Katrina H-Wind Analysis, marginal 3 at landfall

[Scorpion]

I agree. I am thinking Camille was more around 175 mph or so. Books have Camille as 200 mph. Ridiculous.

[f5]

not a surprise at all

the data is starting to be very conclusive that Katrina did weaken to a category 3 hurricane just before making landfall

since you live in miami back in 1992 did you think Andrew was a CAT 5 beacuse he hit 30 miles to your south when they had him as a CAT 4?were you being bias since he struck in your backyard the folks in mississippi feel the same way and i understand that by looking at the Hiroshama type damage

[Derek Ortt]

I was in Niagara Falls for Andrew, so all I can go on is the objective data

That said, at one point, I did slightly overestimate the winds from the roof of the MSC building at RSMAS during Katrina. I had thought we had hurricane force winds during the passage of the west eye wall, but the reading was only 65 m.p.h. sustained with hurricane gusts. I was on the roof again when we truly had hurricane conditions (very marginal cat 1), and let me tell you that those looked so similar to the so called major hurricane footage that you see on TV./ Conditions at RSMAS were about as bad as they were in Beaumont for Rita (we had higher sustained winds, but the gusts here were about 10 m.p.h. lower)

[vbhoutex]

I agree. I am thinking Camille was more around 175 mph or so. Books have Camille as 200 mph. Ridiculous.

What makes that ridiculous? I'm not saying it happened, but unless you can prove it didn't happen I wouldn't make such bold statements. There are published reports of winds gusting to 220 mph at Keesler AFB in Biloxi(by intrumentation which was of course destroyed). Unproven? Yes, ridiculous? I don't think so. It is definitely possible. Show me more proof before making bold statements like that.

Now let's take this back to Katrina.

[Scorpion]

If the original intent of this thread was to say that Katrina was 100 kts at MS landfall then I would believe it. However, there is no way Katrina was 100 kts at Louisiana. Recon supported Cat 4. Pressure was 918. I didnt see any decaying eye structure. In Ivan or Rita, the pressure jumped way up, about 35 mb from peak for Rita and 25 mb for Ivan. In Katrina, there was an increase of 16 mb or so. And Katrina's pressure only rose slowly as she came in. Unlike the other storms. This leads me to believe Katrina was NOT weakening rapidly at landfall. A 50 kt decrease in winds before landfall is quite doubtful.

[timNms]

I agree. I am thinking Camille was more around 175 mph or so. Books have Camille as 200 mph. Ridiculous.

What makes that ridiculous? I'm not saying it happened, but unless you can prove it didn't happen I wouldn't make such bold statements. There are published reports of winds gusting to 220 mph at Keesler AFB in Biloxi(by intrumentation which was of course destroyed). Unproven? Yes, ridiculous? I don't think so. It is definitely possible. Show me more proof before making bold statements like that.

Now let's take this back to Katrina.

It was a bit windy here during Camille. Katrina's low pressure set the record at Jackson...beating the former lowest pressure set by Camille in aug. '69

[Charles-KD5ZSM]

I agree. I am thinking Camille was more around 175 mph or so. Books have Camille as 200 mph. Ridiculous.

Camille was sustained 190mph. Gusts broke the anemometers at 220 mph. The books aren't wrong.

[MGC]

I have to agree with Dereck on this one. No way Camille had 190mph sustained winds at landfall. It is an established fact that hurricanes were over estimated back then. I still think Camille was a Cat-5 because of her small eye. Had Katrina had a small eye she would have been a Cat-5 too with a 918mb pressure. Same with Rita. Pressure gradient is the rule of law with wind speeds. Huge storms like Katrina, Rita and Ivan have much lower pressure gradients than small storms like Andrew, Charley and Camille......MGC

[timNms]

Derek, you really should make a trip over to Waveland, Bay St. Louis and Pass Christian to see the destruction for yourself. Then you would get a true picture of what a monster Katrina really was.

A retired meteorologist I know was there, in the storm, struggling to save his life and the lives of his wife, mother in law, and son. He swears the winds were at least 145 mph and the surge was 40 feet.

Oddly, i've read on here that the surge came in from the south? Actually, in Waveland, if one follows the debris (if you can even call it that) one finds that the surge was traveling SE to NW. A few dishes from their home was found to the NW of their gulf facing home.

