Although a lot of devastating tornadoes have been reported recently, about the same number of twisters have happened during all of the past few decades.
According to a study from the National Oceanic and Atmospheric Administration, tornadoes in America are grouping together to cause more damage.
The devastation that a tornado leaves in its path is immense, and while it appears that many more have occurred recently, the annual number of larger twisters today is almost the same as the 1950's.
What has changed, according to a recent study from the National Oceanic and Atmospheric Administration, is that their overall daily frequency has decreased, but more are forming on the same day.
WESSINGTON SPRINGS - South Dakota Tornados
Tornadoes are hitting in clusters more often
Tornado strikes South Dakota town, razing dozens of homes; 2 hurt http://t.co/17xeZxZlhI | http://t.co/eXgqz5ULmI
WATCH: A #tornado in the middle of nowhere can actually be quite beautiful: http://t.co/HsT6clEpyO #sdwx http://t.co/LsEkifIrn1
Pls keep them in your Dua's, there is said to be a tornado ripping through south Dakota. http://t.co/hPPI9sN8HC
Tornado damage in Wessington Springs, #SouthDakota. State Officials are responding. State EOC is activated. #SDwx http://t.co/1JXXuY0W3s
Wessington Springs, SD Major damage.. everyone accounted for as of right now. http://t.co/ONXCNAAuYx
Wednesday tornados leaves path of destruction in South Dakota http://t.co/dm95NEudo0 http://t.co/xiiqZhbhzO
Photo gallery:Tornado rips through South Dakota town. Thankfully, no deaths / serious injuries http://t.co/ejGoj7KaM0 http://t.co/NETO76Zufs
More #severe #storms in the Central US on Wednesday, including a tornado in South Dakota: http://t.co/iO0bAJ2kh6 http://t.co/wb5Ke3m5or
Tornado in South Dakota rips "through heart of town" (photo: Joe Ahlquist, Argus Leader/AP): http://t.co/f7fiSqMuJX http://t.co/Yd0PEqftps
Watch: a tornado tears through a small town in South Dakota http://t.co/SMVJOiZsYW http://t.co/sYLPRppMaP
DEVELOPING: Everyone is accounted for after tornado rips through a South Dakota town http://t.co/zk78fseDs2 #7News http://t.co/vq9gn8fEB3
WOW! Tornado Wednesday evening near Alpena, South Dakota. Photo: Shalyn Phillips. #Tornado #SDwx http://t.co/CX0a7Zla3k
People reportedly trapped after South Dakota tornado. http://t.co/Vtf3M9JqFV Wire: http://t.co/8VW5igTZ6n http://t.co/OKH59yZxkQ
Rope #tornado near Woonsocket, South Dakota this evening by @DjDerve. http://t.co/hiHCCzh0YQ
Very very bad situation here IN SD http://t.co/KhgnYyTrYr
Multiple tornado warnings in South Dakota right now, confirmed #tornado! http://t.co/jq0X9yO6rw
Still on tornado warned storm in South Dakota. It's trying.. @JWSevereWeather @JimCantore #sdwx http://t.co/tDbI9INOLW
Tornado warned storm in South Dakota north of Belle Fourche. @JWSevereWeather @NWSRapidCity #sdwx http://t.co/DlbOerjdGM
Tornado debris signature evident on radar south of Humboldt (west of Sioux Falls) in South Dakota. http://t.co/DBU1wJ6Cg8
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The researchers excluded the weakest tornadoes, known as EF0, and concentrated on those rated EF1 to EF5 in strength. 1973 for example, saw 187 days of tornadoes, while 2011 only experienced 110 days, but with more than 30 occurring on 9 of those days.
Today, approximately 20 percent of twisters in the U.S. occur on just 3 days of the year. Harold Brooks, a research meteorologist with National Oceanic and Atmospheric Administration's National Severe Storms Laboratory in Norman, Oklahoma is quoted as saying:
"Concentrating tornado damage on fewer days, but increasing the total damage on those days, has implications for people who respond, such as emergency managers and insurance interests."
Experts still aren't sure what is causing the change in tornado behavior, but some speculate that climate change might be playing a role.