NSSL/NWSFO fight public misperception that overpasses are safe shelters in tornadoes

Some people in Oklahoma on May 3, 1999, left their homes to drive to the nearest highway overpass to seek shelter from tornadoes. People jammed overpasses on the interstates 10-15 minutes before a tornado actually struck that night. Three of those people lost their lives. Of about 12 people who took shelter under the Shields Avenue overpass on I-35, one died and 10 others suffered serious and life-threatening injuries. Scientists at NSSL and the Norman NWSFO are disturbed by this public misperception that highway overpasses offer protection from tornadic winds, and they are taking steps to change this public mindset. One approach is to improve and intensify current efforts to promote and emphasize existing safety guidelines. The American Meteorological Society has recently adopted this policy: ". . .In spite of what many people might have seen in videos and photos, highway overpasses do not offer reliable protection from tornado winds and wind-driven debris. In fact, an overpass can produce a wind tunnel effect, depending on its configuration relative to the tornado. In addition, congregating under overpasses during threatening weather conditions creates an extremely dangerous traffic hazard." Another approach is to encourage people to have plans to prepare for tornadoes ahead of time. A third effort is to encourage "situational" awareness -- being aware of what can happen around you - including being aware of NWS forecasts and watches. Ideally, the first option for those in vehicles threatened by a tornado should be to get out of the tornado path. Secondly, they should seek shelter in a well-constructed building. But if their final option is a ditch, overpass, or staying in a vehicle, they are making a decision between bad options.