THUNDERSTORMS!

Every thunderstorm needs: Moisture: to form clouds and rain Unstable air: warm air that can rise quickly Lift: caused by cold fronts, breezes, or the sun’s heat

The Thunderstorm Life Cycle Developing Stage Towering cumulus cloud indicates rising air Usually little if any rain during this stage Lasts about 10 minutes Occasional lightning

The Thunderstorm Life Cycle Mature Stage Most likely time for hail, heavy rain, frequent lightning, strong winds, and tornadoes Storm occasionally has a black or dark green appearance Lasts an average of 10 to 20 minutes but some storms may last much longer

The Thunderstorm Life Cycle End Stage Rainfall decreases Can still produce a burst of strong winds Lightning remains a danger Downdrafts of cool air stop more warm air from rising into the cloud which causes thunderstorms to stop

What causes lightning? Inside cloud, ice pellets and ice crystals are hitting each other They exchange charges (+ and -) Bottom of cloud becomes negatively charged Ground underneath cloud becomes positively charged Charges attract each other and reach toward each other When they touch = shock!

Lightning Facts The energy from one lightning flash could light a 100-watt light bulb for more than 3 months. The channel of air through which lightning passes can be heated to 50,000°F—hotter than the surface of the sun! The rapid heating and cooling of the air near the lightning channel causes a shock wave that results in the sound we know as “thunder.”

Lightning Safety There is no safe place outdoors when a thunderstorm is nearby. Lightning is attracted to the highest point in the area and to materials that easily conduct electricity, such as water, wiring, and metals.

How far away is the lightning? Count the number of seconds between a flash of lightning and the sound of the resulting thunder. Divide this number by 5 to get an estimate of the distance in miles to the lightning strike.