Highest Katrina waves much lower than Ivan? If so, why?

[LarryWx]

I received some emails from someone suggesting that Katrina's highest waves in the GOM were MUCH lower than Ivan's. I don't understand why that would have been the case, especially since Katrina's max. winds were 10-35 mph stronger. Here are the emails:

"Highest Katrina waves I can find mentioned are 35-40 - obviously good sized, but substantially below Ivan. This is from sites where weather fans were tracking buoy data and other information on Katrina."

"One thing that they said was unique or unusual about Ivan was the level of wave action with unusually high waves, with one measured at 90+ feet (the largest ever measured for a hurricane, but the scientists believe that there may have been another as high as 132 feet)."

Does anyone know more about each storm's highest waves and does anyone have a possible explanation for Ivan's being MUCH higher, IF , indeed, that is true?

I have two ideas and am wondering if either is a possible explantion for funny data:

1) Maybe the center of Ivan went very close to a buoy while Katrina's center didn't?
2) Maybe there was a key buoy failure with Katrina vs. none for Ivan?

[wxmann_91]

I think that it's because Ivan lasted longer as a major hurricane, though Katrina was stronger. Or you could be right, no buoys to report Katrina's waves.

[cjrciadt]

Were not those 90ft waves in deeper water not at the coast? The highest from Katrina were 40, however how many buouys passed on and weather stations?

[Jeffweather]

There was a wave we found the morning of Katrina's landfall of 49 feet at the buoy south of Dauphin AL. That was the highest we could find. I didn't really look that deeply into this but perhaps there were no buoys/ functioning buoys right in the path. The really big waves would be focused right near the center of the storm.

Also when it comes to waves... finding a big one is chance because of constructive and destructive interference. Fisherman call the constructive ones "rouge" waves. During a monster storm you will see waves over 100 feet. The perfect storm off New England has such waves.

Jeff

[Jim Cantore]

We didnt hear about Ivans 90 foot waves until recently

there may be higher waves we havent heard about yet

[no advance]

Could it be Ivan was moving basically in a straight line north while Katrina moved like a fish hook.

[Aquawind]

I would think the storm surge is more than just wave hieght. With the lower pressure as you get closer to the center you can raise the water level.. kind of like a vacum sucking up water it will draw it upward until it breaks lose and goes into the vacum(although it's actually sinking air).. Hence the surge is worst near the eye for more reasons than one.

Direction and Speed do play a part as well.. Also the high winds might actually be blowing the tops off the waves..Ultimately bouy location is most likely an issue.

Ivan had it's massive circulation and strength before it even got into the gulf..

Paul

[x-y-no]

The 90-foot waves in Ivan were measured by an array of sensors on the bottom, not by a bouy.

Chances are, we don't have that data yet for Katrina.

[x-y-no]

I would think the storm surge is more than just wave hieght. With the lower pressure as you get closer to the center you can raise the water level.. kind of like a vacum sucking up water it will draw it upward until it breaks lose and goes into the vacum(although it's actually sinking air).. Hence the surge is worst near the eye for more reasons than one.

Direction and Speed do play a part as well.. Also the high winds might actually be blowing the tops off the waves..Ultimately bouy location is most likely an issue.

Ivan had it's massive circulation and strength before it even got into the gulf..

Paul

Pressure accounts for at most a couple of feet of surge. One atmosphere is approx. 30 feet of water, so a 900mb storm could in theory have 3 feet of pressure-related surge. In practice, it's generally less because the motion of the storm mitigates against reaching the theoretical maximum.

[SIMWMBA]

Likely IF Ivan's wave heights were bigger it was a direct result more of the longer fetch (unobstructed distance and duration over open water) than of just the wind speed alone.

Ivan's course was a slow curve, AND it was already a Cat 5 much farther south (right?) Katrina's course involved that 'sharp' NW turn and it reached Cat 5 much closer to the coast.

The biggest wave height recorded by surface bouy 42040 in the GoM with Ivan was about 54' just before the NW eyewall approached it.
http://meted.ucar.edu/marine/mod2_wlc_gen/print.htm

The last I saw from the same bouy with Katrina (as it tracked about 50+ miles farther west) the seas were near 40'.

It will be interesting to see what the seabed sensors tell about Katrina's max wave heights.

[Aquawind]

The 90-foot waves in Ivan were measured by an array of sensors on the bottom, not by a bouy.

Chances are, we don't have that data yet for Katrina.

Thanks for clariying the pressure related surge. Do you have a good link for the details and data from these sensors?

Paul