[Aslkahuna]

Not so odd, since the winds would have been from SE so anything on the water surface would have moved NW. The winds proper would not have shifted south until the ete passed by. I'm not sure where this 918mb pressure at landfall is coming from because I thought it was 923mb on the first landfall and 927mb on the second.

Steve

[djtil]

He swears the winds were at least 145 mph and the surge was 40 feet

does anyone really have the life experience necessary to personally judge between 115mph w/gusts or 145mph w/gusts? i really doubt this guy is a well calibrated wind machine at those extremes, met or not.

[timNms]

Not so odd, since the winds would have been from SE so anything on the water surface would have moved NW. The winds proper would not have shifted south until the ete passed by. I'm not sure where this 918mb pressure at landfall is coming from because I thought it was 923mb on the first landfall and 927mb on the second.

Steve

I knew that, Steve. Was just wondering if that was the angle some on the board were talking about that cause such a massive surge. My fingers didn't type what my brain told them too

[timNms]

He swears the winds were at least 145 mph and the surge was 40 feet

does anyone really have the life experience necessary to personally judge between 115mph w/gusts or 145mph w/gusts? i really doubt this guy is a well calibrated wind machine at those extremes, met or not.

Actually, the guy knew John Hope, but not sure if it was as a co-worker or from some other weather related outlet. I'll try to find out about his "qualifications" the next time I get a chance to sit down and talk to him. Currently, he and his family are living in South Carolina with relatives. I would tend to take his word for it over someone who was not there nor have been there to see what it's like after the storm.

[Derek Ortt]

even I over estimated the winds in Miami, saying we had 75 m.p.h. when we had 65. I was outside when we had real hurricane conditions, and I either said earlier in this thread or in another that what I saw from 75 m.p.h. winds with gusts to 90 m.p.h. was as bad as Anderson Cooper went through in Beaumont (sustained was higher, but gusts were lower)

most have not went through true hurricane conditions, or at least before Katrina; thus, it is very hard to make a comparison

[Derek Ortt]

I NEVER would have thought it was possible, until my flight into Rita, but I am believing that MAYBE Camielle was also a 3. In Rita, we had a 911mb pressure, yet the dropsondes and SFMR were only indicating a 105-110KT hurricane, despite 133KT 700mb winds. A large wind field with a small eye, as Rita and Camielle had often is condusive to lower wind speeds as the pressure gradient is spread out over a larger area, while a large storm with an Isabel-like eye would produce a stronger wind speed since you had the flat low-pressure over a large area in the eye, which quickly increases to the environmental pressure

What would be great to compare, if the data is still available, is the vertical velocities in the eye wall of Katrina and Camielle, to determine the momentum transport from 700mb to the surface (and compare the 700mb levels with other storms to determine if 90% even applies since the 700mb height is likely significantly lower due to the very low pressure)

[MGC]

Dereck, you are really stiring the pot here suggesting Camille was a Cat-3.......MGC

[Scorpion]

Well, it doesnt seem far fetched. Camille had hurricane force winds over Pensacola somebody said. Thats a huge windfield, and her eye was quite small. Also was within 10 mb of Katrina at landfall.

[HurricaneBill]

Dereck, you are really stiring the pot here suggesting Camille was a Cat-3.......MGC

It seems like EVERY major hurricane to hit the Gulf coast was a low-end 3 to Derek.

Watch out, Carla and Audrey. You're next.

[Scorpion]

Dereck, you are really stiring the pot here suggesting Camille was a Cat-3.......MGC

It seems like EVERY major hurricane to hit the Gulf coast was a low-end 3 to Derek.

Watch out, Carla and Audrey. You're next.

They likely were Cat 3's. Carla was enormous and had a pressure similar to Rita. Audrey was 945 mb, and had a rather large eye.

[Derek Ortt]

Carla probably was legitimatly a 4. I would have to look at the flight level data, with the vertical velocities

again, had my Rita experience not have happened, I would have thought the idea was downright laughable. What is needed is numericla modeling studies to determine WHEN and WHY some storms like Rita can be 911mb cat 3's, after being 897mb cat 5's