2013 a tranquil year for tornadoes so far

Doyle Rice | USA TODAY

Hurricanes have been on holiday this year, and so too have their ferocious cousins, tornadoes.

The USA is enjoying its second-consecutive below-average tornado season, and one of the calmest years for tornadoes in more than two decades, according to data from the Storm Prediction Center in Norman, Okla.

"It's been a near-record quiet year, especially with respect to strong to violent tornadoes," said warning coordination meteorologist Greg Carbin of the prediction center.

Except for a stormy stretch in late May, which included a deadly EF5 tornado that devastated parts of suburban Oklahoma City, killing 24 people, the year overall has been remarkably quiet.

So far this year, through the end of October, there have been about 800 reports of tornadoes, Carbin said. In a typical full year, based on data from 1993 to 2012, the USA has more than 1,250 twisters. November and December tend to be slow months for tornadoes, so it's unlikely the yearly total will come anywhere close to that number.

Since 1990, the only other year that was quieter than this year was 2002, when only 741 tornadoes were reported from January-October.

The year of 2012 was also a below-average season, as only 878 tornadoes had formed by this point in the year. Combined with the 2013 season, it's the quietest two-year period since the late 1980s.

Is this part of a trend? No, said Carbin, who said that each of the past two years had very different reasons for the lack of tornadoes. Simply put, spring 2012 was too hot, and spring 2013 was too cold.

Last year was hot and dry, and "drought conditions don't go hand and hand with severe weather," Carbin reported. This year, the unusually chilly spring across much of the country prevented the contrast in temperatures that is usually needed to spawn severe storms and tornadoes.

Also, the lack of landfalling tropical storms and hurricanes — which can spawn tornadoes — has also been a factor, according to Carbin.

The two quiet years come on the heels of the deadly and destructive 2011 tornado season, when more than 1,600 tornadoes killed 553 people and did more than $27 billion in property damages.

So far, 45 Americans have died due to tornadoes this year, according to SPC data. Forty-two of those killed were in May. The most recent was on June 24. "This is a relatively long stretch," Carbin said.

On average, tornadoes kill about 60 Americans each year.

Tornadoes typically affect the U.S. more than any other nation. Each year, "the U.S. experiences about 80% to 90% of all of the tornadoes that occur across the world," says Randy Cerveny, an Arizona State University geographer.

Carbin said the quiet years are welcome, but he puts them in perspective: "It really only takes one bad day; it doesn't matter if the year is above or below normal. Tornadoes can destroy people's lives."