Cat 4 hurricanes very unlikely north of Florida on E Coast

[Derek Ortt]

in Katrina, and Wilma, the max winds were at about 700mb, indicative of some baroclinic influence. In addition, the region of max winds were very borad

Regarding the HRD maps, the ONLY take into account the sustained winds. The 1.4-1.6 wind to gust ratio and its variability is not factored in at all in those maps

Katrina should serve as a lesson in that "only" a 3 is unbelievably destructive, and that even "just" a cat 1 storm, can produce gusts well over 120 m.p.h.2 (the instruments on the roof of my office had gusts over 110 during Wilma, but sustaiend winds just over 80)

[Pearl River]

Opal storm wrote

Storm surge is not categorized,so there is no such thing as a "cat 5 storm surge".

Tell that to the pro-mets that do state there is such a thing.

I think HRD is accurate for the most part,and a good tool for people to look at and see what winds they actually experienced during a hurricane.I think the Katrina map is right.

Accurate if Se LA were a solid land mass where friction could account for that, but since this are is mostly watery marsh, I doubt the frictional effects are that great. Besides, the delta is only a few miles wide as far as "solid land" is concerned.

It's your opinion and you're entitled to it, as is the opinion's we hold. Remember, even the pro's cannot agree on everything.

[Audrey2Katrina]

I challenge the HRD people to personally come on down to the coast,

Spittin' in the wind, MGC... quite literally.. did you notice how WIDELY that contour of Cat 3 is around Plaquemines? That area literally down to the MOUTH of the River is MUCH narrower than what those lines show...so they don't think Cat 3 even reached ANY land area in Louisiana at first landfall. it's Cat 2 even over WATER down there ... ummm... sorry... that's beyond unbelievable IMO... but this is, sad to say, just rehashing the same dead-horse we beat to death in umpteen other threads, and this is NOT where I wanted this to go. The discussion is about Category 4 storms being "very unlikely" north of Florida on the E. Coast. But these things do have a way of taking on a life all their own. My only beef is the dogmatism that some seem to embrace whenever this topic is broached. I'm willing to allow for room for error; but there are those who won't budge an inch.

Oh well... C'est la vie, in the Northern Gulf.

A2K

[gatorcane]

I challenge the HRD people to personally come on down to the coast,

Spittin' in the wind, MGC... quite literally.. did you notice how WIDELY that contour of Cat 3 is around Plaquemines? That area literally down to the MOUTH of the River is MUCH narrower than what those lines show...so they don't think Cat 3 even reached ANY land area in Louisiana at first landfall. it's Cat 2 even over WATER down there ... ummm... sorry... that's beyond unbelievable IMO... but this is, sad to say, just rehashing the same dead-horse we beat to death in umpteen other threads, and this is NOT where I wanted this to go. The discussion is about Category 4 storms being "very unlikely" north of Florida on the E. Coast. But these things do have a way of taking on a life all their own. My only beef is the dogmatism that some seem to embrace whenever this topic is broached. I'm willing to allow for room for error; but there are those who won't budge an inch.

Oh well... C'est la vie, in the Northern Gulf.

A2K

Fortunately for those along the northern GOM, you have the luxury of the westerlies that typically stay entrenched most of the summer not to mention the loop current does not make it that far north. In addition, as hurricanes approach the northern GOM, they tend to wrap in drier air from the north further weakening a CAT 4+ system. Usually that starts to happen when the eye is below 100 miles from the coast.

If you watch Katrina, it is amazing how quickly she was weakening as she got close to the coast - although certainly a formidable hurricane which managed to break the levy system that caused most of the damage - it could have been CAT 3+ for much more than what we saw.

Now of course, this thread is about the EC not the northern GOM so we should stay on that topic.

[Derek Ortt]

I understand how hard it is to accept soemthing different from the origional accepted fact

When Dan Stern showed me the profiles of Katrina indicating a marginal 3 at landfall, I thought he was nuts. But I was able to determine that he was correct after opening my eyes and actually looking at the data, and that my firm initial belief that Katrina was a strng 4 at both landfalls was nothing short of a fallicy

[Opal storm]

Well I guess it's my fault since this HRD argument started when I said "N.O saw cat 1 conditions",I'll try and keep my mouth shut next time lol.

[Pearl River]

Ivanhater wrote

I remember all the same discussions after Ivan, and at first I took it personally, how could some "pro met" or anyone else for that matter sit back and tell me we only had this or that in Pensacola when Most of my family lost everything on Pensacola beach(and some are still living in Gulf Breeze waiting to build back on the beach) but the destruction speaks for its self and now I let those trivial things roll of my back...so I sympathize with yall.

