This arguement has gone on for 4 months to the day almost so

[Derek Ortt]

should have rephrased what I said, surge only becomes meaningless if you actually get sustained cat 4 or 5 winds (as the gusts then start approaching 200 m.p.h.)

Holmes in Cayman were designed to withstand major hurricane conditions, and Ivan flattened them, partially due to the fact that the eye wall sat over the coast for a long time Similar happened in south dade (BEFORE I came here) during Andrew


my point is that while the surge brings destruction straight from hell, lets not make the pre Andrew mistake in thinking that the winds do not cause that much damage

[Frank P]

should have rephrased what I said, surge only becomes meaningless if you actually get sustained cat 4 or 5 winds (as the gusts then start approaching 200 m.p.h.)

Holmes in Cayman were designed to withstand major hurricane conditions, and Ivan flattened them, partially due to the fact that the eye wall sat over the coast for a long time Similar happened in south dade (BEFORE I came here) during Andrew


my point is that while the surge brings destruction straight from hell, lets not make the pre Andrew mistake in thinking that the winds do not cause that much damage

Points well taken......

One thing about the Homestead area that contributed to its demise was the poor construction of the homes in the area... many homes were build without the proper hurricane strapping system... still not many homes can withstand strait line winds of more than 160 for very long, even the ones designed for such wind loading.. you get more than that and its good bye home... even for the well built home... but in normal hurricanes you expect this wind force to be limited in a very small area, ... so the complete and total devastation from the winds is limited in area ... but that doesn't really matter to those who are directly impacted from it... I guess I'm still in denial relative to the degree and scope of Katrina's storm surge damages... from Pascagoula to Waveland to Slidell La, its almost total and complete devastation... and its all because of surge.... unprecedented

Final point, we just don't know how lucky we were with Katrina... what if she had not weakened and came in at a severe Cat 5!!

I just can't image the scale of destruction that Katrina would have generated had she hit the MS and LA coast with sustained winds of 175 mph... not only would you have had total devastation in areas well removed from the coast... the surge might have approached biblical levels of perhaps 40 feet plus along the entire area (one can only image what the max might have been, 50 feet?) .. Which would for all practical purposes completely submerged the entire peninsular of Biloxi and causing a complete and total annihilation of the city….

One lesson about hurricanes.... they always have the potential for being worse than what they actually were....

[Derek Ortt]

had it not have weakened, the surge would likely have been a few feet higher in MS and the wind in NO would have been to the point where many of the roofs where people took shelter would have been blown off, creating a much higher death toll


We are fortunate that Katrina weakened as fast as Lili did 3 years before. We are unfortunate that Katrina started out as a much more intense hurricane hough

[MiamiensisWx]

Why have so many storms in recent years (Isabel, Lili, Floyd, Katrina, Rita, Dennis, Ivan, Frances, etc.) tended to weaken before making landfall, whether on the Gulf coast or elsewhere?

[Scorpion]

Why have so many storms in recent years (Isabel, Lili, Floyd, Katrina, Rita, Dennis, Ivan, Frances, etc.) tended to weaken before making landfall, whether on the Gulf coast or elsewhere?

Most of them were northern Gulf Coast landfallers, and the NGOM cannot support a Cat 4 or 5. I think Isabel encountered heavy shear and dry air. Floyd entrained dry air as well. Frances was sheared pretty bad I think.

[benny]

"Most of them were northern Gulf Coast landfallers, and the NGOM cannot support a Cat 4 or 5."

Wait, why can't the NGOM support a Cat 4 or 5??? This is erroneous thinking. Why not? There are plenty of hurricanes that get really strong (Isabel 03) over somewhat marginal water and marginal depth. Dry air isn't always a problem. Saying something with an absolute is dangerous. Camille would beg to differ. 1919 LA Cat 4 would as well. It might be harder to do and take some perfect conditions..

[f5]

did they confirm that 34.9 ft value in Pass Christian?besides that what were some other high numbers

[Frank P]

go to this web page to get the NOAA surge values

http://www.ncddc.noaa.gov/website/Katri ... viewer.htm

ranges from 28 feet from the Beau Rivage Casino in Biloxi to 28 feet in Waveland to 25 plus feet at Diamonhead on I-10...

From the 28 foot surge in Waveland to the 28 foot surge in Biloxi is about 30 miles in distance... that an incredible distance for surge to be up that high....

[Audrey2Katrina]

did they confirm that 34.9 ft value in Pass Christian?besides that what were some other high numbers

Yup, and that was on a NOAA webpage too.. I believe the map to see that was posted in another thread... you could move it all over the coast, but there is one small area jutting out at Pass Christian that had a bona-fide 34 footer posted on it.

A2K

[Ixolib]

go to this web page to get the NOAA surge values

http://www.ncddc.noaa.gov/website/Katri ... viewer.htm

ranges from 28 feet from the Beau Rivage Casino in Biloxi to 28 feet in Waveland to 25 plus feet at Diamonhead on I-10...

