We're now well past the time of year when tornadoes are a big worry, and overall it's been a very quiet year in the U.S. for twisters. Around 600 tornadoes had been reported across the country as of the end of September, compared to an average of more than 1000 by the same time over the last three years.

Tornado season started off slowly thanks to a cold air outbreak in February and March that delayed the start of the season in the southeastern U.S. Only 32 tornadoes were reported in those months, compared to an average of close to 100. Tornado activity picked up in April and May, but then in the June through August period, less than half the average number of tornadoes was observed.

Of course, fewer tornadoes generally mean fewer tornado-related casualties, and that's certainly been the case this year with just eleven tornado fatalities nationwide. Surprisingly, the most destructive and deadly tornado so far was not in Tornado Alley, but rather in the East, in Maryland, back on April 28.