Katrina H-Wind Analysis, marginal 3 at landfall

[frederic79]

I agree. The angle of landfall is paramount. Look at Georges at Cat 2 with a 14 foot storm surge in 1998. But surge aside, when has a Cat 3 storm ever caused a 25-30 ft. storm surge, at any angle? A good example is Lili in 2002. Lili reached 145 mph/Cat 4 status in the central Gulf before weakening to a 105mph/Cat 2 at landfall in LA. There was no huge storm surge there. The surge in Katrina reflects it 923 mb pressure, not a dramatically weakened hurricane. Even Ivan was said to have 135 mph winds at landfall and Ivan's surge wasn't like Katrina's. The debate will continue but I would really like to know how a 125 mph storm could totally obliterate 80+ miles of coastline in Mississippi regardless of it's windfield size.

[Droop12]

For the people talking about lightning and thnder in hurricanes...Dont you think it could be transformers exploding? I been in 2 canes' and during both for about an hour after the hurricane force winds started there were loud claps of thunder that turned out to be just all the transformers exploding in the city. They also produce blinding light if you see them up close.

[oneness]

For the people talking about lightning and thnder in hurricanes...Dont you think it could be transformers exploding? I been in 2 canes' and during both for about an hour after the hurricane force winds started there were loud claps of thunder that turned out to be just all the transformers exploding in the city. They also produce blinding light if you see them up close.

No, the first (cat 4) occurred in a remote and undeveloped desert coastal area, and the other (cat 2) occurred looking out over open water, plus it was witnessed by over 150 thousand people and recorded on Television cameras and played on the news.

I've seen transformer flashes many times and this was not transformers. These were the most powerful lightning discharges I've ever seen, and by far the most impressive thunder I've ever heard. The cat 4 was an Indian Ocean basin cyclone, and the cat 2 was a Coral Sea cyclone. I've been in several other cyclones, and normally there is no lightning or thunder in them. Every storm is different.

[senorpepr]

As I've posted in another thread...

A 918 mb storm will do 918 mb damage.

However you debate it, I believe that the NHC will only move Katrina's winds at landfall up or down 5 mph. The bottom line is that Kat was a Cat 4 at landfall in LA and a strong Cat 3 at landfall in MS.

Huh?? A 918 mb storm will do 918 mb damage?

So a 1004 mb storm will have the same winds regardless of structure or surrounding pressures? Doesn't make sense, because we all know that at different mb's storms have been lower and weaker than others and so on.

???

I meant that a hurricane with a 918 mb pressure, regardless of its winds (trust me, they won't be of Cat 2 strength or lower), will do what you would expect a 918 mb hurricane (marginal Cat 5) would do, even if it is not a Cat 5. Likewise, a hurricane with 980 mb pressure you should expect strong Cat 1 damage regardless of wind speeds.

This is meant as a general rule of thumb. If a hurricane stalls and causes flash flooding the intensity does not matter. But otherwise it works well.

A 918 mb hurricane with 130 mph winds will do exactly 130 mph in damage. Pressure doesn't cause trees to uproot, shingles to fly off, debris to strike windows, or the vast majority of the storm surge. Wind and windfields are all that matter.

I don't think this is accurate. A 918mb storm will do damage like other 918mb storms, not more like storms of similar windspeeds. This does assume a "flat world," as in we are not passing directly over any city areas.

A 918mb storm with 130mph winds will have multiple wind maxima and a large eye, so you get Cat 3 winds over a radius of 80miles versus a 170mph storm with winds over only 15 miles. Of course, if those winds are centered directly over Tampa, the smaller, faster storm will do more damage, but over a range of coastline, both will do the same amount of damage.

The larger storm will likely push a larger surge too, although too many factors such as speed and angle and coastline topography affect this.

No... not all storms of equal pressure produce equal damage. It is the wind speed. A small 918mb storm will produce MUCH more damage than a large 918mb storm because the pressure graident is much tighter therefore the winds are much stronger.

[Stormcenter]

All I have to say to this post is OH PLEASE give me a BREAK!
The pressure speaks for itself and forget everything concerning measurments.

I've "personally" seen the damage in Mandeville,LA, Oceans Springs,MS,Plaquemines parish, Slidell, LA. and other places where Katrina caused her damage. I also saw what Andrew and Hugo did personally and Katrina wins hands down for destruction and isn't this how we should ultimately measure hurricanes anyway?. She was at least a Cat.4 so why do you WASTE your time arguing the obvious? The damage was not ALL caused by the storm surge or weak levees. Her winds did a tremendous amount of damage. I find that "some" of people arguing this are the ones who were not in her destructive path. It is like some kind of envy they have that Katrina did not affect them? I live in Houston and will NOT argue what category she was to anyone who was in her path. It is just so damn irrelevent now. Can we please put it to rest once and for all?

