What is a thunderstorm A thunderstorm is a

What is a thunderstorm? A thunderstorm is a storm with lightning and thunder. Its produced by a cumulonimbus cloud, usually producing gusty winds, heavy rain and sometimes hail.

Formation of a Thunderstorm � � � For a thunderstorm to form you need moisture, unstable air, and lift. Unstable air is relatively warm and rises quickly. When the rising air reaches its dew point the moisture condenses and creates clouds.

Thunderstorms � � Thunderstorms usually occur along cold fronts as the warm air is forced upward by the advancing cold air. Thunderstorms happen year round but occur most often during the spring and the summer.

Thunderstorms � � All thunderstorms produce lightning. Thunderstorms kill more people than tornadoes each year due to lightning strikes.

Lightning � � � Lightning is a bright flash of electricity produced by a thunderstorm. If you hear the sound of thunder, then you are in danger from lightning. 75 -100 people are struck by lightning each year.

Lightning � Lightning is produced when a negative charge builds up in a cloud and is discharged to the Earth’s surface.

Thunder � � Thunder is caused by lightning. Lightning creates superheated air. As this air is rapidly heated it expands creating the thunderclap that we hear.

HOW FAR IS IT? � � � You can tell how far away lightning has struck by listening to the thunder. When you see lightning, count how many seconds are between the lightning and the thunder. Divide the seconds by 5 and you have how many miles away it is.

HAIL � � � Hail is created when water droplets freeze and fall, but are then caught in an updraft. The ice then rises and more water freezes on it. This process continues until the ice is too heavy to be lifted again.

Hail

Updraft � UPDRAFT - A warm column of air that rises within a cloud. If the air is sufficiently moist, then the moisture condenses to become a cumulus cloud.

Downdraft � A sudden descent of cool or cold air to the ground, usually with precipitation, and associated with a thunderstorm or shower.

Watch vs Warning � SEVERE THUNDERSTORM WATCH - A severe thunderstorm is likely to develop in your area. SEVERE THUNDERSTORM WARNING - A severe thunderstorm is taking place in your area.

SAFETY FOR OUTDOORS � � Keep an eye at the sky. Look for darkening skies, flashes of lightning, or increasing winds. Lightning often proceeds rain, so don’t wait for the rain to begin. If you hear the sound of thunder, go to a safe place immediately.

SAFETY FOR OUTDOORS � � � The best place to go is a sturdy building or a car, but make sure the windows in the car are shut. Avoid sheds, picnic areas, baseball dugouts and bleachers. If there is no shelter around you, stay away from trees. Stay away from water and anything metal.

SAFETY FOR INDOORS � � � Stay away from water!! Do not use corded phones or computers. Stay away from windows and doors!!

HE’S BEEN STRUCK!!!!! � � If someone is struck by lightning call 911. You can touch someone after they have been struck, but not while they are being struck.