It is no secret that weather is getting more and more extreme. What was once considered "normal" weather is no longer. New York City now has its own tornado season, and tornado months in the South, and Southeast are no longer relegated to spring and fall but instead begin as early as January.
Tornado season typically occurs in the fall and spring, when the hot and cold seasons battle for power resulting in a weather clash ... and tornadoes. This year, that clash of climates seems to be taking place in January. According to a report from the National Oceanic and Atmospheric Administration, the number of "preliminary" tornadoes reported in January 2012 (95) was e well above the normal number reported on average from 1991-2010 (35). This makes January 2012 the January with the second most reported tornadoes on record, the first is 1999 which had over 100.
January tornadoes are certainly not unheard of, but the rate at which they've been steadily increasing speaks to the changing climate and weather patterns.
The severity of tornadoes has also been notable as of late. Most memorably were the damaging storms in 2011 in Joplin and Tuscaloosa. The Joplin tornado, which struck in late May, was the deadliest since 1947, 161 people were killed. The Tuscaloosa tornado (which also largely affected Birmingham), was part of an outbreak of tornadoes from April 25-28 during which 358 tornadoes touched down. It was the largest tornado outbreak in U.S. history.
What these changes mean for the environment, and for years to come remains to be seen. But it is undeniable at this point that warmer weather is changing the way tornadoes affect the U.S.