Thursday, February 23, 2012

Why Meteorologists are Struggling With Tornadoes

When tornado warnings were created in the 1950's, for all we meteorologists knew, there was one type of tornado. Now, we know there are at least five. In order, with the worst on top, here they are

  • Supercell

  • Squall line (aka, QLCS)

  • Tropical storm-related

  • Landspout

  • Gustnado

All of these are (relatively) narrow vertical columns of wind so they meet the definition of "tornado." 

But, we know -- to 100% certainty -- that a gustnado lasts tens of seconds, is difficult for meteorologists to detect, and that it will never do anything like Joplin-style damage. 

So, the National Weather Service is attempting to address this with the experiment I wrote about last week that will conducted, starting April 1, at their St. Louis, Kansas City, Springfield (MO), Topeka, and Wichita offices. They create three-tiered tornado warnings and allow those offices to add "a tornado is possible" to severe thunderstorm warnings. As I comment in the posting, I believe this experiment is misguided.

That said, there is a problem here illustrated by the situation in Kansas Tuesday. 

The radar image below indicate two areas of swirling air (arrows). there were a number of these late Tuesday afternoon.

[caption id="attachment_7330" align="aligncenter" width="337" caption="Radar at 3:39pm Tuesday. Arrows indicate swirling air in the storms."][/caption]

The photo below was passed around on Facebook a number of times and I'm not sure who the photographer was (email me if it is you and I'll happily credit you). It shows a funnel cloud that, I believe, was taken over northern Kansas with one of these swirls. 

As far as I know this funnel never touched down nor did any of the other swirls. Yet, you can clearly see a funnel and -- sometimes -- these do touch down and cause minor damage. Serious injuries are very rare -- the percent of tornado fatalities attributed to these types of tornadoes is well less than 1%.

If it touches down, the eyewitnesses will say, accurately, "there was a tornado!" and will expect a warning. 

So, what do we do? Sound the sirens? Interrupt the TV programs and radio?

While I believe there are better ways to accomplish this than multi-tiered warnings, there is a genuine problem the NWS is attempting to address.

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