El Reno tornado an EF-5 that’s widest in U.S. history

The tornado that touched down near El Reno, Okla., last Friday and killed at least 7 people has been upgraded to an EF-5, with winds near the surface of 296 miles an hour, the National Weather Service in Norman announced Tuesday.

At 2.6 miles wide, it becomes the widest tornado on record in U.S. history, said Rick Smith, warning coordination meteorologist for the Norman branch of the weather service. That eclipses the 2.5 mile-wide tornado that hit Hallam, Neb., on May 22, 2004.

“This is mind-boggling stuff,” Smith said of the preliminary data collected by storm survey teams and mobile radars.

The tornado was on the ground for more than 16 miles on a track that generally traveled east, then southeast, then sharply northeast before ending its 40-minute journey by lifting at 6:43 p.m.

The El Reno tornado had several smaller internal vortices within the main circulation, Smith said, and they were racing along at up to 185 miles an hour. These miniature tornadoes did not hit any structures, he said.

If they had, he added, “any house would have been completely swept clean on the foundation.”

Storm chasers Tim and Paul Samaras and Carl Young were among those killed by the tornado. While Smith declined to address their circumstances specifically, he said “you can imagine how people could get in trouble.

“This would be a very dangerous situation if you were not well aware of your surroundings,” he added.

A tornado that’s 2.5 miles wide “would not look like a tornado to a lot of people.”

This was an exceptionally dangerous storm to be anywhere close to,” he added.

It’s not yet clear whether the El Reno tornado will go down as the strongest tornado on record, Smith said. The Moore tornado of May 3, 1999, had documented winds of more than 300 miles an hour.

“We are so fortunate that this did not impact a densely populated area,” Smith said of the El Reno tornado. If it had, “it would have been catastrophic.”