Archive for May 3rd, 2012

Anniversary of the May 3, 1999 Tornadoes

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On May 3, 1999, forecasters at the Storm Prediction Center faced an uncertain situation. They knew that severe weather was going to occur across the Plains states. But would the greatest threat come from tornadoes? Or a squall line? Did the threat warrant a high risk classification?

Data from the Tucumcari, New Mexico wind profiler allowed them to see that upper levels winds were stronger than forecast by the models. This gave them the confidence to upgrade to a high risk of severe weather. Emergency officials took their cues from this move, and the level of preparedness was much higher than it would have been otherwise.

Their enhanced prediction was certainly warranted as 76 tornadoes struck the Plains. It was the worst outbreak in the Sooner State since the 1947 Woodward tornado swarm. The May 3, 1999 tornadoes killed 43 people in Oklahoma and injured 680. More than 1,700 homes and businesses were destroyed. Five deaths, one hundred injuries and heavy damage were also incurred in the Wichita, Kansas metro area from a tornado that was one mile wide at times. Six other fatalities occurred in Kansas.

Multiple supercell thunderstorms produced many large and damaging tornadoes in central Oklahoma during the late afternoon and evening hours. Some of these storms were killers, including the twister which moved through and/or near Chickasha, Dover, Shawnee, Moore and the southern Oklahoma City metropolitan area. This tornado was a very strong F5, making it the first F5 in Oklahoma in 15 years.

As a matter of fact, when the tornado was near Moore, a truck-mounted Doppler radar measured a windspeed of 318 mph, the highest ever observed in a tornado. That windspeed would make the twister just one mph from being an F6, which has never officially happened.

It was the first F5 tornado ever to directly affect a major city. It was also the most expensive tornado in U.S. history to that time. It caused $1.2 billion in damage and killed thirty six people. The Oklahoma City tornado ranks as the sixth deadliest twister in the history of the state.

A sidebar to the May 3, 1999 severe weather outbreak: a misconception had developed in the general public that if a tornado was approaching, the girders underneath a bridge would provide protection. The myth stemmed from dramatic footage from a news crew during the Andover, Kansas tornado of 1991 that sought refuge under an overpass as the tornado struck it directly. Unfortunately, several people were killed during the Oklahoma City tornado as they hid underneath an interstate bridge.

What do you do if you are driving and see a tornado? The safest thing is to avoid the storm all together. Monitor weather alerts and avoid driving into a severe thunderstorm. But if you find yourself near a tornado, you can easily drive away from it if you know which way it is moving. Don’t try to outrun it unless you know it is moving slower than you are traveling. Rather, drive at right angles to the path of the tornado. If it is heading northeast, you drive southeast if you are south of the path. If you are north of the path, drive northwest. Be alert to other tornadoes that may be developing away from the first funnel.

If there is no clear path or you don’t have time, the best thing to do is to abandon your automobile and seek shelter in a building on the lowest floor in an interior room without windows.

If no shelter is available, all of your options are probably bad. You can find a ditch or low spot and cover your head. Do not block travel lanes on the highway and prevent people from being able to drive to safety. Not a good option.

Some recent new advice says that you can take your chances in your car with your seatbelts on trying to lie low in the seats to prevent being hit by flying debris. Remember, that projectiles can easily penetrate your vehicle and seriously injure or kill you. And you can only hope that the tornado doesn’t take your vehicle airborne, as we have seen countless times, only to deposit it hundreds of yards away in a mangled, unsurvivabe heap of metal. Not a good option either.

You can do what UPS Driver Jimmy Jones did as a tornado roared down on top of him on I-359 in Tuscaloosa on April 27th. He had no choice but to run up under a highway overpass and hide in the girders as the tornado passed over. He was lucky as the design of the girders was such that it left him a recessed place to hide from the wind. An absolute last resort.

Several people on May 3, 1999 gambled with the girders and the design of the bridge they chose did not afford them protection. They were sucked from the girders, blown long distances and killed. Don’t take a chance with a bridge. Don’t put yourself in that position to begin with!

Another note from the 1999 tornadoes: forecasters at the Storm Prediction Center in Norman OK were faced with the situation of a major tornado on the ground threatening their operational facility. As a major F5 tornado was approaching the Oklahoma City metro area from the southwest, the SPC notified its backup, the Air Force Weather Agency at Offutt AFB in Omaha NE that they might have to assume operational responsibility if the tornado approached Norman. The storm remained several miles west of the facility and was visible from the SPC roof. Fortunately, none of the forecasters homes were damaged by the tornado.

The excellent forecasts and warnings undoubtedly helped save hundreds of lives that fateful day in Oklahoma and Kansas. The warning process works well today with strong to violent tornadoes especially. Those are the ones that cause most of the fatalities. Make sure you have a plan for any place you may be when severe weather is expected. That includes having redundant, reliable sources for warning information wherever you are.

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