Thunderstorms & Lightning

Related Information Hurricanes Thunderstorms & Lightning Tornadoes

All Thunderstorms Are Dangerous

The ingredient that defines a thunderstorm is lightning. The unpredictability of lightning increases the risk to individuals and property. In the United States an average of 300 people are injured and 80 people are killed each year by lightning. Although most lightning victims survive, people struck by lightning often report a variety of long-term debilitating symptoms, including memory loss, attention deficits, sleep disorders, numbness, dizziness, stiffness in joints, fatigue, depression, and muscle spasms.

Thunderstorm Facts...

• Thunderstorms typically produce heavy rain for a brief period, anywhere from 30 minutes to an hour.
• Every thunderstorm produces lightning.
• Warm, humid conditions are very favorable for thunderstorm development.
• Other associated dangers of thunderstorms include tornadoes, strong winds, hail, and flash flooding.
• If you can hear thunder, you are close enough to the storm to be struck by lightning. Go to safe shelter immediately!
• Lightning strike victims carry no electrical charge and should be attended to immediately. If breathing has stopped, begin mouth-to mouth resuscitation and if the heart has stopped, administer CPR if you've received CPR training.
• Know the calculation to determine how close you are to a thunderstorm: Count the number of seconds between a flash of lightning and the next clap of thunder. Divide this number by 5 to determine the distance to the lightning in miles.

Understanding Weather Reports & Alerts...

A thunderstorm is classified as severe if it (i) produces hail at least 3/4 of an inch in diameter, (ii) has winds of 58 miles per hour or higher, or (iii) produces a tornado.

Severe Thunderstorm Watch:

Severe Thunderstorm Warning:

When Thunderstorms Threaten Your Area...

If You're Inside A Home:

• Secure outdoor objects that could blow away or cause damage.
• Close window blinds, shades and curtains.
• Avoid taking a shower or bathing. Plumbing and bathroom fixtures can conduct electricity.
• Avoid using corded telephones (except in an emergency). Cordless and cell phones are safe to use.
• Unplug appliances and other electrical items such as computers and turn off air conditioners. Power surges from lightning can cause serious damage.

IF YOU'RE OUTSIDE, WITH NO TIME TO REACH A SAFE LOCATION:

• In a forest, seek shelter in a low area under a thick growth of small trees.
• In open areas, go to a low place such as a ravine or valley but be alert for flash floods.
• Do not stand under a natural lightning rod, such as a tall, isolated tree in an open area.
• Do not stand on a hilltop, in an open field, on the beach or in a boat on the water.
• Avoid isolated sheds or other small structures in open areas.
• Get away from open water. If you're boating or swimming, get to land and find shelter immediately.
• Get away from anything metal-motorcycles, golf carts, golf clubs and bicycles.
• Stay away from wire fences, clotheslines, metal pipes, rails and other metallic paths that could carry lightning to you from some distance away.
• Do not lie flat on the ground. Instead, squat low to the ground on the balls of your feet. Place your hands over your ears and your head between your knees. Make yourself the smallest target possible and minimize your contact with the ground.

Your Chances Of Being Struck By Lightning Are About 1 In 600,000 But Could Be Even Less By Following These Safety Tips:

• Postpone outdoor activities if thunderstorms are likely;
• Remember that rubber-soled DO NOT provide protection from lightning; and
• Use the 30/30 lightning safety rule -- Go indoors if after you see lightning, you cannot count to 30 before hearing thunder. Stay indoors for 30 minutes after hearing the last clap of thunder.

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