National Severe Storms Laboratory

Crowd-Sourcing the El Reno (2013) Tornado:
Making Storm Chaser Observations Scientific

Anton Seimon, Appalachian State University
John T. Allen, IRI-Columbia University
Skip J. Talbot, Springfield IL

11 December 2014, 3:00 PM

National Weather Center, Room 1313
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK

The El Reno supercell of 31st May 2013 produced the largest observed tornado, with internal sub-vortices featuring the second-strongest wind speeds ever documented. Throughout its life cycle, the tornado was observed in detail by multiple remote-sensing platforms, including mobile research and operational radars and lightning detection networks. As a synoptically-evident event, occurring at the climatological peak of the tornado season, the El Reno storm was captured in high-resolution imagery and video footage by a multitude of storm chasers. Post-storm surveys also documented the tornado track and associated damage in fine detail. The tornado’s exceptional magnitude and the wealth of observational data obtained make the El Reno storm particularly compelling for scientific investigation.

To collate the available imagery and video footage, our research team conducted the El Reno Survey ( This project was designed to crowd-source storm chaser data and compile submitted materials in a quality controlled, open-access research database. Internet searches identified at least 250 chase teams that observed the El Reno Storm. Solicitations to the storm chaser community, extended via various social media outlets, have yielded 82 registered participants to date, all contributing imagery and other data resources to the project database. The database is likely the largest archive of visual material compiled for a single tornado. After further compilation, this database will become accessible to the scientific community and other interested users through a simple registration process.

This presentation will detail how uncontrolled storm chaser imagery can be precisely fixed in time and space to make it usable for research applications. We will demonstrate novel visualization tools combining video and radar with user-selected geographic referencing. Collation of synchronous multi-perspective imagery will also enable the generation of some first-ever three-dimensional products from visual storm observations, such as mapping of extremely intense, rapidly propagating sub-vortices and 3D animations of important phases of the tornado's evolution. The approach employed by our study is presented as a new model for post-storm data collection, with templates and instructional materials being created to facilitate replication by interested parties for both past and future tornadic storms of special research interest.

For accommodations based on disability, or more details, please contact Roger Edwards ( All visitors without NOAA or University of Oklahoma identification must register at the registration desk on arrival. Visitor parking is available for all University visitors. However, faculty/staff/students must have a current multi-purpose parking permit. Additional parking is available at the Lloyd Noble Center (LNC) for those individuals who do not have a parking permit. You do not need a permit to park in one of 1,200 spaces reserved for CART bus riders, although you must ride the CART shuttle to park in the reserved area. This area is on the north central side of the Lloyd Noble Center. Elsewhere at the LNC, permits are required.