Will there be a debate on Katrinas intensity at landfall?

[Hurrilurker]

She was not weaking at landfall. The whole western quad had rewraped at lanfall. In the storm was becoming alot more organized. Given more time she would of been back where she was earlier.

Still had an open eyewall, reducing winds and rising pressure up to landfall, and dry air entrainment visible. After the first landfall she may have been trying to strengthen again but ran out of water. I guess you need to decide the time period over which you decide it's weakening or strengthening too: is it 15 minutes or 12 hours, for example?

[NastyCat4]

There are a lot of "armchair meteorologists," who rely on singular data to vindicate their forecasts and opinions. One can get data to support almost anything. Those of us who've actually experienced hurricanes know that Katrina was no "Cat 3" in the New Orleans area--that was not the case, no matter what the data sample says. Once again, the numbers don't always correlate, and this is a perfect example. Katrina was stronger than Camille--end of story.

[Matt-hurricanewatcher]

I saw that Katrina's surge was 31 feet. Which is by far the highest surge ever to hit the United states. Also that surge did not go down from when it was 175 mph hurricane. Yes the surge that hit was 175 mph hurricane surge. Data out of recon shown that the storm at first landfall was 140 to 145 mph winds. Which is a soild cat4. You also have to remember that the hurricane force winds on this sucker was 105 miles/230 tropical storm force.

For a time a few hours before landfall the western end did get sheared/dry air. But soon after that the western side had rebuilt its self jsut as it was making landfall. Also it shown that the outter eye had tooken over. This system also looked to be holding its own as it went over that small area of land. In maybe just maybe got a little stronger then the 125 mph at second landfall. Maybe 130 to 135 mph.

What you have to remember Ivan was only 120 mph at landfall. In he was weaking. The Hrd data shown 95 or so knots=110 mph. But recon supported a soild cat3 115 to 120 mph...

Katrina had record surge for any hurricane to have ever hit the United states by far. In it could of been higher then the 31 feet. If I was reading it right Camille had 24 feet surge. So Katrina blow it away.

So for one Katrina was a cat4...Strongest hurricane since Camille. In thats winds. Record surge that done the main damage. Winds are not the killer its the surge that made 1900 hurricane what it was.

[senorpepr]

There are a lot of "armchair meteorologists," who rely on singular data to vindicate their forecasts and opinions. One can get data to support almost anything. Those of us who've actually experienced hurricanes know that Katrina was no "Cat 3" in the New Orleans area--that was not the case, no matter what the data sample says. Once again, the numbers don't always correlate, and this is a perfect example. Katrina was stronger than Camille--end of story.

First, I hope you're not putting that "armchair meteorologist" tag on us professionals here. This is a science that we've invested a large amount of time and effort studying. This isn't some "armchair" passion. This isn't about finding some data to verify our forecasts. This is about improving forecasts, educating people, and saving lives.

Secondly, I don't believe anyone said this was a category three. It was clearly a category four, based on wind speeds, which is what the Saffir-Simpson scale uses.

Third, yes Katrina was only stronger than Camille in terms of storm surge (which hadn't decreased thanks to laws in hydraulics) and pressure. However, Camille was stronger in winds (thanks to pressure gradient) which is why she was a category five whereas Katrina was a four.

Finally, this isn't hunting and pecking for data to prove us right. You're entitled to your opinion, but that doesn't make you right. Every amount of data available says this is a category four. Just because you live by the coast doesn't make you a professional in this matter. Please accept that. Just because I live next to a hospital doesn't make me a doctor.

You can chose to accept these facts or not...I really don't care. I am just trying to educate people on these facts, since it's something I do every day as a part of my job.

[shaggy]

isabel is a classic case of a storm with low pressure and high winds being reported from recon that never made the transition to the ground.On approach isabel had flight level winds of 140 but surface was only 110 or so if even that.I went thru the SW side of the eye got calm for about 15 minutes and we never had winds higher than 60mph gusts.Pressure got to 954mb here with 60mph gust go figure that one out?Katrinas low pressure doesn't gaurantee she was a 5 or anything else.Just mean she was a bad hurricane but the bad part is is that nobody will probably know for sure since most reporting stations didn't make it and could not provide accurate surface wind obs!

[Wthrman13]

I'd like to add in to this discussion by saying that I agree completely with what the other meteorologists here have been saying. It's quite clear from all the data, which I was raptly staring at during the final 6 hours before Katrina's landfall, that the storm was not a Category 5 even that far out from landfall. "But what about the low pressure?", you ask. Katrina was a large storm, much larger than Andrew and even Camille, and furthermore, it's pressure gradient was "divvied up" amongst three concentric eyewalls, so that the inner eyewall was not as strong as it would have been otherwise. If these outer eyewalls had not formed, the inner core winds would have been much stronger. The data speak for itself, by the wind speed criterion used to classify hurricanes, Katrina was a Category 4 at landfall. They have more and better instruments than they did back with Andrew, and all the instruments agree on this. Also, as everyone else has been saying, the storm surge was clearly of Category 5 caliber, but again this was because it had built up over time in the 24-36 hours before Katrina made landfall. Since the weakening was very slow at first, and because it was picking up speed, the surge did not have time to lower that much. It's likely the surge would have not been nearly as bad had Katrina never made it to Category 5 to begin with. Almost all the damage I've seen on the news appears to have been caused by surge and flooding. The wind damage is there, but nothing compared to the former two causes.

NO ONE is trying to downplay this by saying Katrina was only a Cat 4. In fact, this will serve as a wakeup call, that even a Category 4, hitting in the right place, can cause a major catastrophe. So let's put this to rest folks. There may be some minor adjustments to the landfall winds, but I would be very surprised if they bumped it back up to 5 at landfall. The wind data from multiple sources simply does not support it.

Katrina was not more intense than Andrew, but certainly more deadly and a far worse disaster.

[Jim Cantore]

Katrina is simalar to Ivan and Opal both whose surge exeeded their wind intensity

As for Wind intensity that will have to be decided by wind reports in the Pilottown Louisana area (in the southeast tip) and I dont think any equipment was set up there (or even survived) The wind data from there might be the deciding factor.

Camille actully had the surge of a weaker storm (this is obvious when you compare Camille and Katrina)

Isabels surge was a remnent of its old strength

But why was Dennis surge so minor when it was just brought down from 145 hours before landfall?

[Derek Ortt]

isabels surge was normal for a large cat 2

surge is also a function of size, not just wind speed

There is credible NOAA data suggesting cat 3, and credibly Air Force data indicating a cat 4. I have looked at the sondes from Aug 27, when Katrina was reported as a cat 3 with 100KT winds and a 945mb pressure. Not one sonde suggests anything more than <b>CAT 1</b>. The boundary layer reduction in the high wind regime was much mroe severe than usual. But of course, the some of the real arm-chair mets on here, not the professional meteorologists, will overlook or not understand this fact, plus the air force flight level wind data, and continue to state that Katrina was a category 5 hurricane at landfall.

the debate over a 3 vs 4 should be had, and is within the scientific community already as it could shed some light on the very little understood boundary layer dynamics of the inner-core in a major hurricane

[Matt-hurricanewatcher]

It appered that the same thing that weaken Lili,Ivan,Dennis then now Katrina. I think when the trough/weakness is picking these systems up it pushs the western quad in. In pushs dry air/shear into the core of the cyclone. But Katrina seemed to try to come back at the last minute. But in which chocks off the outflow to the cyclone in which weakens it.

Looking at damage it appears around 140 at first landfall...About as bad a Charley damage(Winds alone) The surge makes some areas look like the Tsunumi.