[Derek Ortt]

<i>All I have to say to this post is OH PLEASE give me a BREAK!
The pressure speaks for itself and forget everything concerning measurments.

I've "personally" seen the damage in Mandeville,LA, Oceans Springs,MS,Plaquemines parish, Slidell, LA. and other places where Katrina caused. I also saw what Andrew and Hugo did personally and Katrina wins hands down for destruction. She was at least a Cat.4 so why do you WASTE your time arguing the obvious? The damage was not ALL caused by the storm surge or weak levees. Her winds did a tremendous amount of damage. I find that the people arguing this are the ones who were not in her destructive path. It is like some kind of envy you have that Katrina did not affect you? I live in Houston and will NOT argue what category she was to anyone it her path. It so damn irrelevent now.
Can we please put it to rest?</i>

my response to your dribble that passed as a post would be the same.

Lewts try and debate the facts here, not use arguments that would have been appropriate in midieval times. The throwing out of scientific data because you do not like it is great one esque

[jasons2k]

All I have to say to this post is OH PLEASE give me a BREAK!
The pressure speaks for itself and forget everything concerning measurments.

I've "personally" seen the damage in Mandeville,LA, Oceans Springs,MS,Plaquemines parish, Slidell, LA. and other places where Katrina caused. I also saw what Andrew and Hugo did personally and Katrina wins hands down for destruction. She was at least a Cat.4 so why do you WASTE your time arguing the obvious? The damage was not ALL caused by the storm surge or weak levees. Her winds did a tremendous amount of damage. I find that the people arguing this are the ones who were not in her destructive path. It is like some kind of envy you have that Katrina did not affect you? I live in Houston and will NOT argue what category she was to anyone it her path. It so damn irrelevent now.
Can we please put it to rest?

This is a good, healthy debate and it's VERY relevant when we are trying to benchmark storm intensity in the future. In fact, it's critical. How many people stayed in MS because they thought since they survived Camille, they could survive anything?

And FWIW you'd have a hard time convincing those from Homestead, FL that Katrina's WIND damage was worse. If you were indeed there, how can you say that? I saw the damage in Homestead first hand and it was more akin to an F4 Tornado. I have yet to see wind damage from Katrina that compares. The surge damage is another matter completely but that has to do more with storm size and the coastal geography and comparing surges from a S. FL storm to a Gulf storm is not 'apples to apples'.

[mtm4319]

Whether or not the maximum sustained surface winds were over 130mph, storms like Katrina need to be considered a Category 4 (if not Category 5). If that means we have to remanipulate the Saffir-Simpson scale to reflect that, I think it needs to happen.

[f5]

Did this come close to the December Tsunumi. It sure sounds like it gave that a run for its money. Katrina was one bad hurricane. She was a very big storm which helped formed a storm surge bigger then any hurricane ever. Rita the youger sister did some damage. But Katrina to non-western LA/Eastern Texas people will be the one remembered for this year.

If Rita would of hit the Houston/Galveston area it would of been the storm of the century if would be Catastrophic ten times over .The world economy would collapse beacuse of the oil we have.

[Stratosphere747]

Did this come close to the December Tsunumi. It sure sounds like it gave that a run for its money. Katrina was one bad hurricane. She was a very big storm which helped formed a storm surge bigger then any hurricane ever. Rita the youger sister did some damage. But Katrina to non-western LA/Eastern Texas people will be the one remembered for this year.

If Rita would of hit the Houston/Galveston area it would of been the storm of the century if would be Catastrophic ten times over .The world economy would collapse beacuse of the oil we have.

Really?

Then why do we have to import so much?

[Genequte]

I live in Gulfport, MS; been here all my life. My husband and I swam out of our house at 0930 and rode out the majority of the storm in a neighbor's boat. I saw pine trees bend over with the wind close enough that if I reached up far enough I could have touched the tops. I was hit with debris at was going at least 50MPH. We were covered from head to toe with bruises and abrasions. Katrina was a combination of a large mass of energy with high winds and lots of water. Cat 3, Cat 4 or Cat 5, it doesn't matter. It was a disaster unlike anything seen before and hopefully is not a precursor for events in the future. I don't care what the pressure was at landfall, don't care if gusts were 100 or 200 MPH. I do care that my home is gone and precious momentoes are wet and covered in sluge. I've enjoyed reading this board for several months, but don't really post much. All I am saying is that instead of debating how hard did a storm hit, let's figure out a way to better prepare people. Thank you

[f5]

Did this come close to the December Tsunumi. It sure sounds like it gave that a run for its money. Katrina was one bad hurricane. She was a very big storm which helped formed a storm surge bigger then any hurricane ever. Rita the youger sister did some damage. But Katrina to non-western LA/Eastern Texas people will be the one remembered for this year.

If Rita would of hit the Houston/Galveston area it would of been the storm of the century if would be Catastrophic ten times over .The world economy would collapse beacuse of the oil we have.

Really?

