Thunderstorms typically are 15 miles or less in diameter and last an average of 20 to 30 minutes. Downbursts and straight-line winds associated with thunderstorms can produce winds of 100-150 miles per hour. Of the estimated 100,000 thunderstorms in the United States each year, only about 10% are classified as severe. Lightning, a major threat during thunderstorms, is responsible for more deaths annually than tornadoes. Since lightning strikes are very unpredictable, the risk to individuals and property can be significant.
A SEVERE THUNDERSTORM WARNING means that there are currently severe thunderstorms in the area or that one is imminent based on Doppler radar. These storms are potentially accompanies by cloud-to-ground lightning, high winds, and hail. Thunderstorms are classified as “Severe” if they produce hail that is dime size (.75” in diameter or larger) and/or wind gusts to 58 mph or more, or produce a tornado.
During a thunderstorm/lightning event, you should:
- Seek sturdy indoor shelter and stay away from windows and doors.
- Do not touch items that conduct electricity.
- Avoid contact with electrical equipment or cords. Unplug appliances and other electrical items such as computers and turn off air conditioners.
- DO NOT lie on concrete floors and do not lean against concrete walls.
- Avoid natural lightning rods such as a tall, isolated tree in an open area.
- Avoid contact with anything metal—motorcycles, golf carts, golf clubs, and bicycles.
- If you are driving, try to safely exit the roadway and park. Stay in the vehicle and turn on the emergency flashers until the heavy rain ends
CALCULATING LIGHTNING DISTANCE:
Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any landfall. To estimate your distance from the lightning flash, use the “Flash to Bang” method: if you observe lightning, count the number of seconds until you hear thunder. Divide the number of seconds by five in order to get the distance in miles.
Lightning can strike up to 10 miles from a storm. Seek shelter as soon as you hear thunder or see lightning. Go to a safe location if the time between the lightning flash and the thunder clap is 30 seconds or less. The chance of being struck by lightning is approximately 1 in 600,000. However, this can be reduced even further by following safety precautions. Lightning strikes are serious medical emergencies requiring immediate attention. Contrary to popular belief, lightning strike victims carry no electrical charge and should be attended to immediately.
HPU Lightning Response:
When lightning is detected within 8 miles of campus, all pools will be evacuated and card access restricted. Pool access will be restricted until the storm passes (30 minutes after a lightning strike within 8 miles). Campus Rec, Athletics and Security officials will clear athletic and intramural fields.