report was well aloft.
C) 80 feet above and below that report winds were much lower. Pretty hard to get a gust in one very small part of the atmosphere.

[Derek Ortt]

NOAA aircraft had 166KT over the loop current briefly, probably did top out at 150KT, but the next pass showed that the winds had already started to decrease and that an outer wind max had started to form

[HurricaneBill]

Do you think it would be better to have categories within categories?

In other words, different types of Category 1s, 2s, 3s, 4s, and 5s?

The sub-categories would be based on the storm surge, wind field, speed, etc.

[wxmann_91]

A few things I want to note: (BTW Derek I respect all your opinions and analyses, I know the dropsondes and doppler velocities indicate otherwise)

a) According to the HRD analysis, the peak intensity was not a Cat 5, instead a Cat 4. How do you explain that?

b) It clearly states on the bottom that it is an "experimental research product". I don't really like to take experimental research products as gospel. EDIT: Oops that was on old graphics, but it does say on the top of the page.

c) Three hours after landfall in max winds were still 100 mph. ???

All these things indicate that the HRD analysis could be flawed. BTW I am not including any of the other data that could indicate a stronger or weaker storm.

DISCLAIMER (yes it is needed for this thread): I am not attacking anybody, just their ideas.

[Derek Ortt]

there are two difference numbers given on the H-Wind, analyzed wind and observed wind. For Dennis, their analysis yielded 101KT, but the observed was 106KT. For Katrina, the analyzed matches and observed. The map is the analysis

[TSmith274]

When the NHC studies hurricanes to confirm what category it was, do they only study atmospheric data, radar, and the like? Or, do they also put "boots on the ground" in the hardest hit areas to study damage? If so, this may trump any overanalyzed data. I say this because, in Plaquemines Parish, damage exceeds any imaginable level. It is truly unbelievable. "Unbelievable" is a very over-used word. But it is very fitting down in Plaquemines Parish, especially in the Port Sulphur/Buras area.

We, as human beings, like to think that we have a full understanding of most things. But, even in our advanced civilization, with all sorts of technology to study huricanes... sometimes mother nature puts us in our place. IMO, Katrina was a good example of this.

[Derek Ortt]

no, only atmospheric data is analyzed in compiling a BT

[Derek Ortt]

I dont think we need subcategories, we just need a media that actually will report the facts to better educate the public as all of the info is contained in the public advisory. The media just never relays it properly

[Matt-hurricanewatcher]

Emily also top out 153 knots at 03z.