TULSA — A violent storm system packing up to 80 mph winds and lightning that churned through the Tulsa area early Wednesday was later classified by meteorologists as a rare derecho because of the widespread wind damage it left throughout the city.
Meanwhile, nearly 70,000 homes and businesses in Tulsa County were still without electricity Wednesday afternoon — there were more than 100,000 at the storm’s peak — and utility officials said it could be several days until all power is restored.
Authorities said one firefighter was injured while operating a chain saw to clean up debris, but the injuries weren’t life-threatening. No other injuries were reported.
Late Tuesday, Gov. Mary Fallin declared a state of emergency for Tulsa County and 34 more counties due to the overnight storms, damaging winds and flooding.
Her executive order paves the way for state agencies to make emergency purchases and is a first step in seeking federal assistance if necessary.
National Weather Service meteorologist Karen Hatfield said derechos are a special type of damaging storm event that have consistent reports of wind damage or measured wind gusts of 58 mph or over for at least 250 miles.
Hatfield said forecasters at the weather service only informally discussed the possibility of the weather event but did not use the term in forecasts, instead opting to use layman’s terms language predicting a severe and damaging wind event.
Adding to the difficulty of classifying a possible derecho ahead of time, the classification typically comes after extensive field work to survey the wind damage to estimate how widespread it was, she said.
“They are not common,” she said in an interview. “Typically across the country, there are only a handful of derechos every year.”
The storm snapped power lines and decades-old trees and left tens of thousands of homes and businesses without electricity.