Fastest twister reached 318 mph
What is the fastest speed ever recorded for a tornado and a hurricane?
The tornado that hit the Oklahoma City suburbs of Bridge Creek and Moore on May 3, 1999, registered a wind speed of 318 mph, the highest on record, according to the National Weather Service. It was measured by a truck-mounted Doppler radar unit called Doppler on Wheels.
The tornado that hit Moore on May 20 had estimated wind speeds between 200 and 210 mph.
Cyclone Olivia, which hit Australia in 1996, had wind speeds measured at 253 mph, according to the Hurricane Research Division of the National Oceanic and Atmospheric Administration.
Hurricane Camille, which hit Louisiana, Mississippi, Alabama and Florida in 1969, and Hurricane Allen, which hit Mexico and southern Texas in 1980, had estimated wind speeds of about 200 mph. But "such winds are inherently going to be suspect as instruments often are completely destroyed or damaged at these speeds," according to the Hurricane Research Division's website.
Few basements in Oklahoma
Oklahoma and Kansas are in Tornado Alley, so why don't they have basements?
Cost is one of several factors why more homes in Oklahoma don't have basements, according to published reports. Mike Barnett, a custom home builder in Oklahoma, told CNN.com that a small basement would cost $15,000 to $20,000, adding that none of the houses in his recent 51-home development have one. He said about 2 percent of Oklahoma City area residents have basements and about 10 to 15 percent "have some kind of cellar."
Low appraisals for homes with basements — basement space is not reflected in property appraisals, according to The Oklahoman newspaper — discourage people from having them built. Caleb McCaleb of McCaleb Homes told the paper that myths about the red clay soil and water level in the state keep people from building basements. "If the basement is designed correctly, then water intrusion and ground movement are not problems with a residential basement," he told the newspaper.
Mike Hancock of Basement Contractors Inc. told CNN.com that more Oklahoma home buyers are turning to basements. "I've got 32 basements to put in the ground right now," he said.
According to 2005 data from the National Association of Home Builders, only 0.5 percent of homes built that year in the West South Central region of the United States had basements, the lowest percentage in the country. There is no ordinance in Moore, Okla., where 24 people were killed by tornadoes on May 20, that requires shelters in homes, schools or businesses.