Katrina surge info from a Structural Engineer

[Ixolib]

Well, in my case "a few feet" made a HUGE difference.

Of course. But I doubt you care whether the NHC officially calls it 28 or 31 feet or whatever, since that changes nothing.

You are absolutely right about that!! I often wonder why the NHC is the presumed expert anyway on such things as surge and other storm aftermath. Surely they are experts on forecasting and tracking weather systems, but equally as sure is the fact that experts exist in other fields who could perform a more detailed and pertinent review & analysis of damage and impacts.

[MGC]

What gets me are the folks who have never been here, only seeing the damage in picture or on TV telling me how high the water got. Every day I see logs in trees 20 feet up. The water line on I-10 at the Kiln exit which is a three feet shy of the bottom of the bridge. They sure didn't blow up there.

[dhweather]

What gets me are the folks who have never been here, only seeing the damage in picture or on TV telling me how high the water got. Every day I see logs in trees 20 feet up. The water line on I-10 at the Kiln exit which is a three feet shy of the bottom of the bridge. They sure didn't blow up there.

And if a weak cat 3 did that, then imagine what a cat 5 would do -
a storm surge up to Picayune or so?


I'll never understand how someone can sit in a office far from here,
and tell me how bad it was here. I see it every day as well. I talk to
people who lost everything because of it. I see people still living
in tents because they have nowhere else to go.

Two degreed meteorologists I work with completely disagree with the
Katrina best track. Once Hurricane Hunter I spoke with that was in
Katrina as she made landfall in SELA believes it was a 5 at the SELA
landfall.

Oddly enough all three of these individuals believe that Katrina was
"downgraded" due to political pressures.

[Derek Ortt]

I think I can understand what is happening with the Katrina landfall intensity debate because the same is going on In Miami

Many in Miami and the rest of South Florida are convinced that they survived a category 3 hurricane. However, ALL available data suggests that it was only category 1 conditions, and low to mid cat 1 at that, with isolated cat 2 in Lauderdale, PB, and by the Lake. Most stubbornly refuse to accept that (and I hope they dont come crying after a real cat 3 devastates the area and catches them offguard).

It seems as if something similar has happened. Katrina produced the highest storm surge and storm tide anywhere in the USA, ever, and many areas for the first time saw real upper cat 2 or even cat 3 conditions for the first time. it is natural to believe that what happened was worse than it really was, especially after living through it myself

[Pearl River]

dhweather wrote:

MGC wrote:
What gets me are the folks who have never been here, only seeing the damage in picture or on TV telling me how high the water got. Every day I see logs in trees 20 feet up. The water line on I-10 at the Kiln exit which is a three feet shy of the bottom of the bridge. They sure didn't blow up there.


And if a weak cat 3 did that, then imagine what a cat 5 would do -
a storm surge up to Picayune or so?


I'll never understand how someone can sit in a office far from here,
and tell me how bad it was here. I see it every day as well. I talk to
people who lost everything because of it. I see people still living
in tents because they have nowhere else to go.

Two degreed meteorologists I work with completely disagree with the
Katrina best track. Once Hurricane Hunter I spoke with that was in
Katrina as she made landfall in SELA believes it was a 5 at the SELA
landfall.

Oddly enough all three of these individuals believe that Katrina was
"downgraded" due to political pressures.

dhweather and mgc, thank you so much. I have said this myself on numerous occassions. I guess since I'm the new kid on the block, they feel they can push me around enough to follow their lead and I won't. I regret I have come out angry in response several times, but for someone in another state not even close to here to tell me how bad it was and what I have seen couldn't have happened, I'm sorry but I take offense to it. For someone in another state to say the levee's in New Orleans failed during cat 1 conditions obviously had not seen the state Lake Pontchartrain or the MR-GO was in. The winds did not cause the breaches, it was the water pressure against the levee's, whether the levee's were in poor condition or a barge broke thru one. Also against popular belief, the levee's failed during the hurricane and not the day after.

[dhweather]

Katrina is a very emotional issue for most of us that she impacted, from New Orleans to Mobile.

All I have asked anyone to do is come here and see for themselves
before they say how bad Katrina was. Listen to the stories of people
that rode her out. See the high water marks for yourself.
See the trees down, the antenna towers down, the damage is
mind boggling.

[wxman57]

Katrina is a very emotional issue for most of us that she impacted, from New Orleans to Mobile.

All I have asked anyone to do is come here and see for themselves
before they say how bad Katrina was. Listen to the stories of people
that rode her out. See the high water marks for yourself.
See the trees down, the antenna towers down, the damage is
mind boggling.

I've been there, dhweather - 3 occasions now while rebuilding my mother's home on the MS coast. From what I saw, most of the damage was from storm surge. I saw less wind damage than I would have suspected. For the most part, it looked like Cat 1 and very few Cat 2 winds across southern Mississippi. Less wind damage than I saw in Elena of '85 and Frederic in 1979. But, certainly, the storm surge was something else. I agree with Derek, people just cannot fathom that their lives were nearly destroyed by Cat 1 and Cat 2 winds - but it's true.

