Editor's note: this story was updated at 10:06 a.m. to reflect updates to the death toll.
2011 has a grim new place in the record books: the deadliest year for tornadoes in more than five decades, with 482 people killed by the storms as of this writing.
It's the highest number of fatalities from tornadoes since 1953, when twisters killed 519 people, according to the National Oceanic and Atmospheric Administration (NOAA), the home agency of the National Weather Service. [Related: Why Tornado Forecasting is Tough]
As of Tuesday morning, the death toll from the devastating tornado that smashed through Joplin, Mo. on Sunday (May 22) had risen to 117, and could continue to rise as officials sort through the wreckage of the town, home to almost 50,000 people.
The Joplin tornado is also the deadliest single tornado to hit the United States since 1953, when a twister killed 116 people in Flint, Michigan.
In contrast to this year's horrific new record, in 2010 tornadoes killed 45 people in the United States, and 21 people in 2009.
The average annual death toll from tornadoes has dropped steadily since 1925, according to NOAA, most likely due to improved forecasting and better warning systems, but the numbers appear to have leveled off in the last decade.
Sunday's tornado in Joplin, estimated to have been three-quarters-of-a-mile across and packing winds of up to 198 mph (318 kph), intensified remarkably quickly, according to weather trackers, morphing from a mere funnel cloud into a monstrous and powerful tornado in under 10 minutes.
"It's something that I've not seen personally, and certainly it's a rare thing to see," said Andy Boxell, a meteorologist with the National Weather Service in Springfield, Mo.
The storm follows on the heels of an already record-breaking year for twisters in the United States.
April saw 875 twisters, the highest ever recorded in that month, and 361 tornado-related deaths.
In total, there have been roughly 1,000 tornadoes so far this year, according to NOAA. However, the number of tornadoes alone doesn't necessarily relate to the number of people killed by the storms. Chance can play a big role: a twister that hits a heavily populated area, or one that comes with little warning.
In 2004, 1,817 tornadoes were recorded — the highest number ever — yet those storms killed only 36 people all year.
And 2011's wild weather streak may not be over yet. May is typically the most active month for tornadoes.
As of Monday evening, tornado warnings were in effect for counties in Virginia, Ohio, Kentucky, Kansas, Oklahoma and New Jersey.
- Infographic: Tornado Science
- The Tornado Damage Scale in Images
- Why Aren't There Tornado Safety Building Codes?
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