Everyone has probably heard about the tornado in western Iowa (north-northeast of Omaha) that killed 4 Boy Scouts and injured around 40 others at a campground in a wooded hilly area. It was a national news item last Thursday and Friday, and a very sad story. But the story is also an encouraging one in that, after looking into the details, the Boy Scouts and their supervisors reacted well to the timely NWS warning via weather radio, and did everything they could, given that there was no concrete shelter or below-ground shelter at the campground. I did an informal damage survey of the tornado on Thursday 6/12/08, which is shown above.
Shawna Helt and I were storm chasing on 6/11/08, and intercepted the same supercell that produced the tornado, about a half hour later between the towns of Charter Oak and Dunlap, Iowa (see video grab and radar images above). We had to work hard to stay out of the way of 5 different mesocyclones as we dropped southeastward from the Sioux City area toward Harlan, Iowa in hilly, difficult viewing terrain on a zig-zaggy road network. Each circulation was rain-wrapped (see the video grab above) and, though we were tempted to penetrate one or two of the hidden rotation areas, we knew that would be too dangerous. After later finding out about the unfortunate tornado event at the campground (we didn't know about it while chasing), we are very glad that we did not drive into any of the rain-wrapped areas, and stayed out of the way of these dangerous circulations.
Storm chaser Kelly Martinson and another chaser had a close encounter a few minutes earlier with the tail end of the Little Sioux campground tornado as it was dissipating southwest of Moorhead, Iowa. His video was televised nationally, and he has had some criticism regarding being so close. I think the lack of visibility (HP storms and rain-wrapped circulations), the outage of Omaha radar toward the end of the Little Sioux tornado, and a frustrating hard-to-navigate road network all contributed to their driving into the edge of the tornado circulation. Having been in the same area on the same storm, Shawna and I can understand how that situation might have happened, and are just happy that Kelly and his chasing companion did not get injured. At any rate, the video is about the best example I can think of to show how dangerous rain-wrapped tornadoes are. The tornado was simply not visible until it was right on top of these storm chasers.
Shawna and I talked to one of the Boy Scouts who survived the tornado last Thursday. The tornado warning was issued 10 minutes before the tornado hit the campground. The Boy Scouts had gone through a tornado drill the previous Monday, and were prepared. They and the camp supervisors went to their designated places. Unfortunately, with no true shelter provided at the campground, bunk houses served as the only places to take cover. One of the Scouts timed the tornado passage at between 7 and 8 seconds, and told us the building "exploded" and lifted away, toppling a chimney onto the boys along with other debris. We were most impressed with stories of how the Scouts stayed calm after the event, giving first response treatment to those injured and handling the situation in a truly admirable way. If there is any lesson to come out of this event, it is that all campgrounds and similar outdoor facilities should have a concrete or underground shelter on the premises, as that is what would have saved lives in this case.
Jon Davies - 6/15/08
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