Historic Multi Day Tornado/Flooding Event 4/23-28/2011

[RL3AO]

Wow, two EF-5's for Mississippi. Bet ya, Mississippi is the only state to be hit by EF-5 tornado and Cat-5 hurricane......MGC

You're right no EF-5s, but Florida has been hit by F4's which had winds in excess of 200mph + in the 50s and 60s which if converted would be comparable to the recent MS EF5s. And of course we all know about Andrew and the Labor Day cane.

Technically its not comparable. The Fujita scale is a damage scale. EF4 damage compares with F4 damage. Engineers found that Fujita was overestimating the wind speed needed to cause certain damage.

[brunota2003]

They could raise the surface level though? Have those reinforced rooms ever been tested in an EF4 or EF5 tornado?

That one the lady in Moore OK built was about the only thing left standing in her neighborhood after an EF5.

Actually, the one in Moore is the same tornado that the 300+ mph winds right off the surface were measured in by the DOW truck. Can they survive? Yes.

[badger70]

Found a cool link to satellite imagery by quadrangles of Alabama tornado damage:

http://ngs.woc.noaa.gov/storms/apr11_tornado

[RL3AO]

We have quietly passed the Super Outbreak with I believe 155 tornadoes in one day.

Of course I can guarantee you that the Super Outbreak had more tornadoes. If you look at the numbers in modern day tornado outbreaks compared to older ones you notice how there is a much larger percentage of (E)F 0's and 1's now. Its a simple explanation. You have chasers and spotters everywhere on every thunderstorm.

Quick example.
Note: Weak tornado = 0 or 1 on either scale. Violent tornado is 4 or 5.
Super Outbreak: 35% weak, 20% violent
Super Outbreak II: 70% weak, 5% violent

[CrazyC83]

Agreed that I believe that April 3, 1974 had far more than 148 tornadoes. My guess is about 200 to 250, of which virtually all the missing tornadoes were F0 or F1 and not surveyed or passed over as wind damage.

[CrazyC83]

http://blogs.courant.com/connecticut_in ... -from.html

Insured damage from the outbreak: up to $5.5 billion. If the 2-to-1 rule of tropical cyclones also applies here, total damage would be as high as $11 billion! That would be BY FAR the costliest severe weather event ever.

[WeatherGuesser]

(Reuters) - Tornadoes that swept through southern U.S. states last month could cost the insurance industry up to $6 billion, risk-modeling agency RMS said on Tuesday.

The tornadoes, which struck Alabama and neighboring states in late April, will cause insured losses of $3.5-$6.0 billion, according to an initial estimate from RMS.

http://www.reuters.com/article/2011/05/ ... 22&sp=true

NSSL has released an image documenting the rotation tracks of the devastating tornadoes on April 27. Bright reds and yellows show more intense circulations.

The image of the rotation tracks was produced by the On Demand Severe Weather Verification System, part of NSSL’s Warning Decision Support System – Integrated Information (WDSS-II) Multi-Radar/Multi Sensor platform. On Demand is a web-based tool that can be used to help confirm when and where severe weather occurred.

Balance of article: http://www.norman.noaa.gov/wp-content/u ... n-U.S..jpg

Large image (869Kb, 1,920 x 1,093) at the link: http://www.norman.noaa.gov/wp-content/u ... n-U.S..jpg

KMZ file for Google Earth: http://ondemand.nssl.noaa.gov/RotationT ... 085936.kmz

[CrazyC83]

That is $12B in total damage if the rule is applied. Even if it was a hurricane that would be in the top 15 worst storms.

[ravyrn]

A dog blown away and lost during one of the Tornados in Alabama crawls back home with two broken front legs after over 2.5 weeks missing

Truly an amazing story. I can't figure out exactly how long the dog was actually missing after the storm. In different articles it has been reported as 2.5 weeks, 3 weeks, and 23 days.

[RL3AO]

DeKalb County tornado has been upgraded to EF5 making four EF5s that day and six for the year.

[CrazyC83]

There was no EF5 damage in Alabama from the Smithville tornado? If so, that would be the first time I believe that a state had three EF5's in a single day.

[Cyclenall]

DeKalb County tornado has been upgraded to EF5 making four EF5s that day and six for the year.

Pure insanity, just that. And I still think 1 or 2 more could have been EF5's which would pretty much put April 27 on the platform to SO. It's amazing to see they are still investigating that day pretty intently which is well due but research should go on for decades on this one.

I still haven't made an official post on what my thoughts are on the aftermath of this because things just got too crazy afterwards.

[CrazyC83]

DeKalb County tornado has been upgraded to EF5 making four EF5s that day and six for the year.

Pure insanity, just that. And I still think 1 or 2 more could have been EF5's which would pretty much put April 27 on the platform to SO. It's amazing to see they are still investigating that day pretty intently which is well due but research should go on for decades on this one.

I still haven't made an official post on what my thoughts are on the aftermath of this because things just got too crazy afterwards.

It may have been more violent than the 1974 Super Outbreak, as it is possible some of the tornadoes then were rated too high as they didn't have as strict standards for looking at engineering then. Some of the F4s may have been F3s, for example.