Thunderstorms are a common weather occurrence during the spring and summer months. The typical thunderstorm is 15 miles in diameter and lasts an average of 30 minutes. Most storms occur during the afternoon and evening hours but can occur at all hours and at any time of the year.
Despite their small size, ALL thunderstorms are dangerous. Every thunderstorm produces lightning. Heavy rain can lead to flash flooding. Strong winds, hail, and tornadoes are also associated with thunderstorms.
Only about 10 percent of the thunderstorms in the United States are classified as severe. A thunderstorm is severe if it produces hail at least 3/4 inch in diameter, winds of 58 mph or higher, or tornadoes.
Before a storm:
· Know the name of the county or parish you live in. Severe weather warnings are issued on a county or parish basis.
· Watch for signs of approaching storms: Increasing wind, flashes of lightning, the sound of thunder, and static on your AM radio.
· If a storm is approaching, stay informed by listening to NOAA Weather Radio, commercial radio or television.
· Postpone outdoor activities if thunderstorms are imminent.
When thunderstorms approach:
· Move to a sturdy building or hard top automobile with the windows rolled up. Go to an interior room in the building.
· Get out of boats and away from water.
· Move to higher ground if flash flooding or flooding is possible.
· Avoid using telephones or electrical appliances.
· Do not take a bath or shower. Metal pipes can conduct electricity.
If caught outdoors without a nearby shelter:
· Find a low spot away from trees, fences, and poles that is not subject to flooding.
· In a forest, take shelter under the shorter trees.
· If you feel your skin tingle or your hair stand on end, squat low to the ground on the balls of your feet. Place your hands on your knees with your head between them. Make yourself the smallest target possible and minimize your contact with the ground.
To estimate the distance in miles between you and the lightning flash, count the seconds between the lightning and the thunder and divide by five.
Sixteen million thunderstorms occur every year around the world.