Bob Hartig
EF5
In his chase stats for 2012, fellow chaser Simon Brewer notes that the March 2 Henryville tornado caused "damage to a highway southwest of Henryville peeling and tossing large 6-10 inch thick slabs of asphalt, some weighing around 10,000 lbs, 30-50 meters creating large and deep impact craters." Because of the severity of the damage, Simon has considered the tornado to be an EF5, though it was officially rated an EF4. Since highway scouring is not among the DIs listed on the EF scale's rating system, I understand why the lower rating was assigned; there's no mechanism for assigning a higher rating based on asphalt peeling.
It's too bad, though. I realize that a number of factors can work together to peel asphalt, and EF5 winds aren't necessary to get the job done. But in the Henryville case, what Simon has described sounds pretty wild. And it wasn't the work of a slow-moving tornado nibbling away at small sections of asphalt by abrasion; it was a fast-moving tornado ripping up large chunks in seconds.
I take an interest in this because the tornado crossed that stretch of SR 135 less than a mile in front of me. It took mere seconds to do so--it had to have been moving at 60 mph--and it was rapidly intensifying at the time. Bill Oosterbaan and I got cut off by downed powerlines at Dutch Creek Road, just south of the main damage path, so I didn't see the scoured section of highway. But I believe that Simon did (correct me if I'm wrong, Simon). I was surprised to learn of the scouring, but not too surprised, because it was obvious when the tornado crossed that it was entering the violent category--not large at the time, but very intense and growing rapidly.
I'm curious whether highway scouring was ever discussed as a possible DI during the development of the EF Scale. I can see problems associated with using it as such, but those being granted, still, large chunks of asphalt ripped up by a swiftly-moving tornado that took only ten or fifteen seconds to accomplish such a feat seems like something that should at least be given consideration.
It's too bad, though. I realize that a number of factors can work together to peel asphalt, and EF5 winds aren't necessary to get the job done. But in the Henryville case, what Simon has described sounds pretty wild. And it wasn't the work of a slow-moving tornado nibbling away at small sections of asphalt by abrasion; it was a fast-moving tornado ripping up large chunks in seconds.
I take an interest in this because the tornado crossed that stretch of SR 135 less than a mile in front of me. It took mere seconds to do so--it had to have been moving at 60 mph--and it was rapidly intensifying at the time. Bill Oosterbaan and I got cut off by downed powerlines at Dutch Creek Road, just south of the main damage path, so I didn't see the scoured section of highway. But I believe that Simon did (correct me if I'm wrong, Simon). I was surprised to learn of the scouring, but not too surprised, because it was obvious when the tornado crossed that it was entering the violent category--not large at the time, but very intense and growing rapidly.
I'm curious whether highway scouring was ever discussed as a possible DI during the development of the EF Scale. I can see problems associated with using it as such, but those being granted, still, large chunks of asphalt ripped up by a swiftly-moving tornado that took only ten or fifteen seconds to accomplish such a feat seems like something that should at least be given consideration.
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