KRMG In-Depth Report: Beginning to write the history of the devastating derecho of June 18th

TULSA — Even as the cleanup from Sunday’s devastating windstorm continues across eastern Oklahoma, the process of documenting what happened, and gauging lessons learned, has begun.

While the National Weather Service does not officially designate storms as derechos, as it does with tornadoes or hurricanes, its website has a definition which essentially involves winds exceeding 58 mph, which sustain over a distance of 240 miles or more.

[Hear our In-Depth Report on the derecho of June 18th HERE]

Further research indicates some debate over how the term should be defined (see the Wikipedia article) but for general purposes, NWS Meteorologist-in-Charge Steve Piltz at the Tulsa office tells KRMG this event, in his opinion, certainly qualifies.

Discussing the storm treks, he said “I roughly measured it out at 356 miles. I just did it quickly, but still, it’s... this actually started as supercell thunderstorms, rotating storms that had tornadoes with them out in the panhandle and southwest Kansas. And as they congealed into a complex, they began to accelerate toward the east and southeast, and so I started my mark basically right at the body of the northwest part of Oklahoma, and that carried on into southwest Missouri.”

He talked about the difficulty of gauging surface wind speeds using radar, and gave credit to the emergency management team in Cushing (Creek County) that managed to get a message to the NWS office just before losing power.

“They, with power failing, they were able to get a quick message out to us, and basically told us that their wind gauge just hit 98 miles per hour,” Piltz said Thursday.

Damage he saw would indicate gusts of more than 100 mph in some parts of the Tulsa metro, Piltz added, though no official anemometers recorded those speeds.

In minutes, the winds left hundreds of thousands of people without power, and as of late Thursday afternoon, the Public Service Company of Oklahoma (PSO) still reported more than 60,000 customers remained without service.