SOL: How to Survive a Thunderstorm
Everyone’s been there: It’s a beautiful summer afternoon, warm with light winds and a few puffy clouds on the horizon, but nothing overhead.
You and your friends are enjoying your favorite hike, and as you gain the ridge you see tall, white clouds on the horizon; too far away to matter to you. You head for the summit as the sky turns grey and you think, “It’s mid-summer, we aren’t going to get rain.” When you hit the summit, you feel your hair kind of stand up, and the rocks seem to be buzzing. You finally realize you’re not in a good place …
Afternoon thunderstorms can wreak havoc in the mountains, in the deserts, and on the water we love to play in. They sneak up on you faster than you think, and if you’re on an exposed ridge or summit, they can be deadly. The yearly average number of lightning deaths in the US is 53, and the most common places are on or near the water and under or near trees.
Avoid Getting Caught in a Thunderstorm
So how do you stay safe during a lightning/thunderstorm? The easiest and safest method: Don’t get caught in one. Make sure you understand enough about the weather to know when one is coming up. It’s not surprising that July is the most popular month to get killed by lightning, with an average of 16 deaths during that month every year. Monsoonal thunderstorms may sound like they only happen in the Amazon, but they’re a common thing in the western US during the late summer months. Heat and moisture buildup during the day means an “afternoon thunder bumper” between 3 and 5 p.m.
Recognize the signs of a building thunderstorm so you can know to bail before it’s too late. There are several ways to know if conditions are right for a thunderstorm. The telltale signs are:
- Tall, building cumulus clouds—these are the big, puffy white ones. If they start to grow really tall (500 – 1000ft) you know conditions are right for a thunderstorm.
- South winds beginning to pick up. Wind always blows toward pockets of low pressure. Storms typically blow in from the northeast (depending on where the jet stream is), so as the storm builds the wind will blow into it; as it gets closer the wind will swing around to the west, and then right before the storm hits, the wind will be coming from the direction of the storm.
- Virga. Virga refers to visible rain shafts coming from the bottom of a cloud that don’t touch the ground due to evaporation or sublimation.
- Tall, dark, anvil-shaped, flat-bottomed clouds. This is a thunder cell. If you see a cloud like this, you need to get moving.
- Finally, if your hair is standing on end, or if you feel like the rocks around you are “buzzing,” you’re in a bad place. This means there’s an electrical charge in the air, and this is a sign that some serious lightning is about to happen.
What to Do If You Get Caught in a Thunderstorm
So let’s say you’ve ignored these signs and you find yourself caught in a thunderstorm. What do you do? If you’re on the water, get the hell off the water. There’s no safe place to hide on the water. Being in your boat won’t protect you from lightning unless you have a big boat with a cabin and a lightning protection system. Seven of the 23 lightning deaths in 2013 were either on or near water.
If you’re in the mountains, you need to assess your situation and decide what to do. Here are some guidelines:
- If you’re above the tree line on an exposed ridge, get lower. Don’t hide under trees; five of the 23 deaths last year were people under or near trees.
- If you’re in a forest and can’t find a clearing, find the lowest group of trees you can and try to stay away from their bases.
- If you can, look for a cave, or find a low, open space, a meadow or a clearing of some kind, and head to the lowest ground possible. The entrance to a cave can be hazardous, so move in and out as quickly as possible.
- Large talus fields present difficulty; the best thing is to get off of them. If you find yourself on one and have no time to get off, try to find the lowest spot you can, and stay away from taller rocks. Rocks can attract lightning same as anything; if there’s an appealing shelter under a rock, make sure it’s not very tall.
- If you’re in an open space, spread out about 20 feet apart from each other and away from tall trees, and try to stay dry and warm. Wait for the storm to clear, or until you haven’t had lightning closer to you than 10 seconds (mark the time from when you see the flash to when you hear the thunder) for ten minutes, and then get to safety.
Once you’ve found your place of refuge, whether in a group of shorter trees, the back of a cave, a low spot in a meadow, or a low spot on a talus slope, get into the lightning position. Minimize your contact with the ground by standing on a foam pad with your feet close together and crouch or squat to lower your overall height. If you don’t have a foam pad, you can use your pack. Make sure to keep your shoes on, as the sole will help insulate you. The idea is to minimize your contact with the ground and stay insulated from the ground.
If you’re at your camp, evaluate how close a proper shelter is. If a building or your car is nearby, then head for it. Otherwise, evaluate the safety of your camp spot. Are you near tall trees? Are you on a highpoint in a clearing? If your tent is not near tall trees, and you’re in a low spot in a clearing, you’re probably best staying in it. Remove all the metal items you can and put them far away from your tent. Try to stay insulated from the ground using your sleeping pads and backpacks. The exception would be if you have an old tent with steel or non-anodized aluminum poles, as these will conduct electricity. If your tent has anodized aluminum poles or fiberglass poles and you’re pitched in a good spot, staying in your tent may be your best option.
If you’re climbing, you’re in a tough spot. The best option is to go down. If this isn’t possible and you have to wait it out on the wall, try to find a good ledge or a cave you can take shelter on or hide in. Space out as best you can from your climbing partners. If you get stuck at a hanging belay, have some people lower down so your group is as spaced out as possible. Bolts and chains will attract/conduct electricity, but your anodized aluminum carabiners won’t (provided the coating isn’t worn off). It’s important to remember, however, that everything conducts electricity when it’s wet.
If someone gets struck by lightning, there are three major risks: electrical shock, secondary heat production, and explosive force. Electrical shock and skin burns are the most common injuries sustained after a lightning strike. Send for help immediately, treat for shock right away, make sure the victim is breathing and has a strong pulse, administer chest compressions and rescue breathing if necessary, and then treat any burns. Make sure to minimize additional lightning risk while treating victims.
Remember: the easiest and most effective way to stay safe in a lightning/thunderstorm is not to get caught in one. Be alert to signs in the weather that will tell you a thunderstorm is coming. If you do get caught, assess your situation. How far are you from safety? How severe is the storm? Can you go down? Should you stay put? In high alpine terrain, speed is safety. Early starts help you get off the mountain or out of the danger zone before a storm hits. Having a good base of fitness, whether hiking, climbing, or paddling, will help you be able to step on the gas and get out of a bad spot if a storm moves in on your fun.