From the 28 foot surge in Waveland to the 28 foot surge in Biloxi is about 30 miles in distance... that an incredible distance for surge to be up that high....

Man, they really need to update their map. Credibility is EVERYTHING!! They still have the Gold Shore, Lady Luck, and Biloxi Belle on the map as active casinos. All three of them went out of business long ago....

And thank goodness that 28 foot measure at the Beau didn't make it to the bay side. Otherwise, I'd have been in BIG trouble. As the crow flies, I'm only about 1.5 miles from the Beau... The 22 feet we got here at the house was way more than enough for me...

[Jim Cantore]

"Most of them were northern Gulf Coast landfallers, and the NGOM cannot support a Cat 4 or 5."

Wait, why can't the NGOM support a Cat 4 or 5??? This is erroneous thinking. Why not? There are plenty of hurricanes that get really strong (Isabel 03) over somewhat marginal water and marginal depth. Dry air isn't always a problem. Saying something with an absolute is dangerous. Camille would beg to differ. 1919 LA Cat 4 would as well. It might be harder to do and take some perfect conditions..

Shallow water

[Extremeweatherguy]

"Most of them were northern Gulf Coast landfallers, and the NGOM cannot support a Cat 4 or 5."

Wait, why can't the NGOM support a Cat 4 or 5??? This is erroneous thinking. Why not? There are plenty of hurricanes that get really strong (Isabel 03) over somewhat marginal water and marginal depth. Dry air isn't always a problem. Saying something with an absolute is dangerous. Camille would beg to differ. 1919 LA Cat 4 would as well. It might be harder to do and take some perfect conditions..

Shallow water

I am going to have to disagree on this one. If it was depth that was a problem then I guess all storms would weaken before landfall because every area of the Gulf and Atlantic has a much shallower area of water before landfall. I mean take a look at west Florida! If depth was a concern, then how did Charley explode from a 125mph Cat. 2 to a 150mph Cat. 4 in just hours?

[Lindaloo]

It all depends on the ingredients when the hurricane gets closer to shore. I am not gonna complain because they weaken before they make landfall, that is for sure!!

[Scorpion]

Heat content in the NGOM is marginal at best.

[Jim Cantore]

"Most of them were northern Gulf Coast landfallers, and the NGOM cannot support a Cat 4 or 5."

Wait, why can't the NGOM support a Cat 4 or 5??? This is erroneous thinking. Why not? There are plenty of hurricanes that get really strong (Isabel 03) over somewhat marginal water and marginal depth. Dry air isn't always a problem. Saying something with an absolute is dangerous. Camille would beg to differ. 1919 LA Cat 4 would as well. It might be harder to do and take some perfect conditions..

Shallow water

I am going to have to disagree on this one. If it was depth that was a problem then I guess all storms would weaken before landfall because every area of the Gulf and Atlantic has a much shallower area of water before landfall. I mean take a look at west Florida! If depth was a concern, then how did Charley explode from a 125mph Cat. 2 to a 150mph Cat. 4 in just hours?

Charley: No sheer, No dry air, 90 degree waters.

Katrina: Shallow water, dry air, Eyewall replacement

[skysummit]

For Katrina, I'm going to say upper Cat 4 at the VERY first landfall......over the SW Mississippi River Pass. Looking at Sat and Radar imagery, I'd say that's likely. It looks like her eye closed in immediately after that landfall so in New Orleans, upper Cat 1 winds, and the MGC Cat 2 with a very small area of Cat 3 winds.

As for why storms have been weakening prior to landfall, just perfect timing. It's ridiculous to think the NGOM cannot support a Cat 5.

[Derek Ortt]

if fact that the NGOM cannot support a cat 5 because the cold water underneath will always be upwelled. Unless we have a QG enhanced storm like Charley (the only way it neared cat 5 status), it is just not going to happen

[Frank P]

if fact that the NGOM cannot support a cat 5 because the cold water underneath will always be upwelled. Unless we have a QG enhanced storm like Charley (the only way it neared cat 5 status), it is just not going to happen

Gee I thought Camille was a Cat 5? and it was in the NGOM... and it happened I think, unless it was all a bad dream.... or....

unless it was downgraded to a Cat 4 recently.....

[Derek Ortt]

I was warned about the HURDAT dataset that has not been reanalysed. What happened was John Hope and Charlie Neumann focused mainly on track; thus, intensities are subject to VERY LARGE error. Lets wait for the reanalysis, but there is a chance that it will lose cat 5 status (and Hugo could be awarded it) as we know that the winds start to decrease before the pressure has stopped falling in the northern GOM

[Jim Cantore]

I was warned about the HURDAT dataset that has not been reanalysed. What happened was John Hope and Charlie Neumann focused mainly on track; thus, intensities are subject to VERY LARGE error. Lets wait for the reanalysis, but there is a chance that it will lose cat 5 status (and Hugo could be awarded it) as we know that the winds start to decrease before the pressure has stopped falling in the northern GOM

As in Katrina was never a 5?

That would be a shocker