– 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.