Archive for June, 2013

Tornado Tracks from Moore & El Reno, Oklahoma Show an Eerie Correlation with Heavily Populated Areas

Thursday, June 20th, 2013

Author: Bill Proger, Java Developer, IEM

On May 31, the area around Oklahoma City, already battered by tornadoes a little over a week before, experienced several more tornadoes that caused damage including loss of life.  A tornado reaching an EF-3 (Severe) wind speed and damage rating touched down just southwest of the city of El Reno, approximately 30 miles west of Oklahoma City.  It moved east and ended at the Interstate 40 corridor.  On May 20, a tornado reaching the maximum EF-5 rating devastated a large area immediately south of Oklahoma City. It touched down near the city of Newcastle, cut through Moore, and ended approximately two miles west of Stanley Draper Lake.

The interactive tornado map above, powered by OpenLayers and using an OpenStreetMap layer, shows the May 20 and May 31 approximate tornado tracks, as well as tracks of other tornadoes that have occurred in this area since 1999 and reached a Severe or higher wind speed and damage designation. Their tracks are approximated with straight lines between their starting and ending locations.

It is apparent from the map’s pattern of streets and building footprints at higher zoom levels that many tornadoes produce tracks that impact lives and infrastructure in urbanized, heavily populated areas. As an example, zoom in on the May 20, 2013 track just west of Interstate 35.  Panning west in the storm track’s reverse direction, we see the intersection of the track with Plaza Towers Elementary School, on which the most closely followed rescue effort was focused, and with Briarwood Elementary School a little to the southwest.  Near the school, the track intersects the footprints of other mass gathering places, including a movie theater next to the interstate, and many individual homes.  Looking at the May 31 track, the reader can see its convergence with Interstate 40, a major highway serving Oklahoma City.

As focused as many tornadoes often are in their damage paths, a tornado moving through a heavily populated urban area can have a devastating cumulative effect even with a relatively short track. Current discussions about increasing public safety during tornadoes are very timely.