Staying Safe in the Outdoors During Storms: Q&A with NOAA Lightening Safety Expert John Jensenius

Lightening in New Mexico.
Image courtesy of the NWS.

According to the National Weather Service, about 34% of lightening strike victims are outside far from safe shelter engaging in popular summertime activities such as bicycling, hiking, camping, and fishing. Most lightning victims are close to safe shelter but wait too long to get there. Summer storms can be both stunning displays of Mother Nature's power and incredibly scary if you're caught in one outdoors. NOAA lightening safety expert John Jensenius has a number of tips and thoughts about how to stay safe when we're playing outside during storm season.

Is there any sort of pattern to lightning strikes nationwide?

Yes, areas with high levels of heat and humidity tend to get the most lightning as these are two of the ingredients needed to produce a thunderstorm.  In the U.S., Florida and the Gulf Coast tend to get the most lightning.  The U.S. Southeast Coast and Mississippi Valley also receive quite a bit of lightning.  A map of the average yearly lightning strike density can be found here.

If I'm outside in the summer and hear thunder, how can I tell how far away it is?

In order to tell how far away the lightning is, you must first see the flash of lightning.  Count the number of seconds between the flash and thunder, divide by 5, and that tells you the distance (in miles) to the lightning (10 seconds equals 2 miles).  Thunderstorms also have in-cloud lightning which typically develops shortly before the cloud-to-ground lightning.  Unless it is dark outside, you probably won't see the actual flash.  However, a crackling or rumbling aloft is a sure sign of a charged atmosphere and the imminent threat of cloud-to-ground lightning.  More information can be found here.

At what point should I start seeking shelter? Can I tell how fast storms are moving or if they'll pass me? (from @cdnrockiesgirl)

You can only hear the sound of thunder about 10 miles from a storm.  And...lightning can strike 10 miles from a storm.  So, if you hear thunder, you're likely within striking distance of the storm and need to get to a safe place immediately.  "When thunder roars, go indoors!"  Depending on the situation, you may need to head toward a safe shelter much sooner, especially if you need extra time to reach the safe shelter.  If you know thunderstorms are possible on a particular day and the sky starts to show signs of a developing storm, don't wait for the first lightning strike because the first flash is just as deadly as all the other flashes.

Where are the best places to seek shelter from lightning? What are the worst?  

There are only two good places -- in a substantial building that has wiring and plumbing throughout or a hard-topped metal vehicle.  If lightning strikes a substantial building, it will usually follow wiring and plumbing to the ground.  Since it follows wiring and plumbing though, you don't want to be connected in any way to either (or anything plugged into the electricity).  If lightning strikes a hard-topped vehicle, it will follow the metal shell around you.

If I'm on, say, a 14er in Colorado, with little cover, what are my best options? (from @whitneyio)

Being outside is very dangerous.  If you're outside and can't get to a safe place, we tell people to avoid situations that would increase the risk of being struck. Lightning tends to strike the tallest object in the immediate area -- so, you don't want to be the tallest object, nor do you want to be near tall objects.  People continue to be killed every year taking shelter under tall trees. 

There are no "good" options as there is little you can do to protect yourself from a nearby lightning strike.  Because lightning would tend to strike the ridge lines or peaks more often than other areas, you'd want to avoid those. However, being in this situation is very dangerous and your life is at the mercy of the random nature of lightning strikes.  If at all possible, you should plan your mountain hikes early in the morning and be off the mountains before thunderstorms develop.  Thunderstorms develop very rapidly over the higher peaks in Colorado and once they start to develop, there is little time to get to safety. 

Am I more likely to get struck by lightning if I'm hiking at elevation?

Elevation is a factor in thunderstorm development, but there are other factors (such as heat, humidity, and atmospheric stability) that also factor into thunderstorm development and the amount of lightning.  If you take another look at the map of lightning strikes, you will notice an increase in lightning over the higher peaks in Colorado.  However, you don't see an increase in the mountains along the Pacific Coast or even along the Appalachians Mountains near the East Coast.  In addition, the most lightning in the U.S. occurs in relatively low areas.

I've never experienced a thunderstorm or lightning in the winter. Why? Are there places that do?

Yes, very well developed winter storms can produce lightning in the central and eastern United States.  The reason that you don't see lightning very often in the winter is that the atmospheric conditions needed to produce a charged cloud are relatively rare and only occur with very well developed winter storms.  Lightning in winter storms is just as dangerous as lightning in summer storms.

I generally see lightening as scary and dangerous. Are there good things about storms?

Dangerous and scary - yes, especially if you’re not in a safe place.  If you're in a safe place though, it can be interesting and fascinating to watch.  I have always been interested in science of lightning, but also work very hard to make people understand this dangerous and potentially deadly killer.  In my mind, being scared of lightning equates to a healthy respect for something that can kill you.  Always be careful and always plan your activities to avoid the threat.

Interviewee John Jensenius.
Thank you!

As for other benefits, lightning plays a part in the earth's natural "nitrogen cycle."  As lightning passes through the air, it "fixes" nitrogen which means it combines nitrogen and oxygen to form nitrogen oxides.  The nitrogen oxides are then carried to the earth by raindrops and serve as a natural fertilizer for plants on the ground.

Huge thanks to John for taking the time to answer questions about lightening and lightening safety in the outdoors! 

Do you have anything else you'd like to know? Have you had an experience with lightening or storms during an outdoor adventure? Leave a comment!