El Reno-Piedmont Tornado of May 24, 2011

The El Reno-Piedmont tornado of May 24, 2011 - not to be confused with the wider El Reno 2013 event - was a long-track EF5 that traveled 63 miles across central Oklahoma. Peak winds estimated at 210 mph. 9 killed, 181 injured. It was the first Oklahoma tornado rated EF5 (the first Oklahoma F5/EF5 since Bridge Creek-Moore in 1999).

Two Different "El Reno" Tornadoes

Two separate significant tornadoes hit the El Reno, Oklahoma area:

• May 24, 2011 (this event): EF5, 210 mph, 63-mile path, 9 killed
• May 31, 2013: EF3, 296 mph (radar), 2.6 miles wide (widest ever)

Both are famous but for different reasons. The 2011 event was rated EF5 because it hit engineered structures. The 2013 event had higher measured winds but was rated EF3 because it primarily struck open country.

Formation and Path

The May 24, 2011 tornado touched down at approximately 3:50 PM CDT west of Chickasha, Oklahoma. It moved northeast for 63 miles, passing through the north side of El Reno and into Piedmont before dissipating in northern Oklahoma City suburbs.

Damage

• Multiple homes swept from foundations in El Reno and Piedmont
• Debris scoured from ground surfaces
• Foundation-sweeping damage across the tornado's peak intensity
• Vehicles thrown hundreds of yards

Casualties

Nine people died in the tornado:

• Multiple deaths in Canadian County (El Reno area)
• Deaths in Kingfisher County (Piedmont area)
• One death from a wind-driven tree in Oklahoma City suburbs

The Oklahoma EF5 Drought Ended

Before May 24, 2011, Oklahoma had not had an F5 or EF5 tornado since Bridge Creek-Moore on May 3, 1999 - 12 years. The 2011 El Reno-Piedmont event ended that streak. Just two years later, Moore 2013 EF5 would follow.

Warning Response

The NWS Norman office had been issuing continuous severe weather warnings for the region. Local TV coverage tracked the tornado from before touchdown. Warning lead times were substantial - approximately 20 minutes for El Reno and 25+ minutes for Piedmont. Death toll of 9 was low relative to a violent tornado of this scale, largely due to warning effectiveness.

Legacy

The May 24, 2011 event demonstrated that Oklahoma's central corridor remained a violent-tornado hot zone. Combined with the Joplin, MO EF5 just two days earlier and the April 27 Super Outbreak weeks before, May 2011 marked one of the most intense tornado periods in modern US history.