Campus News

UK Expert Talks About Lightning Safety

LEXINGTON, Ky. (May 24, 2010) − "If you can see it, flee it…if you can hear it, clear it."

Those phrases are among the reminders from the National Lightning Safety Institute on how you can best protect yourselves and your loved ones during the spring, summer, and fall thunderstorm season.

Tom Priddy, longtime University of Kentucky Extension Agriculture Meteorologist, Department of Biosystems and Agricultural Engineering, and director of the Ag Weather Center for the College of Agriculture, said lightning basically is, "Electricity on the move following the path of least resistance."

As a thunderstorm builds, the whole cloud fills up with electrical charges,  usually with a negative charge closest to the earth.  Since opposites attract each other, that causes a positive charge to build up on the ground beneath the cloud.  The ground's electrical charge concentrates around anything that sticks up, such as mountains, lone trees, people, or even blades of grass.  The charge streaming up from these points eventually connects with a charge reaching down from the clouds, and zap, lightning strikes.

"Lightning can occur up to 10 miles away from the center of the thunderstorm," said Priddy. "When you hear thunder, that means lightning is occurring somewhere."

Lightning typically strikes the highest point in an area, but there are no absolutes when it comes to this phenomenon.

While this is a great time of the year to enjoy water sports and activities such as fishing, Priddy said that being on or in the water during a thunderstorm is the worst place you can be. "By all means, get out of the pool or lake and take shelter immediately," said Priddy. "However, do not take cover under a tree. If there is no alternative
shelter available, the Lightning Safety Institute recommends you roll up in a
big ball and squat down as close to the ground as possible.

"If you are outdoors and there's lightning, get indoors immediately. But once you are inside, stay away from windows, refrain from talking on a land line telephone, and don't take a shower or bath until the storm passes. Lightning occurring up the street can enter your home through electrical lines and that's why you should not be on the phone when there is thunderstorm activity. Likewise, the plumbing coming into your house can conduct electricity and bring it through the faucet into your shower or tub," said Priddy.

Sound travels about one mile in five seconds.   When the amount of time between a bolt of lightning and the sound of thunder is decreasing, it means the lightning is getting closer to you. The National Oceanic and Atmospheric Administration (NOAA) reminds people of the '30/30 rule.' If lightning precedes thunder by less than 30 seconds then the storm is too close and you need to seek shelter. After the storm, wait at least 30 minutes before leaving shelter and resuming outside activities.

Priddy said one of the best investments people can make to protect themselves from lighting and other severe weather is the purchase of a NOAA weather radio. "These radios cover 97 percent of the U.S. population and provide an authoritative early warning system."

With the large expanses of open land on farms in Kentucky, farmers need to be very aware of approaching storms, as do golfers.

Lightning is the second leading source of storm deaths in the U.S. in most years and hundreds of people annually sustain permanent injuries as a result of being struck by lightning.


If you still need another reminder about lightning safety, remember this saying: "When thunder roars, get indoors."