You know Ivan, it's not so much the trivial things. When someone shows that HRD analysis map and states it for gospel, I do have a problem. Considering the delta isn't even close to the width they show it to be. It's not even land area that would cause that great a friction reduction. I can respectfully disagree with it.

[Ivanhater]

Ivanhater wrote

I remember all the same discussions after Ivan, and at first I took it personally, how could some "pro met" or anyone else for that matter sit back and tell me we only had this or that in Pensacola when Most of my family lost everything on Pensacola beach(and some are still living in Gulf Breeze waiting to build back on the beach) but the destruction speaks for its self and now I let those trivial things roll of my back...so I sympathize with yall.

You know Ivan, it's not so much the trivial things. When someone shows that HRD analysis map and states it for gospel, I do have a problem. Considering the delta isn't even close to the width they show it to be. It's not even land area that would cause that great a friction reduction. I can respectfully disagree with it.

Completely understand

[Audrey2Katrina]

Regarding the HRD maps, the ONLY take into account the sustained winds.

Exactly, which is how storms are categorized by SS... and it shows NO sustained winds over actual landfall in Louisiana at Cat 3, which is more than slightly absurd... especially in light of the fact that the "official" NHC report alleges that it was a "high-end" Cat 3 at first LANDfall in Louisiana, and maintained that to second landfall... this map is in stark contrast even to measured sustained winds at Michoud... sorry, but with all due respect, I can't remotely consider it a reliable source. Nice, and pretty--just inaccurate as far as I can see.

A2K

[Pearl River]

Gatorcane wrote

Fortunately for those along the northern GOM, you have the luxury of the westerlies that typically stay entrenched most of the summer not to mention the loop current does not make it that far north. In addition, as hurricanes approach the northern GOM, they tend to wrap in drier air from the north further weakening a CAT 4+ system. Usually that starts to happen when the eye is below 100 miles from the coast.

If you watch Katrina, it is amazing how quickly she was weakening as she got close to the coast - although certainly a formidable hurricane which managed to break the levy system that caused most of the damage - it could have been CAT 3+ for much more than what we saw.

Now of course, this thread is about the EC not the northern GOM so we should stay on that topic.

One thing should be noted gator, Katrina on satellite and radar presentation appeared to be strengthening as it approached the Pearl River.

Take a look at these 2 vortex messages. Notice anything. A 7kt increase once it moved overland.

URNT12 KNHC 291500
VORTEX DATA MESSAGE
A. 29/14:42:40Z
B. 30 deg 11 min N
089 deg 36 min W
C. NA mb NA m
D. NA kt
E. NA deg nm
F. 179 deg 120 kt
G. 097 deg 019 nm
H. 928 mb
I. 18 C/ 2435 m
J. 19 C/ 2435 m
K. 19 C/ NA
L. OPEN SW
M. E210/35/25
N. 12345/NA
O. 0.12 / 2 nm
P. AF306 2112A KATRINA OB 30
MAX FL WIND 120 KT E QUAD 14:36:40 Z
MAX FL TEMP 20 C, 99 / 13NM


URNT12 KNHC 291527
VORTEX DATA MESSAGE
A. 29/15:16:50Z
B. 30 deg 19 min N
089 deg 38 min W
C. 700 mb 2497 m
D. NA kt
E. NA deg nm
F. 178 deg 127 kt
G. 90 deg 031 nm
H. EXTRAP 932 mb
I. 11 C/ 3049 m
J. 17 C/ 3049 m
K. 17 C/ NA
L. OPEN SW
M. C33
N. 12345/ 7
O. 0.02 / 1 nm
P. AF300 2212A KATRINA OB 28
MAX FL WIND 127 KT E QUAD 15:06:20 Z
SLP EXTRAP FROM 700 MB
FIX MADE OVERLAND
EYE RAGGED

[Ixolib]

I almost feel compelled to offer my repeated opinion in this thread, but as has been demonstrated time and again since August 29, it simply boils down to this...

For those who were never personally and directly impacted by Katrina, the results of that event can only be sketched out on computers, analyzed on maps, and debated in threads such as this - much of which leads to absolute conclusions of a non-associated viewpoint. But for those of us who not only lived through the storm, but survived, our lives have forever changed in ways so profound that those on the "outside" will never, never, never understand. That is, of course, until they themselves experience a similar might as brought on by the great storm of 8/29/05. Perhaps then, HRD, SLOSH models, SS scales, and other like evidence will assume a lesser place on their hierarchy of concrete fact.

