What Should Meteorologists Do?
I had not even gotten home from watching last night's storm when the first critical email about the tornado warning in Sedgwick County hit my inbox. I'd like to spend a moment on the subject of the meteorologist's dilemma in these situations.
Yes, it was a "false alarm." A tornado never made it to the ground.
The storm was a "right mover" (tornado indicator), had a hook echo (tornado indicator, image below) and had rotation as measured by Doppler radar (tornado indicator). To the naked eye, there was lots of organized, sustained rotation.
Yet, for reasons meteorologists do not understand, the funnel cloud never made it to the ground. That is good -- no tornado damage and no one injured. But, it left people grumping about having to interrupt their activities because of the warning.
In a 2003 paper (available here) I differentiate between "unavoidable" and "unnecessary" false alarms. The former is caused when Mother Nature throws us a curve ball. The latter is when meteorologists know a given area is not threatened but limitations in the warning system cause non-threatened areas to be warned. Last night was some of each.
Take a look at the red polygon which is the National Weather Service's path-based tornado warning. The hook (funnel cloud) location is within the polygon. The area inside the polygon experienced an "unavoidable" (from my point of view) false alarm because the science of meteorology cannot determine why this situation was not a genuine danger. So, to be safe, we warn.
But, look the radar image again and you see a dot and the word, "Wichita." That is downtown Wichita where the annual Wichita River Festival was in progress. Because Sedgwick County sounds the sirens countywide, the River Festival and its patrons were subjected to an unnecessary false alarm due to the structure of the county's siren network. It is "all or nothing." That put River Festival officials in a no-win situation. They made the right decision (in my opinion) to shelter.
Fortunately, Sedgwick Co. is in the process of changing the configuration of its siren network so that by tornado season 2012 the sirens will only go off in the path of the storm.
The initial tornado warnings last night were absolutely justified given the imperfect state-of-the-art. I'm sure there are plenty of residents of Joplin, Tuscaloosa, Birmingham, Minneapolis, Raleigh, St. Louis, etc., that wish their tornado warnings this year had been false alarms. This is life-and-death business.
That said, I'm empathetic to the people who took shelter for what seems like no good reason. I'm hopeful we will achieve some breakthrough in the science that will allow us to cut down on the unavoidable false alarms.
If you wait for the funnel cloud to touch down and actually do damage, you've failed to warn whoever it touched down upon. That can't be the standard, and anyone who thinks it should be needs an attitude adjustment.
ReplyDeleteI'll whip out the Russian Roulette argument again: Suppose that only 1/6 of all storms that meet the criteria you describe actually produce a tornado on the ground, and the other 5/6 turn out to be "false alarms". Do you want to play with your life at those odds? Of course you don't.
But I don't even consider this to be a false alarm" for the people in the polygon, any more than it's a false alarm to tell someone not to point an "unloaded" gun at their head. (Ask Terry Kath about that. Oh, you can't, because he's DEAD.) The danger existed even though that storm didn't happen to reach the ground.
I'm amazed at how quick to complain people are. I think issuing the warning Thursday was the right thing to do.
ReplyDeleteI remember the warnings of the 60s and 70s, therefore I'm grateful for the vast improvements that have been made in the warning systems. Even though a tornado did not touch down, I was sure glad me and my animals were indoors when the high winds, hail and flooding rains arrived.
The hook echo, the sighted funnel cloud and the right-moving, southern-heading nature of the complex were enough to sound the alarms and send folks -- including at the River Festival -- inside to safety. Period. If they didn't like it, I wouldn't want to read their kin's complaints if they weren't sent to safety and later perished.
ReplyDeleteI do differ with Mike on one detail I read, or at least I think I read, in his post.
Specifically, even after the 2012 enhancement in the warning-siren system, I believe the sirens would have gone off in the area of the River Festival in this situation. Here's why: I was following the issuance of warnings last night. While at first they did not include the downtown area but did include areas farther north, at least one later warning, when plotted on maps I was viewing, clearly did include the heart of the city. So even with a siren system that was able to "discriminate," there would have been sounding downtown. Correct?
Keith,
ReplyDeleteYes, there would have later been a warning downtown but it would have been more than an hour after the initial warning. The events would not have had to have been shut down so soon.
There were five tornado warnings. I'm not completely sure the last two tornado warnings were absolutely necessary. However, I empathize with the NWS in that people were calling in funnel (and, in a couple of cases) tornado reports all over the place by that time. THEY were in the no-win situation at that point.
As a layperson, I have no business being blase about a tornadic storm. I also have no business getting irritated about a tornado warning being issued for same. I have no business being unprepared to go to shelter in tornadic weather, including the interruption of my personal or commercial business. People who complain about a false alarm better realize that a false positive is better than a false negative. If that is not acceptable to some, then they should invent a better system.
ReplyDeleteIf the storm around the Garden Plain and Goddard area didn't form (see radar image above), sucking the juice out of the tornadic cell, Wichita would have taken a punch that nobody wants to get hit with.
ReplyDelete