NWS Dodge City, KS

OVERPASSES AND TORNADO SAFETY

Not a Good Mix.....

Many people mistakenly think that a highway overpass provides safety from a tornado. In reality, an overpass may be one of the worst places to seek shelter from a tornado. Seeking shelter under an overpass puts you at greater risk of being killed or seriously injured by flying debris from the powerful tornadic winds.

The idea that overpasses offer safety probably began in 1991, when a television news crew and some citizens rode out a very weak tornado under an overpass along the Kansas Turnpike. The resulting video continues to be seen by millions, and appears to have fostered the idea that overpasses are preferred sources of shelter, and should be sought out by those in the path of a tornado. In addition, news magazine photographs of people huddled under an overpass with an approaching tornado imply that this is the correct safety procedure. Nothing can be further from the truth!

In the Oklahoma City area in May, 1999, three people were killed and many had serious injuries by a violent tornado while seeking shelter under an overpass. Eyewitness accounts from others in the area indicated that roads were blocked at times as people stopped cars to run up into the small crevices under an overpass. Not only is the overpass unsafe as a shelter, blocking roads denies others the chance to get out of the storm’s path, and impedes emergency vehicles from their critical duties!

Wind speeds in tornados can be over 200 mph. These destructive winds produce airborne debris that are blown into and channeled under the overpass where people might try to seek shelter. Debris of varying size and types, including dirt, sand and rocks, moving at incredible speeds can easily penetrate clothing and skin causing serious injuries and possibly death. Very fine debris can also be forced into eyes causing injury or loss of sight. A person could even be blown out or carried away from the overpass by the fierce tornado winds. People positioned at the top of the overpass encounter even high wind speeds and more missile-like debris. Wind direction will also shift abruptly as the tornado passes tossing debris from all sides.

In the 1991 Kansas Turnpike video, the tornado was relatively weak when it passed near the overpass. A stronger tornado striking the overpass directly would likely have caused serious injury to those attempting to find shelter there.

The safest course of action when a tornado approaches is to get out of the tornado’s path, or to seek shelter in a sturdy, well-constructed building. Lying flat in a ditch, ravine, or below grade culvert also offers protection from flying tornadic debris. Do not try to outrun a tornado in a car. Be aware of your surroundings, check weather forecasts often in changing conditions and take personal responsibility for your own safety. Remember: Overpasses offer no protection from a direct hit from a tornado, and should not be used as shelter.

Tornado Safety-Related Internet Links:

National Weather Service Tornado Safety Brochure:
http://www.nws.noaa.gov/om/brochures/tornado.shtml

FEMA’s Taking Shelter from the Storm: Building a safe room inside your house:
http://www.fema.gov/mit/saferoom/

KANSAS SEVERE WEATHER AWARENESS WEEK

MARCH 13-17, 2006

NOAA National Weather Service Weather Forecast Office