If NOAA data is correct, Katrina could have been much worse

[baygirl_1]

Ivan's surge looked like marginal cat 3 surge for the northern GOM. Alabama's surge from Katrina was as high, if not higher than what Ivan caused in the landfall zone

Derek--
The local news media here has been referring to the flooding/storm surge here as historic. Unofficial reports from folks living near Mobile Bay and the Gulf support this. We have family and friends who live on Fowl River and their homes did not flood in Georges, Danny, Ivan, or Frederic (which had no real storm surge at all). However, they are now shoveling several inches to a foot of mud out of their homes after Katrina. I'm not sure how it compares to storms in centuries past (though news media says it is perhaps the worst), but it was the worst storm surge of all storms in the recent past.

[Derek Ortt]

yeah,

Katrinas surge in Alabama is the highest I have seen there as well.

Exactly why I was SO GD ADAMENT after Ivan last year that the region only saw a marginal cat 3 or a strong cat 2 hurricane at the very most, not a borderline cat 3/4. People have now seen just how horrific a real major hurricane is

[baygirl_1]

Here's some data I found on the Mobile NWS website:

D. STORM TIDES...
HIGHEST TIDES OCCURRED ON AUGUST 29 2005 TIDES ARE GIVEN IN
MSL...
MOBILE STATE DOCKS (MBRA1) 11.45 AT 1848 UTC
USS ALABAMA (ESTIMATED) 12.00
DAUPHIN ISLAND (DAUA1) 6.63 AT 1645 UTC
DAUPHIN ISLAND (DPIA1) 6.23 AT 1542 UTC
PERDIDO PASS (PPSA1) 5.81 AT 1336 UTC
PENSACOLA (PENF1) 5.37
DESTIN (EPSF1) 4.52 AT 1336 UTC
SANTA ROSA SOUND (FWLF1) 4.10 AT 1654 UTC

ESTIMATED STORM TIDES WERE 10 TO 13 FEET IN MOBILE COUNTY
9 TO 11 FEET IN BALDWIN COUNTY
7 TO 9 FEET IN ESCAMBIA COUNTY
5 TO 8 FEET IN SANTA ROSA COUNTY
4 TO 6 FEET IN OKALOOSA COUNTY

E. BEACH EROSION...

MAJOR BEACH EROSION OCCURRED FROM DAUPHIN ISLAND TO EAST OF
DESTIN.

F. FLOODING...

STORM TIDE FLOODING OCCURRED ON DAUPHIN ISLAND WITH THE WEST END OF THE ISLAND COMPLETELY SUBMERGED. BETWEEN FORT MORGAN AND PERDIDO KEY A FEW BREACHES OCCURRED. BREACHES ALSO OCCURRED ON SANTA ROSA ISLAND IN NORTHWEST FLORIDA. BAYOU LA BATRE HAD MAJOR FLOODING FROM THE STORM TIDE. THE CAUSEWAY AND DOWNTOWN MOBILE SAW NEAR RECORD STORM TIDES (ONLY POSSIBLY EXCEEDED BY THE 1916 HURRICANE). THIS RECORD SURGE WAS PREDICTED BY THE MOBILE NATIONAL WEATHER SERVICE OFFICE TWO DAYS BEFORE KATRINA MOVED ASHORE. FLASH FLOODING OCCURRED IN SOUTHWEST ALABAMA AND SOUTHEAST MISSISSIPPI BUT ONLY LASTED FOR A COUPLE OF HOURS DUE TO THE FAST MOVEMENT OF KATRINA.

Here's the URL if you want to check out the entire post-storm report:
http://www.srh.noaa.gov/mob/0805Katrina/

[docjoe]

If I remember correctly upper parts of Escambia Bay had close to 18 feet of surge with Ivan. If this is true isnt that on the order of Cat 5?? I personally know people in the east Miltonarea(well inland) who climbed into their attics and onto their rooftops to escape the water.

docjoe

[Brent]

If I remember correctly upper parts of Escambia Bay had close to 18 feet of surge with Ivan. If this is true isnt that on the order of Cat 5?? I personally know people in the east Miltonarea(well inland) who climbed into their attics and onto their rooftops to escape the water.

docjoe

It's close... Ivan WAS a Cat 5 in the SE GOM 36 hours before landfall...

[WXBUFFJIM]

With Katarina being a category 5 for a fairly long period of time and also the very large size of the storm helped to contribute to the record setting storm surge. Katarina was even larger in size than Camille, thus even with Katarina weakening to a cat 3 and 4 just prior to landfall, it didn't matter. While it could have been worse in New Orleans, Katarina sure proved that we didn't need a direct hit to cause the chaos that we're dealing with in the big easy tonight.

Certainly my thoughts and prayers go out to the victims. Life comes first. As soon as I know that everyone here is ok, I'll feel alot better.

[WXBUFFJIM]

With Katarina being a category 5 for a fairly long period of time and also the very large size of the storm helped to contribute to the record setting storm surge. Katarina was even larger in size than Camille, thus even with Katarina weakening to a cat 3 and 4 just prior to landfall, it didn't matter. While it could have been worse in New Orleans, Katarina sure proved that we didn't need a direct hit to cause the chaos and unprecedented floods in the big easy tonight.

Certainly my thoughts and prayers go out to the victims. Life comes first. As soon as I know that everyone here is ok, I'll feel alot better.

[StrongWind]

In general

1. Will a larger (size) storm have a larger/smaller/same size storm surge as a smaller storm of the same magnitude?

2. Will a faster moving storm have a larger/smaller/same size storm surge as a slower moving storm of the same magnitude?

3. How will the storm surges compare between two storms that hit with equal magnitude cat 3 winds & pressure but one had been cat 5 weakening shortly before landfall and the other being cat 1 and strengthening?

[docjoe]

To me thesaffir simpson scale is not a truly accurate way to measure a storms potential. I lived through Ivan and I do agree with Derek Ortt's assessment of the windspeed (mainly because he has more hurricane knowledge in his little finger than I have at all). However the surge here and the damage is beyond a category 2/marginal 3. Hopefully those more well versed in these things than I am can devise some type of system that more accurately represents a storm rather than primarily relying on windspeed.

docjoe