A2K, Frank, MGC, PR, and others of the same vane - you have my admiration for your tireless persistence in the repetitive face of these types of threads - the numbers of which seem to grow on a daily basis...

[gatorcane]

I almost feel compelled to offer my repeated opinion in this thread, but as has been demonstrated time and again since August 29, it simply boils down to this...

For those who were never personally and directly impacted by Katrina, the results of that event can only be sketched out on computers, analyzed on maps, and debated in threads such as this - much of which leads to absolute conclusions of a non-associated viewpoint. But for those of us who not only lived through the storm, but survived, our lives have forever changed in ways so profound that those on the "outside" will never, never, never understand. That is, of course, until they themselves experience a similar might as brought on by the great storm of 8/29/05. Perhaps then, HRD, SLOSH models, SS scales, and other like evidence will assume a lesser place on their hierarchy of concrete fact.



A2K, Frank, MGC, PR, and others of the same vane - you have my admiration for your tireless persistence in the repetitive face of these types of threads - the numbers of which seem to grow on a daily basis...

To support the other side, you are missing the point - a CAT 2/3 can be very bad so we should not underestimate that but we are saying that you did not receive anything higher than CAT 2/3....the data shows this, however, we do understand it was a formidble storm and should NEVER be downplayed.

[Pearl River]

Derek wrote

understand how hard it is to accept soemthing different from the origional accepted fact

When Dan Stern showed me the profiles of Katrina indicating a marginal 3 at landfall, I thought he was nuts. But I was able to determine that he was correct after opening my eyes and actually looking at the data, and that my firm initial belief that Katrina was a strng 4 at both landfalls was nothing short of a fallicy

I'll agree with you Derek on that point. But when looking at the HRD analysis the problem with it, the land contours aren't even close to the actual size of the land mass. It tells me there was no cat3 wind on an area of land that is at most 20 miles across and then cat3 on the other side. That's the issue I have.

[Derek Ortt]

Instead of saying that just because the data says a storm was "only" a cat 3 or a 3, and not a 4 or a 5, that the storm is being downplayed, IMO, it would be betetr if we in light of the extensive data analysis were able to convey to the masses that Katrina was an example of what a cat 3 can do, and that those are likely going to destroy your home.business and threten our life. Cat 3's are major hurricanes for a reason

[Audrey2Katrina]

I understand how hard it is to accept soemthing different from the origional accepted fact

Exactly, about as hard as it is to accept that sometimes the "revised" facts turn up to be just as inaccurate.

The reason I asked about the highest possible gust at around 850 mb in Katrina is because I have recon datat showing a 234 Kt gust in Katrina at a BL about 600 m above the Gulf...pretty incredible if you ask me... and another dropped INLAND between Pass Christian and Henderson Point showing winds at 133 Kts.. 350 m up. A fairly impressive report by one who actually FLEW into Dennis, Rita, AND Katrina... and for whatever it's worth, I think he gives a VERY plausible explanation for the case that Katrina was still a 4 at first landfall... Frankly I believe it.


As to Cat 4's North of Florida along the E coast... they doubtless are "rare"... but that really doesn't mean much beyond playing with statistics, because it only takes one!

A2K

[Pearl River]

Gatorcane wrote

Ixolib wrote:
I almost feel compelled to offer my repeated opinion in this thread, but as has been demonstrated time and again since August 29, it simply boils down to this...

For those who were never personally and directly impacted by Katrina, the results of that event can only be sketched out on computers, analyzed on maps, and debated in threads such as this - much of which leads to absolute conclusions of a non-associated viewpoint. But for those of us who not only lived through the storm, but survived, our lives have forever changed in ways so profound that those on the "outside" will never, never, never understand. That is, of course, until they themselves experience a similar might as brought on by the great storm of 8/29/05. Perhaps then, HRD, SLOSH models, SS scales, and other like evidence will assume a lesser place on their hierarchy of concrete fact.



A2K, Frank, MGC, PR, and others of the same vane - you have my admiration for your tireless persistence in the repetitive face of these types of threads - the numbers of which seem to grow on a daily basis...


To support the other side, you are missing the point - a CAT 2/3 can be very bad so we should not underestimate that but we are saying that you did not receive anything higher than CAT 2/3....the data shows this, however, we do understand it was a formidble storm and should NEVER be downplayed.

