The word “thunderstorm” focuses on the wrong threat: it is the lightning that injures or kills. From first-hand experience, the most frightening aspect of hiking or climbing is the prospect of being caught way out in an open field or way above the tree line in an electrical storm with nowhere to hide. The experience assaults your senses.
The thunder envelopes you with 360° sound and you can feel its bass notes throughout your body. Even before an actual lightning strike, the electricity envelopes you, infuses you, and all the hairs on your body stand on end. Anything metal starts vibrating and giving you shocks. There is a sound I can only describe as somewhere between static and something frying in oil over a hot flame; horror shows sometime use that sound to signal an impending alien monster. If you get caught in the middle of that maelstrom, you will surely learn how you react to a life-threatening emergency. As with all emergencies, panic is the worst reaction.
Preparation
Familiarize yourself with local weather patterns if you intend to hike often. At a minimum, always check the weather forecasts local to the chosen hike. See: Language of Clouds. Hiking in a simple rain squall is no big deal; if you follow the recommended equipment lists, See Short-hike Equipment List and Long-hike Equipment List, you will have the proper cover to continue with your hike.
Knowing When to Turn Around
Turning around may not be your first instinct. It is natural to think: “maybe the storm will pass us by.” The problem is that in the meantime the weather may worsen, and there is often no time to turn back to a haven when all hell breaks loose. It is much better to live for another chance at Mother Nature on another day.
How to React in a Storm
Despite precautions, you may find a time when a lesser rain event turns into a thunderstorm. Do not panic! Panic only causes additional problems like shallow breathing, erratic foot placement, and a greater chance of tripping or pulling a muscle. Move deliberately to avoid tripping and injury.
This is one time to be fatalistic. You cannot hide from lightning, but you can reduce the odds of it striking you. Your basic strategy is to get lower than other things around you. Lightning is an electrical discharge looking for the shortest path to the ground. While never guaranteed, the odds are it will seek metal (a good conductor) and/or the highest object around, even a tree if it is wet. The water on a tree’s bark is a better conductor than the wood of the tree itself.
If you are in or near a forest, seek cover near a cluster of trees rather than a single tree, and a cluster that is thicker and lower than other trees nearby. Likewise, if camping, locate your tent in a thick stand of trees instead of next to an isolated tree or two. Avoid shallow caves: they channel electricity and are dangerous in a storm even though you may think they provide cover.
You do not want to be on a ridge, a summit or a plateau. Never sit or lie down on the ground as these positions facilitate greater ground-body contact, and lightening is seeking a path to ground, especially wet ground. Head for a depression, a valley, a ravine or a gully to get low. Stay away from puddles or any water feature. Water conducts electricity better than rock or dirt.
If you have a dog with you, keep it close to you. Most dogs will want you comforting them as the sound of the thunder is frightening to them.
The 30/30 Rule
The National Weather Service advises following the “30/30 rule.” When you see lightning, count the seconds that pass until you hear thunder and divide by 5. This will give you the number of miles you are from the storm center. If you count 30 seconds or less between lightning and thunder, the storm center is within 6 miles and you should seek shelter immediately. Stay put for 30 minutes after the last lightning flash or rumble of thunder. The National Weather Service estimates that 50% of all lightning deaths are sustained after the storm has passed. Be aware of other thunderstorms that may arise after the initial storm.
If a Lightning Strike is Imminent
If lightning is about to strike you or near you, some signals are that your hair may stand on end, you may feel a tingling in your skin; metal objects may vibrate, and you may hear a crackling sound.
If you detect any of these signals, drop backpacks with frames, hiking sticks and any other metal. Spread 20-30 feet away from others, squat on top of insulating material or on the soles of your boots, with your head down, feet together, and arms wrapped around your legs (for a safer lightning path in case of a strike). That is called the “lightning crouch.”
After a Lightning Strike
If anyone in your group has been struck, they are safe to touch. There is no electric residue. If they are not breathing, start CPR immediately. Check for burns, especially in areas where they might have been wearing metal. Keep them warm and seek help immediately. Now is the time for the red button on the emergency GPS.