ERTH 260: Homework 9, Spring 2017

Lessons from the El Reno May 31, 2013 Tornado Tragedy

100 points

Due Friday 14 April 2017

1.   What are the major factors contributing to danger to meteorologists researching tornadoes in the field, as outlined in the Documentary on the El Reno OK tornado? (40 pts)

    1. Exact tornado trajectory is unpredictable; strategies to collect data based upon average motions of previous tornadoes can put researchers at risk

    2. Tornado diameter can change quickly, with 50 to 150% increase in diameter possible; strategies to collect data by being continually close to a tornado can put researchers at risk if such diameter changes occur

    3. Tornadic winds often exist outward from the observable tornado funnel; researchers who place themselves near the condensation funnel put themselves at risk

    4. Large tornadoes are often associated with multiple satellite tornadoes that move counterclockwise around the parent vortex; researchers who approach large tornadoes risk an encounter with these satellite vortices

    5. Tornadoes associated with the class of thunderstorms called "High Precipitation Supercells" are often difficult to see because they are surrounded by heavy precipitation; researches who attempt to approach the area in which a suspected tornado might occur with such storms often must pass through low visibility associated with heavy rain and hail, only to encounter the tornado suddenly

    6. Manuevering around or away from tornadoes may be thwarted by the population evacuating an area; researchers may be stranded on a road over which a tornado will then pass


2.   The three researchers of the TWISTEX team were killed because of one of the factors outlined in the Documentary. Which? (15 pts)

The Twistex Team was killed when a satellite tornado, called a suction vortex or subvortex, developed over their location and remained stationary for a relatively long period.

3.   List three of these factors that the Reed Timmer group ignored in their activities related to the Wray CO tornado of May 7, 2016 (15 pts)

(a), (b), (c), and possibly (d).   All of these are issues when storm researchers or chasers move within ¼ mile of a small tornado and up to a mile or more from a large tornado.  The other issue for the Timmer group centers on situation awareness and risky behavior in general, emphasized by Reed’s comment “…we’re nearly out of gas….”

4.   List three of these factors that Bruin team ignored in their activities related to the Katie OK tornado of May 9, 2016 (15 pts)

(a), (b), (c), and possibly (d).   All of these are issues when storm researchers or chasers move within ¼ mile of a small tornado and up to a mile or more from a large tornado.

5.   List three ways the tornado observing shown in the Garfield video of the forming Dodge City KS tornado of May 24, 2016 illustrate safe field research behavior. (15 pts)

The Garfield group was a safe distance from the tornado making erratic motion and sudden development of satellite tornadoes or subvortices not an issue for them, as they were apparently several miles away.  Also, the group was not involved in a frantic chase, and was parked safely off the road.

6.   (Extra Credit) (5 pts) In watching the Documentary (in (1) above), and then watching the video (in (4) above), there is irony. What is it?

Mr. Magowan was a contributor to the El Reno Documentary, and was also a member of the Bruin team that engaged in unsafe behavior three years after the Documentary had been produced.