Then why do we have to import so much?

beacuse in this day and age every drop of oil counts thanks in part to china and india

[jasons2k]

Here is Cat. 5 WIND damage, circa 1992:











Grrrrrrrr. trying to fix thumbs. The code is correct but for some strange reason it won't embed the URL with the image. You may have to cut & paste the URL into your browser to see fullsize, sorry, I'm at a loss on how to fix it since the code is right. Strange..........

[Stormcenter]

<i>All I have to say to this post is OH PLEASE give me a BREAK!
The pressure speaks for itself and forget everything concerning measurments.

I've "personally" seen the damage in Mandeville,LA, Oceans Springs,MS,Plaquemines parish, Slidell, LA. and other places where Katrina caused. I also saw what Andrew and Hugo did personally and Katrina wins hands down for destruction. She was at least a Cat.4 so why do you WASTE your time arguing the obvious? The damage was not ALL caused by the storm surge or weak levees. Her winds did a tremendous amount of damage. I find that the people arguing this are the ones who were not in her destructive path. It is like some kind of envy you have that Katrina did not affect you? I live in Houston and will NOT argue what category she was to anyone it her path. It so damn irrelevent now.
Can we please put it to rest?</i>

my response to your dribble that passed as a post would be the same.

Lewts try and debate the facts here, not use arguments that would have been appropriate in midieval times. The throwing out of scientific data because you do not like it is great one esque

As I said before it is so irrelevant now that it's not even worth replying to your posts. It's like arguing whether a person who was shot 5 times was killed by the first or last bullet. The BOTTOM LINE is they are STILL dead. Whether or not she was a Cat.3,4 or 5 makes NO difference now. She will still be one the most deadly and costliest natural disasters the U.S. has EVER experienced.

[Stormcenter]

Here is Cat. 5 WIND damage, circa 1992:











Grrrrrrrr. trying to fix thumbs.

Actually most of that damage was done by numerous strong tornadoes spawned by Andrew and his winds. There were many homes in Homestead that were still standing after the storm with moderate damage.

[jasons2k]

Actually most of that damage was done by numerous strong tornadoes spawned by Andrew and his winds. There were many homes in Homestead that were still standing after the storm with moderate damage.

Most tornadoes in a hurricane are very brief and small in stature. Typically, hurricanes don't produce mile-wide tornadoes as seen in the Plains. Some of the damage was created by tornadoes, but not for blocks and blocks both wide and deep.

[Derek Ortt]

there were not tornadoes in the eye wall

As for saying its not important how strong it was, storm center, I am so glad you are not in emergency management. We must know precisely how strong Katrina was, so that we are better prepared the next time a Katrina like storm comes, be it a 3, 4, or 5

[jujubean]

Here is Cat. 5 WIND damage, circa 1992:











Grrrrrrrr. trying to fix thumbs.

Actually most of that damage was done by numerous strong tornadoes spawned by Andrew and his winds. There were many homes in Homestead that were still standing after the storm with moderate damage.

It seems as if this little debate has turned into my storm was stronger than yours stuff .I am no pro met but have been thru enough storms to know each one has there own personality so to speak....I have to say even as a cat 1, Katrina did quite a bit of damage so I can imagine what it was like for those on the gulf coast as cat 3 or whatever it is or will be categorized that being said andrew was devastating in its own right because it was a different type of storm .damage was caused by winds and tornadoes alike and the damage was in a more concentrated area but not one structure left unscathed. especially in perrine , cutler ridge ,goulds, naranja ,homestead and florida city. so please let's not downplay any storms because they always afffect someone's life.

[jasons2k]

[quote="jujubean]
It seems as if this little debate has turned into my storm was stronger than yours stuff [/quote]

That's not really the point. When people claim Storm A had Cat. 4/5 wind damage, a comparison must be made to a documented Cat. 5 such as Andrew or a Cat. 4 such as Charley. That's the basis for the comparison. It's not a contest per se, as Derek has exhaustively pointed out, it's essential so that we can make adequate plans in the future.

[Stormcenter]

I live in Gulfport, MS; been here all my life. My husband and I swam out of our house at 0930 and rode out the majority of the storm in a neighbor's boat. I saw pine trees bend over with the wind close enough that if I reached up far enough I could have touched the tops. I was hit with debris at was going at least 50MPH. We were covered from head to toe with bruises and abrasions. Katrina was a combination of a large mass of energy with high winds and lots of water. Cat 3, Cat 4 or Cat 5, it doesn't matter. It was a disaster unlike anything seen before and hopefully is not a precursor for events in the future. I don't care what the pressure was at landfall, don't care if gusts were 100 or 200 MPH. I do care that my home is gone and precious momentoes are wet and covered in sluge. I've enjoyed reading this board for several months, but don't really post much. All I am saying is that instead of debating how hard did a storm hit, let's figure out a way to better prepare people. Thank you

The BEST post of the day!!!!!!!!!!!!