Lightning is a spectacular weather phenomenon, and I have been reminded of its awesome power during the afternoon storms here in North Carolina. Last week we were starting out a hike at the 6,000 feet altitude in the Mount Mitchell mountain range when a storm quickly formed. Luckily, we were able to quickly walk down to lower ground and take cover. Not everyone is that lucky. We later learned that a nearby backpacker was struck and killed by lightning that same weekend.
During another thunderstorm the following week, a 20’ tree branch missed falling on my head by a few seconds. These two incidents were the inspiration for this article. I hope these tips will keep you safe when you are caught outdoors during a storm.
How to reduce your chance of getting struck by lightning when you are outdoors during a storm
- Seek a safe area. Move away from high ground, water, open spaces, metallic objects, and tall, exposed objects (even if they offer shelter from the rain) as soon as you see lightning or hear thunder.
- Go to lower ground. Do not seek shelter within trenches, shallow caves, ledges, hollows, or valleys containing water. The best place to seek shelter is under/near groups of small trees/shrubs of uniform height. Remove all metal objects.
- Avoid solitary trees and open areas. You do not want to be near the tallest object as lightning strikes the tallest object in its path.
- Recognize the signs of an imminent lightning strike. If lightning is about to strike close to you, you may feel a tingling sensation in your skin, your hair may stand on end, you may also hear a high-frequency crackling sound, you may notice a blue halo around objects (St. Elmo’s Fire), or you may have a metallic taste in your mouth. If you detect any of these signals, assume the lightning crouch immediately.
- Assume the lightning crouch position. Keep your feet together and crouch down on the balls of your feet. Do not allow your hands or other body part to touch the ground. Keep spread out from others, with 10-20 feet of space between each person. Crouching reduces the surface area of your body making you a smaller target. Any current ricocheting off a nearby object is more likely to travel over your body versus the vital organs through your body.
Some interesting facts about lightning
- Thunderstorms develop from tall, puffy, cumulonimbus clouds. These clouds are formed from rising air columns causes by intense heating of the sun. Cumulus clouds can reach a vertical height of 5 -10 miles during hot, humid days. The temperature within the cloud is below freezing. As air move up and down the cloud, a current is formed. If currents continue to form, they will develop into localized thunderstorms. The rapid heating and cooling of air near a lightning strike is what causes thunder. Heavy rain occurs as the water vapor quickly condenses when exposed to the air. Learn how to recognize storm clouds and plan accordingly.
- Estimate the distance between you and the lightning. Count the number of seconds from the time you observe a lighting bolt until the time you hear its thunder. Divide this number by 5 to get the distance (in miles) of the lightning from you. For example, a 10-second count means you are 2 miles away (10/5). Anything less than 6 miles away (30 seconds or less after a flash) is too close. Seek shelter.
- Why squatting keeps you safe. Trees, poles, and other tall objects, are conductors of lightning. If lightning strikes an object, the current may not be completely discharged by the ground directly underneath the strike. Instead, electric current will often travel across the ground before it is charged. Therefore, any object in the path of current will be impacted. Squatting down on your feet reduces the surface area of your body so the impact of the electric current traveling across the ground is lessened. This principle works because light travels faster than sound. You hear the strike by a delay of approximately 5 seconds from the time the bolt actually occurred.
- Pine, Oak, and Elm trees are the most frequently struck trees since they usually stand taller than other species. When a tree is struck by lightning, the water & resin within the tree turns to gas. The gas as it tries to escape within the structure, creates a high pressure, and literally explodes timber and bark. These shards of wood can create high-velocity projectiles.
Some trees are “safer” than others. Large trees without a tap root, or those that contain a high biomass root, offer better protection. In other words, these are trees with root systems that spread out into the earth several times the width of their trunk. When lighting strikes, the large complex root structure helps dissipate the lightning charges quickly.