Meteorologists awed by extremely rare type of tornado and weird radar sights

Radarscope

Powerful storms roared across parts of southern Oklahoma Tuesday night and produced dangerous and unusual tornadoes, including one incredibly rare type.

Multiple tornadoes were ongoing simultaneously in Tillman County, Oklahoma, when the weather got weird.

At least two of the tornadoes exhibited very odd behavior: one powerful tornado looped backward and recrossed its previous path and another significant tornado spun in the “wrong” direction.

“You certainly don’t see this every day,” Rick Smith, a meteorologist with the National Weather Service in Norman, Oklahoma, told CNN.

Even stranger, the tornadoes appear to have emerged from the same powerful thunderstorm.

Here’s how it played out.

A wild night in Oklahoma

A supercell thunderstorm – a powerful type of storm responsible for most severe weather – roared to life near the Oklahoma-Texas border and tracked east. This storm produced a “large and extremely dangerous” tornado north of Loveland, Oklahoma, just before 10 p.m. CDT, according to a weather service warning.

Radar imagery shows the tornado tracking east before slowing down considerably, taking a turn to the north, then to the west, and looping over where it had just hit.

Storms generally move from west to east, but powerful tornadoes can sometimes curve back to the west as they lose strength, according to Smith. What’s much more uncommon in this situation is that the tornado completed a full loop back over its own path.

An EF5 tornado that decimated the town of Greensburg, Kansas, in May 2007 is perhaps the most devastating example of a looping track. The tornado demolished the town and then looped back just north of the worst damage.

Tuesday night’s spiraling tornado weakened as it completed its pirouette near Loveland, but a new issue then emerged: a new, powerful anticyclonic tornado spun up on the southern edge of the same storm. It’s likely these two tornadoes were briefly active at the same time, Smith said.

Tornadoes in the Northern Hemisphere typically spin cyclonically, or counter-clockwise, but this new tornado was spinning clockwise, or anti-cyclonically. Only about 1% of tornadoes are estimated to be anticyclonic, according to the weather service.

Tuesday night’s anticyclonic tornado was one for the history books on several fronts.

Just before 10:30 p.m. CDT the “large and extremely dangerous” anticyclonic tornado formed southeast of Loveland where it was briefly “nearly stationary or moving very slowly south,” according to weather service warnings.

“It’s not common to see (tornadoes) be nearly stationary,” Smith explained. “Tornadoes are almost always going to just go wherever the supercell thunderstorm goes.”

But select storms on Tuesday night were barely moving and created an environment where it was possible for a tornado to develop, loiter, then redevelop, according to Smith.

Not only was this tornado churning in the “wrong” direction while hardly moving forward, it also produced tell-tale damage signatures on radar imagery that meant it lifted debris thousands of feet into the air, a sign of a strong tornado. Most anticyclonic tornadoes are weak and short-lived, meaning this twister was rare on two fronts.

Luckily, the erratic twisters unfolded over a sparsely populated area and there are no reports of injuries, deaths or significant structural damage, the Tillman County Emergency Management office said Wednesday afternoon.

Additional severe thunderstorms are possible from Texas to Nebraska Wednesday. Some of these storms may produce tornadoes, including in the same areas of southwestern Oklahoma hit by Tuesday night’s storms.

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