Record-breaking tornado had rare ‘backwards’ companion

Already breaking records as the widest tornado ever seen, the twister that passed near El Reno, Oklahoma last Friday is making an even bigger name for itself, thanks to a rare companion that was spinning in the 'wrong' direction.

Tornadoes in the United States usually spin around in a counter-clockwise direction, or 'cyclonically'. The large-scale weather system — with its warm and cold fronts, that can stretch from Ontario to Texas — spins in that direction (due to the rotation of the Earth), and that spin direction carries down to the individual thunderstorms the weather system produces, and thus the tornadoes that are spawned from the thunderstorms.

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However, in some cases, when a really powerful tornado spins up, like the nearly 5-km-wide behemoth that swept past El Reno, it can set up powerful 'whirls' or 'eddies' in the nearby flow of the wind and storms around it, that spin clockwise (or 'anti-cyclonically') instead. If these eddies are strong enough, they can develop into tornadoes of their own, which is what happened on Friday.

According to the Washington Post 'Capital Weather Gang', a team of storm chasers, led by Joshua Wurman, a tornado researcher with the Center for Severe Weather Research, was tracking the EF-5 tornado on Friday, when their portable radar picked up another, smaller tornado to the southeast.

"At that point we bailed east towards Oklahoma City," Wurman said. "I’m very happy my team had a radar out there. We only knew about [the anticyclonic tornado] because of the radar; otherwise we may have driven into it."

Apparently no video footage of the tornado was captured, but as noted by the Capital Weather Gang post, this isn't the first time that the El Reno area has seen an anticyclonic tornado, as one hit the local airport back in April of 2006.

You can see a great example of this kind of twister in footage from June 7th of last year, near Calhan, Colorado:

Skip to around 1:30 in the video and you can get a clear view of the clouds swirling into the tornado vortex in a clockwise direction.

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These kinds of events show the extremely cool variety that our weather can produce. It's great to watch them, but at the same time, we can't ever forget how incredibly dangerous these storms are, and we can't forget to thank the men and women who put their lives on the line every day to help keep the rest of us safe.

(Photo courtesy: Richard Rowe/Reuters)

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