Natural Disasters - Thunderstorms

Thunderstorms (Lightning) 

The feature that characterizes a thunderstorm is lightning.  Because lightning creates thunder, when a storm produces lightning it is called a thunderstorm.  While thunderstorms are very ordinary and affect numerous people each year, it is important to remember that every storm is dangerous.  Although all thunderstorms generate lightning and they may also have associated tornadoes, high winds, hail and flash flooding.

What to do before a thunderstorm

1.  Know these important terms:

• Severe Thunderstorm Watch – A severe thunderstorm is possible.  Remain alert to weather conditions and tune in to a radio or television station for more information.

• Severe Thunderstorm Watch Warning – Severe weather has been sighted or revealed by weather radar.  Anyone or anything in the path of the storm is in danger.

2.  Learn these facts about thunderstorms:

• Thunderstorms can happen individually, in clusters or in lines.

• Usually a thunderstorm yields intense rain for about 30 minutes to an hour.

• Thunderstorms often develop in warm, humid conditions.

• A thunderstorm is about 15 miles in diameter and goes on for about 30 minutes.

• About 10 percent of thunderstorms in the U.S. are considered severe

• To be deemed severe, a thunderstorm must have hail measuring at least three-quarters of an inch in diameter, have winds of at least 58 miles per hour or produce a tornado.

3.  To determine how far away a thunderstorm is you should count the seconds between a flash of lightning and the subsequent clap of thunder.  If you divide this number by five, the result will be distance to the lightning, in miles.

4.  In your yard, clear away dead trees and branches that could fall to cause injury or damage during a thunderstorm.

5.  Fasten down outdoor objects that could blow away or cause damage.  Secure outside doors, shutter windows and close window blinds, shades or curtains.

Lightning

Lightning is caused by a buildup and discharge of electrical energy between positively and negatively charged areas.  Because lightning is unpredictable, there is high risk to both people and property.  Most people who are struck by lightning survive, but experience a variety of long-term symptoms.  Therefore, if there are thunderstorms (lightning) in your area, move inside a building or hard-top vehicle and stay away from metallic objects or fixtures.

1.  If you are inside a building:

• Do not shower or bathe; plumbing fixtures can conduct electricity.

• Do not use a corded phone unless it is an emergency and you have no other option.

• Unplug appliances and computers and turn off air conditioners to avoid power surges.

• Use a battery operated radio for listen for information.

2.  If you are outside:

• In a wooded area, look for protection in a low hollow under a dense cluster of small trees.

• In an open area, move to a ravine or valley; but stay alert for flash flooding.

• Do not stand under anything that will attract lightning, such as a large, isolated tree.

• Do not remain on a hilltop, in a field or in a boat on water.

• Stay away from solitary sheds or other small buildings that are in open areas.

• Move away from open water, get to land and seek shelter.

• Keep away from anything metal.

• Get away from metallic paths (i.e. fences, clotheslines, rails) that could transmit the lightning to you from a distance away.

• If you feel your hair stand on end, that is a sign that lightning is going to strike.  You should squat near the ground on the balls of your feet, put your hands over your ears and your head between your knees.  Make yourself a small target and minimize your contact with the ground.  Do not lie flat on the ground.

3.  Keep in mind these lightning facts and safety tips:

• Often times lightning strikes as far as 10 miles outside of heavy rainfall.

• Victims who have been struck by lightning do not carry electrical charge and can be attended to right away with proper first aid procedures.

• Although “heat lightning” is caused by a distant storm (far enough away that you cannot hear the thunder), you should be aware that the storm may be moving in your direction.

• People are most often injured or killed from lightning during the summertime, in the late afternoon and evening.

• Delay outside activities if thunderstorms are possible.

• Follow the 30/30 lightning safety rule – Move inside if you see lightning and cannot count to 30 before hearing thunder.  Then, stay inside for 30 minutes after hearing the last thunder clap.

• Remember that rubber-soled shoes and rubber tires are not going to provide protection from lightning.  A hard topped vehicle is safer.

(Source: Federal Emergency Management Agency. Are You Ready? A Guide to Citizen Preparedness.)

 

For More Information, Please Visit

• Federal Emergency Management Agency

• Illinois Emergency Management Agency

• National Weather Service

• American Red Cross

• National Severe Storms Laboratory     

Other Natural Disasters

• Floods

• Tornadoes

• Thunderstorms

• Winter Weather

• Extreme Heat

• Fire

• Earthquake

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