"Right now we've been getting a few thunderstorms, but they're very severe supercell thunderstorms, " said Michael Scotten, a meteorologist with the National Weather Services.
And in the most extreme cases, a violent tornado is born beneath that spinning white cloud of updraft that meteorologists call the supercell thunderstorm.
One of the hit-makers in the mobile-game industry once again hails from Finland, but Supercell is making money with cows and dragons instead of Angry Birds.
During the past 20 years, supercell thunderstorms have been the focus of intense academic and government research to understand how they work and how they produce tornadoes.
In Oklahoma, storm chasers with cameras in their cars transmitted video showing a number of funnels dropping from the supercell thunderstorm as it passed south of El Reno and into Oklahoma City just south of downtown.