– Deadly El Reno, Okla. tornado was widest ever measured on Earth, had nearly 300 mph winds (Washington Post, June 4, 2013):
The tornado that killed 18 people, including 4 storm chasers, west of Oklahoma City Friday was wider than any tornado ever observed or surveyed according to the National Weather Service and leading tornado researcher, Howard Bluestein. The massive El Reno, Okla. twister reached an unthinkable maximum width of 2.6 miles.
“This is the biggest ever,” Bluestein said.
— NWS Norman (@NWSNorman) June 4, 2013
The previous widest tornado record was the F4-rated (on the 0-5 scale) Wilber – Hallam, Nebraska twister that touched down on May 22, 2004. It had a maximum width of 2.5 miles.
The El Reno tornado, originally rated an EF-3 (on the 0-5 Enhanced Fujita scale), was also upgraded to an EF-5, the most intense class of twisters. The upgrade arose not due to the funnel’s width, but because of astonishing wind speed information sensed from several mobile doppler radar units that were in the field, staffed by research meteorologists.
Bluestein, a University of Oklahoma professor, said two of his graduate students clocked wind speeds as high as 296 mph on their mobile doppler unit while observing the storm from the east.
— Angela Fritz (@WunderAngela) June 4, 2013
That 296 mph gust came close to matching the highest wind speed ever measured on Earth. Joshua Wurman, another leading tornado researcher who runs the Center for Severe Weather Research, and his team clocked 301 mph winds in a tornado that struck near Moore, Okla on May 3 1999.
It turns out Wurman and his team were also in the field (in a different location from Bluestein’s team) measuring winds from the El Reno storm and clocked speeds of 246-258 mph using two of their mobile doppler radars, known as Doppler on Wheels.
On the EF-scale, storms earn a rating of 5 if damage surveys suggest winds reached at least 200 mph. Recently, some tornadoes that were preliminarily rated at lower EF levels based on damage have been revised after evaluating doppler radar measurements from field observers.
“In fact, NWS, my grad student and I conferred [to arrive at the EF upgrade],” Bluestein said.
Bluestein added that data from his team’s doppler radar also helped confirm the unprecedented width of the El Reno storm.
“[Our data show] the width of high winds show was over 2 miles,” he said. “It’s remarkable.”
UPDATE, 2:10 p.m.: The Weather Channel’s Greg Forbes provides some additional, incredible detail about the tornado’s winds on his Facebook page:
Fastest winds were in the multiple suction vortices revolving about the parent tornado. They were traveling about 185 mph as they were steered along within the parent tornado winds and had winds about their own axis of about 100 mph that added to the parent tornado’s winds.
Another chaser death identified
The deaths of pioneering storm chaser Tim Samaras, his son, Paul Samaras, and chase partner Carl Young were widely reported Sunday and Monday. Samaras was considered a professional, with over 30 years of chasing experience and led a legitimate research operation.
The Daily Oklahoman now reports a 4th chaser perished in the El Reno storm: Richard Charles Henderson, an amateur chaser. It writes:
From his pickup, amateur storm chaser Richard Charles Henderson took a cellphone photo of the first tornado Friday and excitedly sent it to a friend.
Minutes later, that tornado would kill him.