LIGHTNING

Thunderstorms develop most often on hot, humid days when warm moist air rises quickly to great heights (25,000-30,000 feet) forming dark clouds with static electricity. The top and bottom of the clouds, often called thunderheads, develop opposite charges. When the difference in charge reaches a level where the air can no longer insulate, lightning reaches out to equalize the difference. A lightning bolt can contain as much as 200 million volts and 300,000 amperes, with a temperature as high as 8,000 C. A bolt can reach out over a mile in front of a storm through a channel only 8 cm wide.

Lightning is most likely to strike the tallest or highest object around. This can include tent poles, walking sticks, frame packs and bicycles. Thunderstorms are most dangerous as they approach an area within 1 mile. Distance can be calculated by counting the seconds between the flash and the rumble - 5 seconds equals 1 mile.

Don'ts:

• Don't be the highest object in the area. Avoid or get off of mountain tops & summits, ridges and cliff tops. Avoid tall trees, poles, and large boulders.  Move out of open areas, fields, and meadows where you are the highest object.
• Stay away from the highest object and metal objects.
• Stay away from gullies, washes, and low places that collect water.
• If on or near water, get off and move away from the shore
• Don't sit under underhangs
• Avoid shallow caves
• Avoid places that have been hit by lightning before

What to do if caught out:

• Get off the mountain top or summit and below tree line if possible. Once below tree line find a low spot among small trees.
• If you can't get below tree line, get as low as possible by sitting down. Sit on your pack,ensolite pad or rope coil with your knees flexed; hug your knees to keep your feet together to minimize the ground effect of a near-by strike.
• Thick growths of small trees are your best bet. The group should separate but stay within eye of each other.