When warning is not enough
Certainly, Oklahoma City knew it was coming. Meteorologists predicted it. Local television helicopters tracked it. Local storm sirens sounded. And still, the powerful, mile-wide tornado that plowed through central Oklahoma May 3 took dozens of lives.
The series of storms, which hit Texas and Kansas as well, is the worst tornado-related disaster to hit the United States in at least 15 years.
As residents begin the solemn task of cleaning up from a series of twisters almost freakish in number and intensity, the devastation is spurring another look at the science of prediction - and preparedness. Although both have improved dramatically in the past five years, violent storms still cause far too many fatalities in the US, experts say.
"This is really hard," says Harold Brooks, a meteorologist with the National Oceanic and Atmospheric Administration (NOAA) National Severe Storms Laboratory in Norman, Okla. You can warn people that a tornado has touched down, he adds, but it moves in unpredictable ways and if people who hear the warning see no tornado, they may not take future warnings as seriously.
In Oklahoma alone, at least 40 people were killed, according to emergency officials.
"In terms of Oklahoma County and the central Oklahoma area, it's the largest we've ever seen," says Mike Hammer, spokesman for Oklahoma County Emergency Management Office in Oklahoma City. "At times, it was a mile wide - just total walls of debris."
Officials at the National Weather Service said the storm packed winds of at least 207 miles per hour, the second most powerful category of tornado.
President Clinton was set to declare several Oklahoma and Kansas counties disaster areas, providing federal aid to areas damaged by tornadoes, and he dispatched the head of the Federal Emergency Management Agency to Oklahoma City. "My heart goes out to the people of Oklahoma and Kansas," Mr. Clinton said May 4. "Our top priority is to make sure people are safe, that everyone is accounted for, and that initial cleanup can begin."
Fortunately, local officials got the word early. The National Weather Service's Storm Prediction Center, which tracks severe weather nationwide and issues severe-weather "watches," kept upgrading its level of concern, finally reaching "high risk" of severe storms.
Weather Service officials note that average tornado-warning lead times have doubled to 12 minutes as a result of a decade-long effort to improve weather sensors, computer-based forecasting models, and a fundamental understanding of these powerful micro-storms, whose winds can top 300 miles an hour.
"Twelve minutes may not seem like much," acknowledges spokeswoman Randee Exler, "but it's enough time to get out of harm's way."
Oklahoma City had even more warning. As the storms formed and moved through Grady County, Oklahoma City had from 20 to 30 minutes notice that the oncoming system was producing tornadoes, says NOAA meteorologist Harold Brooks in Norman. "From what I can tell, the Weather Service performed very well."
Media coverage and emergency warnings - plus the timing of the storm during waking hours - held down fatalities. "We had quite a bit of time to prepare," recalls Oklahoma County's Mr. Hammer. "It could have been five to six times worse if we'd had no warning whatsoever."
And thanks to two local TV helicopters that tracked the storm as it moved toward Oklahoma City, residents who turned on their televisions knew when to head for shelter.
Marjorie Revah was making meatballs when her children raced in to warn her about the tornadoes. Together they cleared out a closet and filled it with blankets and pillows, then Ms. Revah went back to making meatballs. "The kids were really worried. In fact, they were getting hysterical. But I told them I could see that [the storms] weren't by our house, so I kept on cooking," she says. Because of the Doppler radar at the local TV stations, "they can tell you street by street where the tornado is."
Unfortunately, the warnings also encouraged gawkers who drove in cars to view the coming storm. At least four people were killed in their cars, Hammer says.
In some cases, the storm was so strong it collapsed houses, shearing some at the foundation. Oklahoma County officials estimate 1,000 to 1,500 homes and businesses have been damaged or destroyed.
The fatalities are forcing weather experts to look at further improvements. One is to make storm warnings more reliable so people will take them more seriously. Too often, weather experts say, warnings are issued and nothing happens, lulling people into a false sense of security.
In addition, known construction techniques for new construction and for renovations, Mr. Brooks says, can enable a home to withstand, with minor damage, all but the strongest 10 percent of tornadoes that hit the US.
*Alexandra Marks also contributed to this story.