A guide to staying safe outside during a lightning storm.
Updated: June 5th, 2021
© IBTAT (aka Jeff Oliver)
No matter where you are on a hike, the possibility of a thunderstorm should not be ignored. It can be a dangerous and even life-threatening situation. We're here to help you learn how lighting works and understand the risks so you can find shelter and stay safe even in the worst storm.
A. Ground Current Lightning: The most common strike is ground current lightning, which causes nearly half of all lightning injuries. When lightning strikes the ground, it creates a current that travels through the ground and through your body. If you are standing with your feet together, it will travel up one leg and out the other. If you are lying prone or standing with your feet apart, the current will take longer to move through your body, increasing the damage.
B. Side Flash: A less common lightning strike is the side flash strike in which lightning hits a taller object like a tree and some of the current jumps to the person who was standing next to the tree. Moving 50 to 100-feet away from the tree decreases the likelihood of this strike. Conduction lightning occurs when a person is in contact with any metal object such as wiring or fencing that can conduct electricity. Though more common inside than outside, a conduction strike can occur inside tents and near fencing.
C. Direct Strike: The most devastating strike is the direct strike in which a person is hit directly with the bolt of lightning. In this strike, a portion of the current travels over the skin leaving a mark called a flashover while the remaining current travels through the body. A direct strike can cause extensive damage and is sometimes fatal.
D. Streamers: A similar and less predictable strike is a streamer which is an offshoot of a lightning bolt that forms as the main bolt approaches the ground. These streamers can strike far away from the original lightning strike. Though they are less powerful than the main bolt, streamers can still cause injury and death.
© ReptarHikes (aka Andrew Forestell)
There are three things that may cause a bolt of lightning to hit a person.
1. Height: Lightning is four times more likely to hit tall objects than short objects. In certain landscapes, that object may be a tall tree; in others, it could be a person. For that reason, mountain ridges and peaks are particularly risky areas to be in during lightning storms.
2. "Pointiness": Lightning is also attracted by pointy objects, which is why lightning rods often have a pointed tip. Tents, trekking poles, umbrellas... these are things that may put you at risk.
3. Isolation: Equally dangerous to being the tallest object in the area is being the only potential target around. Lightning is more likely to hit isolated objects, such as a lone tree or a person standing in an open meadow or on a body of water.
Lightning safety is more than just knowing how to find shelter in a storm. It's a multi-step process that starts even before you leave the security of your home.
Check the Weather Forecast: Check the weather before your hike and watch for thunderstorm warnings. Look for thickening and darkening clouds, developing rain, and increasing wind. Also, check out the National Weather Service’s weather forecast for any active alerts.
Plan the Time of Day: Storms are most common in the afternoons. This, of course, is not a guarantee. However keep in mind to try to schedule your hikes so that you avoid peaks, exposed areas, or high elevations during the afternoon.
Step 1: Assess the Distance. If an unexpected storm takes you by surprise, then you should evaluate how far away you are from the storm. Watch for a lightning bolt and then count the number of seconds until the next thunderclap. For every five seconds, the storm is one mile away. If you prefer the metric system, then the conversion is 1 km for every 3 seconds.
Follow the 30/30 rule to know when to seek shelter. If this time between when you see lightning and hear thunder is 30 seconds or less, then the storm is close enough to pose a severe threat. If you can't see the flash, just hearing the thunder 30 seconds apart is a back-up warning sign. Find a suitable shelter and wait 30 minutes or more after hearing the last thunder before resuming your hike.
Step 2: Act on Your Surroundings.
Spread out: If you are in a group, you should spread out about 50 to 100 feet apart to prevent the lightning's current from traveling between people and injuring everyone in the group.
Get down: In the middle of a storm, your first priority is to get off any ridges or peaks and move to a lower altitude. If the storm is moving too fast and you are stuck in an exposed area, then hiding behind a boulder is your safest option. Keep yourself low to the ground, but do not lie down on the ground, though, as the current from a lightning strike can travel through the earth and electrocute you.
Find a shelter: If you can get below treeline and onto a trail, you should seek a proper shelter such as a three- or preferably four-sided wooden shelter or a car at a trailhead. These areas don't attract lightning and will keep you dry. Your next best choice is a dense stand of uniformly sized trees in a forest or a low-lying area such as a ravine or a depression in a rolling meadow.
Adopt the Lightning Crouch: As a last resort, experts recommend you assume the lightning position - crouch on the balls of your feet with your heels touching, tuck your head toward your knees and cover your ears with your hands. This position reduces your overall height and minimizes your contact with the ground.
Lightning is an electrical discharge caused by an imbalance of positive and negative charges between the clouds and the ground. During a storm, particles of ice, rain, and snow collide inside a storm cloud, causing it to build up a negative charge. At the same time, tall objects like towers, trees, and buildings on the ground build up a positive charge. A lightning bolt is a bridge that dissipates both of these opposite charges and restores the balance between the ground and the sky.
A lightning strike is no laughing matter. A single lightning bolt can carry up to two billion volts of electricity. At 50,000 °F, it is also five times hotter than the surface of the sun. Any strike, direct or indirect, can cause severe injury or possibly even death. Thankfully, casualties are rare. Among the thousands of people who are struck by lightning each year, approximately 90 percent survive. Though they heal physically, many of these people suffer lasting neurological and emotional effects.
Thankfully, lightning strikes on a person are not a common occurrence. You have a 1 in 12,000 chance of being struck by lightning during your lifetime. Among those who are hit by lightning, only a small percentage are hikers. Statistics show that most people who get struck by lightning are on - or near - a body of water when they are struck, either fishing, boating, or swimming. Even though the odds are against being hit, we need to be careful, especially men as you are four times more likely to be hit by lightning than your female counterparts.
A lightning strike causes an electrical shock that disrupts the nervous system and sometimes the heart. It also produces a searing heat that burns the skin and an explosive force that knocks people off their feet. Most people survive a lightning strike, but they are usually severely injured and require immediate medical attention. It is imperative that you get them off the mountain and to a hospital as soon as possible.
Check with everyone in your group after a strike to ensure they are not injured. Note that it is safe to touch an injured person as the electricity does not stay in their body.
Here are some the first aid procedures we recommend following:
By Kelly Hodgkins: Kelly is a full-time backpacking guru. She can be found on New Hampshire and Maine trails, leading group backpacking trips, trail running or alpine skiing.
About Greenbelly: After thru-hiking the Appalachian Trail, Chris Cage created Greenbelly to provide fast, filling and balanced meals to backpackers. Chris also wrote How to Hike the Appalachian Trail.
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