Skip to comments.New Engineering Study Finds No EF5 Damage in Joplin
Posted on 06/10/2013 10:11:45 AM PDT by Colonel Kangaroo
JOPLIN, Mo. A new engineering study of the damage caused by the May 2011 tornado that struck Joplin found no evidence that it was an EF5, as the National Weather Service found, because the city's homes and businesses weren't built to withstand wind speeds that strong, making such a determination impossible.
The study by the American Society of Civil Engineers found that more than 83 percent of the damage on May 22, 2011, was caused by winds of 135 mph or less, which is equal to the maximum wind speed of an EF2 tornado, and that about 13 percent of the damage was caused by winds of 138-167 mph, consistent with an EF3 tornado. Only 4 percent of the damage was indicative that it had been an EF4 tornado, which can have winds speeds ranging from 168 to 199 mph, the report said.
The ASCE team also found that while the tornado's maximum wind speed was around 200 mph, there was no evidence of building damage from winds at 200 mph or greater, the minimum threshold for an EF5. The ASCE investigators concluded it was impossible to find evidence of E-5 ratings in the damage because none of the buildings met the high construction quality threshold required for determining that level of wind speed, The Joplin Globe reported Saturday.
(Excerpt) Read more at weather.com ...
You would think that based upon the “swath of upheaval” from the tornado scraping the ground—how much topsoil was removed, how deep, for how long? — that one could estimate the strength of the tornado. Surely, our forensics are good enough to tell us that? What about trees in the path? Mature trees versus smaller ones? Oak trees against pine trees?
Those occurrences that you mention are considered in the determination.
Probably because the EF3 & EF4 winds on the outside of the funnel destroyed the buildings before the EF5 winds on the inner portion of the funnel got there.
“The ASCE investigators concluded it was impossible to find evidence of E-5 ratings in the damage because none of the buildings met the high construction quality threshold required for determining that level of wind speed...”
And your mention of trees reminds me of “if there is a sound in the ones with no one to hear it does it make a noise...”
This report sounds more than anything to almost be a slap in the face of Joplin residents, particularly those who lost everything.
They can say whatever they want, but that St. John's hospital wasn't some flimsy structure. Look at it.
In a category F4 tornado, trees are debarked and broken off at the ground. Here we see debarking and trees laying on the ground.
I'm not buying what these A.H.s are selling
This is something that I’ve never understood. What difference does it make if it’s an EF4 or EF5? Better insurance payout? Fed help? What?
Even F5 tornados don’t leave a predictable “swath of destruction”. There are widely variable patterns of damage inside an F5 tornado path ranging from F0 to F5. The worst damage corresponds to the paths of the individual microvortices or “suction spots” that make up the tornado, but even these vary in intensity. The damage criteria reference building materials and (to a much lesser extent) trees and foliage, so if there weren’t any buildings affected in a portion of the tornados path it is very difficult to ascertain the power of the tornado in that stretch. Initial estimates almost always overstate the power of the tornado. Uncertainty comes with the territory, I guess.
Apparently the Parkersburg,Ia tornado was an F%. I do not know if there were existing structures engineered to withstand an F5. Interesting note:All seven fatalities in that tornado were sucked out of the basement where they were taking shelter. Amazing power.
It looks almost as bad as what I saw after hurricane Andrew.
Sounds like in addition to needing to be in a basement, that it’s best to be under a concrete slab too.
Yeah I agree, if you want to see some more photos, click below.
That area of Joplin had a lot of trees. That time of the year they would have been blooming and it would have been difficult to see the homes from the air. Check this out.
And click here to read of a receipt from the Joplin Tire Center that was carried 525 miles away...
Click here to read of a receipt from the Joplin Tire Center that was carried 525 miles away...
Click her for a map. Royal Center, Indiana is about 55 miles South-East of Chicago. It’s about 45 miles south east of Lake Michigan.
"My tornado was bigger than yours."
Helps determine how far away you have to drive to find your tupperware lids.
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