Saturday, June 1, 2013

Comments About Friday's Storms

By popular demand, here are my comments about two aspects of Friday's Oklahoma storms.

Driving Away From a Tornado

In certain, rare, situations this can be a viable strategy. Note I said, "rare." Those would include:

  • Living in a mobile home in an area without a shelter.
  • Living in a travel trailer or RV with no shelter.
  • You are willing to drive away when a "particularly dangerous situation watch (PDS)" (when the sky may be clear) is first issued well before storms form.
  • You have a place to stay in a "safe" area (defined below).
Generally, the safe area would be past the western boundary of the watch. In the case of yesterday's particularly dangerous situation watch in Oklahoma, for a Tulsa resident, that would mean driving more than 100 miles. 
Unless it is a PDS tornado watch, I would not move even if I lived in a mobile home. 

Once a warning is issued it is too late to drive away. That is why you need a plan. Don't have one? Now is the time!

The Stupid Behavior of Some Storm Chasers

Thursday, I defended storm chasers after what I thought was silly criticism in the wake of the Wichita-area tornadoes of May 19. I stand by those remarks especially since I mentioned (see comments) that the chasers related to the media were often the worst.  As far as I know, all the chasers that got into trouble yesterday were affiliated with media companies or under contract with them. 

I am unaware of any research chasers getting into trouble or storm chase tours having difficulty. 

What happened? In the simplified diagram below, the tornado (smaller black circle) was embedded 
within the larger mesocyclone (wider circle) that was moving east (black arrows). The tornado rotated around the mesocyclone (purple arrows) producing a sinusoidal pattern (example below).
This movement is clear when one time-lapses the velocity data. 

Smaller tornadoes don't behave that way and I suspect the chasers hadn't fully figured out the risks.

I assure you there is a lot of soul-searching in the chaser world today, as it should be.

Addition: Sunday morning... One meteorologist is critical of this posting because I tried to simplify the explanation by using the more familiar word "sinusoidal" (as in sine wave) than a word familiar primarily to meteorologists,"cycloidal." Below, from Wikipedia, is the more technically correct illustration.
There is an excellent animated illustration at Wikipedia.

ADDITION 2PM MONDAY: While not as good as an animation of the velocity data, you can see the cycloidal pattern in the hook echo in this animation


  1. Mike, Brandon Sullivan is listed on NWSChat as a member of the research community.

  2. I was online watching Gary England (sp?)with News9 in Oklahoma City yesterday during this storm. He was telling his chase team to get out of the area, almost arguing with them, saying they did not realize what was taking place, due to what he was seeing on radar.

  3. @Scott: According to his Twitter bio, Brandon is a "meteorology student" and "photographer." I am aware of what research he might be doing. Can you fill me in?

    1. I do not know what research his is doing.I just remember seeing his NWSChat handle as research-brandon.sullivan

      It's certainly possible I am not remembering correctly.

  4. lists Brandon as "Brandon is currently working as an intern at the Storm Prediction Center and is also a student volunteer at the National Weather Service Forecast Office in Norman, OK. He is also employed by CIMMS (Cooperative Institute for Mesoscale Meteorological Studies) where he works with the ARM (Atmospheric Radiation Measurement) program, studying and interpreting data from various instruments across the world."

  5. Mike: I'm seeing this as I wake up today:
    If true...oh, wow

    Tim Samaras, his son, and Carl Young reported dead in El Reno tornado.,d.aWM

  6. It's a sad day in the weather world.

  7. Thanks for sharing your thoughts, Mike. From all accounts I have read online, Tim, Paul and Carl were very safety-conscious and NOT "extreme" chasers, which makes their loss even harder to understand or accept.

    Also, from other discussions I've been following, it appears that several things went wrong with the media reaction to the tornado threat, with the LE reaction to it (closing roads), and with the public reaction to it, that could have made Friday's tornadoes a disaster comparable to or worse than Joplin in terms of fatalities.

    As far as I can tell, the NWS itself (in Norman) performed well. They sent out tweets and posted info earlier in the day telling people that if they didn't feel safe where they were they should leave well BEFORE any warnings were issued; once a warning goes out it is too late to flee.

    Some of what went wrong is, I suspect, part of an ongoing overreaction to Moore, Joplin and other past disasters -- particularly the notion that it is "impossible" to survive a violent tornado above ground, which prompts people without basements or underground shelters to try to flee by car.



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