Stanley Changnon, former director of the Illinois Water Survey did a study showing that, although the national media attention was mainly on the feared El Nino, La Nina’s were far more dangerous and costly with more cold and heavy winter snows that paralyze economies and transportation, more spring flooding and deadly-damaging tornado outbreaks, and more land-falling hurricanes than El Nino. The last few years and especially this year is an illustration of this.

This is yet another active La Nina tornado season to go with many others in history.

This type tornado season is also related to sunspot cycles, the water temperatures in the North Pacific (another cycle) , and warmer than normal water in the Gulf of Mexico.

Let me repost this from CLTV Meteorologist Tim McGill:

Northern Illinois University meteorologist Walker Ashley published a study in 2008 that looked into the reason why the death rate from tornadoes was so high in the areas hit hard Wednesday.   Here are some of his conclusions; NOTE tornado sirens are NOT found to be a big factor. Sirens are only designed and intended to warn people who are outdoors away from radio/TV, not for people who are inside buildings:

• Mobile home density. The NIU meteorologist said 44 percent of all fatalities during tornadoes occur in mobile homes, compared to 25 percent in permanent houses. The southeast United States has the highest percentage of mobile-home stock compared with any other region east of the Continental Divide.
• Nighttime tornadoes. The southeast United States has a higher likelihood of killer nighttime tornadoes. Most states within this region have greater percentages of tornado fatalities occurring at night than other states Further, nocturnal tornadoes are more difficult to spot, and people are more likely to be asleep when warnings are issued.
• Forested areas. Whereas regions within the Great Plains by definition are lacking in tree cover, the mid-South region is more forested, leading to reduced visibility both for the public and spotters.
• Early season storms. Storms that occur before the national peak in the severe storm season, which spans May and June, may catch people off guard during a tornado event.
• Complacency. In contrast to other parts of the country, the South lacks a focused "tornado season," which can lead to complacency. "In the South, people think tornado alley is where you get tornadoes," Ashley said. "That sort of perception also leads to complacency, which in turn leads to higher fatality rates." He points out that Oklahoma is known worldwide for the frequency of its tornadoes. Yet the state has fewer fatalities than Arkansas, Alabama and Mississi

Studies also indicate storms in the south often move much faster than in the Great Plains and the probability of detection is lower (see previous blog posts).

So the odds are stacked against those of us who live in the South and Southeast states ("Dixie Alley") compared to "traditional tornado alley".