Oklahoma, Alabama, Joplin: Why we're seeing so many tornadoes and superstorms
The superfunnels that hit Tuscaloosa, Ala., in late April and Joplin, Mo., on Sunday, are generated by storm systems whose journeys across the country are slowed by a roadblocked jet stream.
Rescue crews continue to comb through the storm-swept streets of Joplin, Mo., following Sunday night's powerful tornado, which cut a swath of destruction through the center of the city more than six miles long and nearly a mile wide.Skip to next paragraph
At least 116 people have died, according to emergency managers – the highest number of fatalities from a single tornado in over 60 years. At least 17 survivors have been pulled from the rubble the twister left in its wake.
The last twister with a similar toll appeared during a 1953 tornado outbreak in the Eastern US. Some 116 people were killed when a tornado struck Flint, Mich. The same outbreak sent a mile-wide tornado through Worcester County in central Massachusetts – a part of the country where tornadoes of that scale are rare – resulting in the deaths of 94 people.
On Monday, National Weather Service forecasters said the Joplin tornado packed winds of between 192 and 198 miles per hour, based on a preliminary survey of the damage. After more survey work the next day, they raised the estimated wind speeds to more than 200 m.p.h. on Tuesday evening, giving the tornado a rating of EF5 – the most-destructive designation, said Bill Davis, meteorologist in charge of the National Weather Service (NWS) forecast office in Springfield, Mo., who headed the survey team.
President Obama expressed his sympathy for the stricken and pleded federal support "until every home is repaired, until every neighborhood is rebuilt, until every business is back on its feet," according to a statement released by the White House on Tuesday.
Even as rescuers continued their search, the conditions remained ripe for additional strong thunderstorms – capable of spawning intense tornadoes – in a four-state area that included Joplin, according to the NWS Storm Prediction Center in Norman, Okla.
Severe weather over Monday night, during which two police officers searching for survivors were reportedly struck by lightning, hampered rescue efforts for several hours.
What's causing all the superstorms?
Tornadoes like the ones that hit Joplin on Sunday and Tuscaloosa, Ala., on April 27 are relatively rare, according to David Imy, a forecaster with the Storm Prediction Center. Some 75 to 80 percent of the tornadoes in the US are fairly weak, "with winds of 100 miles per hour, give or take some," he says. They tend to be short-lived.