With the summer heat comes the threat of thunderstorms and even severe ones called derechos - a wide spread, long lived wind storm that can bring about destruction like tornadoes. For a hiker its crucial to find out forecasts, even long range, and prepare for an outbreak. F the threat of dangerous storms by seeking shelter, preferably in a strong building. Get off exposed ridge tops and head below tree line well before a storm approaches. Be sure your tent is not pitched in a low lying area or beside a stream that may be proned to flash flooding (which is very dangerous). When setting up your tent, check the ground first to see if there has been ponding of water there. If you know there will be a violent outbreak of storms, get off the trail. Always carry maps, a guidebook, and a charged phone so you can make emergency arrangements.
Here are some other facts about lightning and safety measures, taken from the website HikingAbout.com
Facts About Lightning• The National Weather Service estimates your chances of getting hit by lightning in a given year are literally one-in-a-million. But over the course of a lifetime those odds drop to one-in-10,000.
• Lightning reaches temperatures of 50,000 degrees Fahrenheit—five times hotter than the sun.
• A bolt of lightning can reach five miles in length, then spread across a 60-foot area from its point of contact with the ground.
• Some forms of lightning can strike at great distances either in advance or behind the center of a thunderstorm—anywhere from five to 10 miles away. That means that people sometimes believe that they are at a safe distance when they are actually well-within range of lightning activity.
• Lightning is more common in spring and summer but can occur at any time of year and anywhere in the country.
- Check forecasts. Use Weather.Com or a reliable forecasting site to get predictions on conditions for the area where you will be hiking.
- Hike earlier in the day. Thunderstorms are much more likely to develop during the afternoon, especially in mountainous areas. So if you’re planning a hike at higher elevations, try to be off of the trail before noon.
- Stay vigilant. Look for cloud masses that begin to grow quickly and darken. Anvil-shaped clouds are a sign of potential thunderstorm activity. Watch the direction that clouds are moving and listen for any hints of approaching thunder. Increasing winds are also an indication of an approaching storm.
- Follow the 30/30 Rule. Count the time between a lightning flash and the sound of thunder. Sound travels roughly one mile in five seconds. If the time between the lightning and thunder is less than 30 seconds, that means you’re well within the danger zone and need to find a safe spot.
- Watch out for danger signs. If your hair begins to stand up or your skin tingles, those are both indicators of imminent lightning danger.
How to Protect Yourself
- Avoid exposed areas. Ridgelines, open fields, lone trees or isolated groves, and tall, prominent outcroppings all increase your risk of being hit by lightning. But sheds, picnic shelters, and the mouths of caves are also dangerous choices.
- Stay away from conductors of electricity. Avoid water (at least 100 yards away) and stay clear of metal objects, such as fences. If your day pack, trekking poles, or any other personal items have metal in them, move that gear 100 feet or more from where you will be.
- Find a low protected area. You’ll want to locate a swale or low-lying spot but be careful not to take cover in an arroyo or creek bed where flash floods may get channeled.
- Make yourself a small target. If you’re caught in a storm with lightning nearby, get into a crouching position with your head tucked and hands covering your ears.
- Spread your group out. While you and your fellow hikers will feel a natural tendency to stay closely together, by remaining in a cluster, you create a bigger target.
- Do not lie flat. Your goal is to minimize contact with the ground and the surface area of your body that's exposed to lightning.
- Wait 30 minutes. To avoid lightning that may strike behind the storm, wait 30 minutes after you’ve heard the last thunder before leaving your safe area.