It’s an early October evening and high school sports are in full swing. That is, until someone sees lightning or hears thunder. Most places have a rule that if lightning is seen or thunder is heard, outdoor activities such as sports are put on hold until nothing is seen or heard for a set amount of time.
We often hear reports of high school football games being delayed because an official saw lightning, even in the distance. Sometimes fans are evacuated from the stands as well until the danger passes.
So, the question is, how far away from the actual storm can lightning strike?
National Geographic states that lightning, a result of electric charge differences within storms, can strike up to 10 miles away from the storm center. That’s particularly true if the bolt originates from the positively charged area of the storm.
As we said in a previous Weather Wise article, thunder can rarely be heard from more than 12 miles away, so if thunder can be heard, you are potentially in striking distance for lightning. This is the reason sporting events are evacuated. Most sports take place in an open field surrounded by metal stands. Since both are frequent lightning targets, they probably should not be full of people near a storm.
Many places use a 30-30 rule for lightning safety. If thunder is less than 30 seconds after lightning, the storm is too close for safety. People should move indoors and wait until 30 minutes have passed after the last seen strike or last thunder clap, no matter the conditions nearby.
Remember, lightning can travel up to 10 miles. So don’t let sunshine or clear skies fool you shortly after a storm!
Eggert works in the Indiana State Climate Office. He writes from West Lafayette.