"Scientists See Rise in Tornado-Creating Conditions"
"When at least 80 tornadoes rampaged across the United States, from the Midwest to the Gulf of Mexico, last Friday, it was more than is typically observed during the entire month of March, tracking firm AccuWeather.com reported on Monday. According to some climate scientists, such earlier-than-normal outbreaks of tornadoes, which typically peak in the spring, will become the norm as the planet warms."
"'As spring moves up a week or two, tornado season will start in February instead of waiting for April,' said climatologist Kevin Trenberth of the National Center for Atmospheric Research.
Whether climate change will also affect the frequency or severity of tornadoes, however, remains very much an open question, and one that has received surprisingly little study."
"Warm Winter Helped Fuel Tornado Outbreak" (USA TODAY)
"U.S. Tornado Climatology" (National Climatic Data Center/NOAA)
"UPDATE: Tornadoes, Extreme Weather And Climate Change, Revisited" (Climate Progress)