The data also shows New Orleans did not receive anything more than cat1. I'll repeat it, and yes they are "unofficial":

EASTERN NEW ORLEANS - NASA MICHOUD FACILITY WIND EQUIPMENT 40 FT
GAGE 1 PEAK WIND 84 KT 1059UTC
GAGE 2 PEAK WIND 107 KT 1415UTC
VISUAL OBSERVATION OF READOUT DISPLAY FROM GAGE 2




84kt=96.6mph-cat2
107kt=123.05mph-cat3

This is eastern New Orleans. A little geography lesson-Orleans Parish=city of New Orleans.

[Audrey2Katrina]

Katrina was an example of what a cat 3 can do,

Derek, I could completely agree with you on this point; but the HRD map does NOT show a Cat 3 anywhere over anything but water in La... and frankly that flies in the face of logic itself. Anyone who believes that NO inland area of Louisiana had worse than Cat 2 winds --and precious FEW had that... well then they need to start printing out deeds to the Brooklyn Bridge IMHO.

A2K

[Frank P]

in Katrina, and Wilma, the max winds were at about 700mb, indicative of some baroclinic influence. In addition, the region of max winds were very borad

Regarding the HRD maps, the ONLY take into account the sustained winds. The 1.4-1.6 wind to gust ratio and its variability is not factored in at all in those maps

Katrina should serve as a lesson in that "only" a 3 is unbelievably destructive, and that even "just" a cat 1 storm, can produce gusts well over 120 m.p.h.2 (the instruments on the roof of my office had gusts over 110 during Wilma, but sustaiend winds just over 80)

The primary reason Katrina was SO destructive was NOT because of her Cat 3 winds, it was BECAUSE OF HER SURGE...... period....

So what we have here is a disconnect between categories, surge and wind.... case in point... every house on my block that was destroyed was destroyed by the storm surge...WATER... every house in my neighborhood that was severly damaged was also due to WATER... this can be said for many many other neighborhoods throughout MS... you can BUILD a house to WITHSTAND Cat 3 hurricane winds... 125 mph winds DO NOT destroy houses built to the Internation Building Codes...... gee, I don't know how many times I've said this...

Fact.... of the 60 employees at my company who lost everything they owned 59 of the 60 lost their homes and everything to WATER.... only one lost their home to wind, and it was from a tornado, and inland off the coast.... of the 40 employees who suffered severe home damage, 35 of the homes were damaged to WATER.... only 5 can be attributed to wind...

[Furious George]

Instead of saying that just because the data says a storm was "only" a cat 3 or a 3, and not a 4 or a 5, that the storm is being downplayed, IMO, it would be betetr if we in light of the extensive data analysis were able to convey to the masses that Katrina was an example of what a cat 3 can do, and that those are likely going to destroy your home.business and threten our life. Cat 3's are major hurricanes for a reason

Can't emphasize that point enough. A Cat 3 can leave nothing but a slab in place of what used to be a house. In a case such as that, what really is the difference between a Cat 3, 4 or 5?

Having drove around Cameron, LA after Rita passed, I can say this. If I would have not known the storm magnitude and you asked me to guess the Category of Hurricane damage I saw near Cameron, I would have said "Cat 4 or Cat 5, no question". It was completely devastating. But you know what - that is what Cat 2 and Cat 3 storms as capable of! Wiping out everything. After last season, I have a new found respect for hurricanes, especially "just Cat 2 or 3's".

[Frank P]

Instead of saying that just because the data says a storm was "only" a cat 3 or a 3, and not a 4 or a 5, that the storm is being downplayed, IMO, it would be betetr if we in light of the extensive data analysis were able to convey to the masses that Katrina was an example of what a cat 3 can do, and that those are likely going to destroy your home.business and threten our life. Cat 3's are major hurricanes for a reason

Can't emphasize that point enough. A Cat 3 can leave nothing but a slab in place of what used to be a house. In a case such as that, what really is the difference between a Cat 3, 4 or 5?

Having drove around Cameron, LA after Rita passed, I can say this. If I would have not known the storm magnitude and you asked me to guess the Category of Hurricane damage I saw near Cameron, I would have said "Cat 4 or Cat 5, no question". It was completely devastating. But you know what - that is what Cat 2 and Cat 3 storms as capable of! Wiping out everything. After last season, I have a new found respect for hurricanes, especially "just Cat 2 or 3's".

They build modular homes made out of standard wood construction and actually wind test them at 150 mph, and they ARE NOT DESTROYED....