It just goes to show that you cannot estimate storm surge by maximum surface winds. You have to consider the whole envelope of high winds. Katrina had a massive area of 75+ mph winds - and that's what produced the large storm surge for the most part. There is no such thing as a "Cat 3 Surge" or a "Cat 5 Surge". Surge height is determined by the expanse of high winds, not the peak wind in a small section of a hurricane.


Here are the links to the pictures I took over the past few months:

On my trips to Mississippi, we went along the coast on Highway 90 to take pictures. The first set of pictures was taken on October 19th along Beach Street in Pascagoula and in Ocean Springs:

http://myweb.cableone.net/nolasue/KatrinaPascagoula

http://myweb.cableone.net/nolasue/KatrinaOceanSprings

By the time I returned to Mississippi after Christmas, Highway 90 between Biloxi and Pass Christian had opened and I took pictures from Biloxi heading west toward Pass Christian. I THINK I have the pictures in the proper folders. Believe me, it was hard to tell where one city stopped and the next one started. Total devastation all along highway 90 for blocks inland.

Looking out at the beach, it's just a sea of debris, still. You can see parts of trees and appliances sticking out of the water along the coast. No swimming along the beach for quite a whiles. Here are the pictures from Biloxi to Pass Christian. There are comments on some of them.

http://myweb.cableone.net/nolasue/KatrinaBiloxi

http://myweb.cableone.net/nolasue/KatrinaGulfport

http://myweb.cableone.net/nolasue/KatrinaLongBeach

http://myweb.cableone.net/nolasue/KatrinaPassChristian

If any of you have additional info about any of the photos, please let me know.

[dhweather]

While I can't say specifics for Port Charlotte from Charley, as I have not
been there, I do see very similar structural and tree damage here
as I saw in photos from there.

I do know that 144MPH was recorded before instrument failure in
Diamondhead. I do know of someone who recorded 160MPH
in Waveland. What were the real wind speeds? Who knows for
certain.

You should stop by Waveland on your next trip over. It's about 8 minutes
South of I-10.

[Derek Ortt]

similar from Port Charlotte from wind? or are you comparing the worst of Charley to the worst of Katrina (Katrina was primarily a water storm, while Charley was solely a wind storm)

[dhweather]

I can't say what the damage is, I haven't been there. I've just seen
photos from Charlotte Harbor and the surrounding areas. The damage
is rather similar, particularly away from the storm surge. Some trees
still stand, some are gone, rooftops vary from light to severe damage,
those types of things.

[dhweather]

Another thing I encourage folks to look at are inland photos (i.e.
non storm-surge) damage from Camille and Andrew. You see
things like 2x4's driven through palm trees. I saw one of a car simply
blown ontop of another car.

If you have cat 5 winds, you know it, simply based on the appearance
of the photographs. The recent Evansville, Indiana tornado damage
looks similar to cat 5 wind damage.

[MSRobi911]

I guess I have to add my two cents in here. One possibility of the reason there was not a lot of evidence of wind damage was that it was all underwater at the time. I experienced the wind and know for a fact that the Jackson County Emergency Operations Center in Pascagoula had a reading of 122 (this number may be a couple of mph's off as I can't remember exactly the number, it was 122 or 125) sustained winds and 136 gust prior to their gauges being blown off the roof, along with part of the roof, as I watched from across the street. This was right as the water started coming in fast and everyone from the EOC had to evacuate the building to the courthouse where we eventually had 5 1/2 feet of water inside.

If you take a ride up through the back roads to Wiggins through the Red Creek Wildlife Reserve and through D'Iberville and on up to Hattiesburg you can see plenty of wind damage with roofs gone and trees down. My aunt works at Red Creek and she said they lost so many trees it will take approximately 3 years to get them all cut down and picked up. My daughter was in Oxford Mississippi in the very north of the state and they experienced strong winds and lost power for three days in her apartment.

As for the water line/debris line.....this is not where the highest water was. I watched and measured where the water came up to in the courthouse and when it went out the water line/debris line was approximately a foot, give or take a few inches, lower than where the water actually was.

Mary

PS Dang it I forgot the main reason I was writing in here, it was to say that one of the deputies has a video from his patrol car of the waves crashing over the I-10 bridge between Gautier and Pascagoula. This bridge is approximately 22 feet above the water and this was not at the highest point that it got.

[Aslkahuna]

Those are Cat 3 winds and not much above what NHC had for the second landfall (120mph). That's the problem as we see more reports of winds coming in. Overland, wind gusts of 144-160 mph can occur with Cat 2 to low end Cat 3 sustained winds-in fact, a gust to 160mph overwater would be associated with sustained winds of 130mph which is top end Cat 3 so everything still supports Cat 3 winds and will until we can get a verified report of either a higher sustained wind or a gust that would support a sustained wind of 131mph or higher. As I mentioned some time ago, The Gulf Coast was hit by a storm that was more typical of a typhoon in size and wind stucture than a typical ATL hurricane (ironically, while Katrina is an old EPAC name with a nasty history, Rita is an old typhoon name with an even nastier history).

Steve

[HurricaneBill]

(ironically, while Katrina is an old EPAC name with a nasty history, Rita is an old typhoon name with an even nastier history).

Steve

And we replaced Isidore with Ike!