OKLAHOMA CITY (AP) _ A tornado that left a 24-mile path of destruction in Maryland last weekend pales by comparison to a twister that killed 44 people in Oklahoma three years ago.
Six people were killed Sunday as a huge swarm of thunderstorms rumbled across the Tennessee and Ohio valleys and all the way to the East Coast. In Maryland, three people were killed and at least a hundred were injured.
A preliminary assessment by the National Weather Service rated the twister at F5 on the Fujita scale, the most powerful level.
But Barbara Watson, a warning coordination meteorologist for the weather service in Sterling, Va., said the storm registered in the low end of the F5 category.
``Even if it is classified as an F5, it's not as bad as what happened in Oklahoma,'' Watson said.
The Maryland tornado would be the first F5 twister since a tornado on May 3, 1999, cut across one-fourth of Oklahoma.
For many Oklahomans, it's hard to imagine that a tornado that big could ever happen again.
Such tornadoes account for less than 1 percent of the total amount of tornadoes in the United States every year. Typically, there are 1,200 tornadoes per year causing more than $400 million in damage.
``Some people refer to it as a once in a lifetime event,'' said Rick Smith, the warning coordination meteorologist for the weather service in Norman. ``The way statistics and climatology work ... we can't guarantee that won't happen again.''
``The key is to be prepared at all times in tornado-prone parts of the country. That's what saves lives.''
Oklahoma television stations break into regular programming during severe weather outbreaks to warn viewers of potential dangers. Authorities encourage residents to own weather radios that emit an alarm when a tornado warning is called. Tornado sirens are plentiful.
The May 3 tornado started near Chickasha. It cut through rural Bridge Creek, hit Moore, crossed southwestern Oklahoma City and roared into the suburbs of Midwest City and Del City.
A separate tornado that night flattened much of the town of Mulhall, about 40 miles north of Oklahoma City.
Another tornado tore through Stroud, destroying a shopping center and shipping company. Damage from the tornado eliminated 600 jobs in the town of 3,000.
A concrete slab now sits where the mall once stood and the shipping company relocated elsewhere.
In Midwest City, where some of the severest damage occurred, property valuation decreased by about $10 million because of the tornado. The school district is still trying to recover from the decrease in property tax revenue.
Research from the May 3 tornado has helped forecasters learn how to better track storms. Engineers studied damage to 8,000 homes and businesses to learn more about building tornado-resistant structures. Medical studies were done about the types of injuries suffered in tornadoes.
A computer simulation program was developed that helps train forecasters to monitor severe weather.
The program tests the capabilities of forecasters to issue weather warnings as storms develop.
``The simulator was kind of born out of the May 3 outbreak,'' Smith said. ``There were some ideas floating around. That event helped to condense those ideas into a plan.''
Jim Travers, the meteorologist in charge of the Baltimore/Washington Forecast Office of the National Weather Service, said that the day after the Maryland tornado, forecasters were studying the unusual event.
``It really serves as a tremendous learning opportunity,'' he said. ``It's about a good a chance as you can get without actually doing it.''