The 2013 El Reno tornado was a long lived, violent event that occurred during the evening of May 31, 2013 over central Oklahoma. The tornado was most notable for its impressive size, which was measured at 2.6 miles wide, the largest on record since observations reliably began in 1950. In addition to this, 8 people lost their lives, including Tim and Paul Samaras, and Carl young, all professional storm chasers who were killed deploying probes before being caught off guard by the sudden intensification, widening and change of direction as they did so. The tornado is a subject of immense debate amongst meteorologists, who officially rated the tornado as EF3 based on damage, before upgrading it to EF5 after finding a 295 mph wind on Samaras's radar. In the end, it was downgraded back to EF3, as the radar data was deemed invalid, as no EF5 damage occurred during this time frame.
The supercell that spawned the 2013 El Reno tornado began life as part of a quasi-linear convective system, or a line of storms, which proceeded to rapidly become severe. The cell that spawned the tornado in question was first severe warned at 1733 CDT, and by around 1750 CDT, it became tornado warned after numerous spotters reported a large,rapidly rotating wall cloud in association with the storm, which eventually touched down at 1803 CDT as several multiple vortex tornadoes.