THUNDER STORMS AND LIGHTNING By: Kyle Clearly, Zach Weissinger, Nick Reimer
STORM FACTS Nearly 2000 thunderstorms are in progress around the world. A typical thunder storm is 15 miles in diameter and last an average of 30 minutes. There are 16 million thunder storms a year.
FACTS CONTINUED You can estimate how far away a storm is by counting the seconds between flashes of lightning and thunder claps. The strongest type of thunder storm is the super cell.
LIGHTNING FACTS The odds of becoming a lightning victim in the U.S. in any one year is 1 in 700,000. The odds of being struck in your lifetime are 1 in 3,000. Lightning is five times hotter than the surface of the sun.
LIGHTNING FACTS CONTINUED A lightning flash is no more than one inch wide. A stroke of lightning moves 62,000 miles per second, one third the speed of light. Power failures caused by lightning strikes cost utility companies as much as $1 billion annually.
VOCAB Stepped Leader: The difference in positively and negatively break down and a branch channel of partially charged air is formed between the two charged regions. Return Stroke: The stepped leader generally moves from the center of the cloud toward the ground. When it nears the ground a branch channel of positively charged particles rushes upwards to meet it.
VOCAB CONTINUED Super cells: Severe thunderstorms can produce more violent weather conditions that can develop into selfsustaining, extremely powerful storms. Downbursts: Strong winds exceeding speeds of 160 Km/h can cause violent downdrafts that are concentrated in a local area.
HOW THUNDER STORMS ARE FORMED For a thunder storm to form it needs three conditions. 1. A source of moisture. 2. Lifting of the air mass. 3. And an unstable atmosphere. Convention can cause a cumulus to grow into a cumulonimbus cloud. Cumulonimbus clouds conditions are the same that produce thunderstorms.
TYPES OF THUNDERSTORMS Air-mass thunderstorms: When air rises because of unequal heating of Earth s surface within one air mass. There are two kinds of Air-mass storms. Mountain thunderstorm: Air mass rises by orographic lifting which involves air moving up the side of a mountain.
Sea-Breeze thunderstorm: Local air mass thunderstorms that occur because land and water stores release thermal energy differently. Occur along coastal areas in the summer. Frontal Thunderstorm: Produced by advancing cold fronts and more rarely warm fronts. In cold fronts cold air pushes under warm air which is less dense, rapidly lifting it up a steep cold front boundary which produces a thin line of thunderstorms.
LIGHTNING Lightning is the transfer of electricity generated by rapid rushes of air in cumulonimbus clouds. Sheet Lightning: is reflected by the clouds. Spider Lightning: Crawls across sky for up to 150 Km. Ball Lightning: A hovering ball about the size of a pumpkin that fizzles or bangs.
THUNDER A lightning bolt heats the surrounding air to about 30,000 C. The thunder you hear is the sound produced as superheated air rapidly expands and contracts. Sound waves travel faster than light waves, so you hear it before you see it.
SAFETY PRECAUTIONS To avoid being stuck by lightning, squat low to the ground on the balls of your feet. Duck your head and make yourself smallest target. Avoid hiding in Small sheds, isolated trees, and convertible automobiles.
QUESTIONS What is the strongest type of thunder storm? A. Super cell Storm. B. Single cell Storm. C. Multi cell Cluster Storm.
How many times hotter is lightning than the sun? A. 2x hotter. B. The same heat. C. 5x hotter.
What causes thunder? A. Lightning. B. Rain. C. Wind.
How hot is lightning? A. 30,000 F B. 54,000 F C. 75,000 F
What should you do if your caught outside in a thunderstorm? A. Stand in the middle of the field. B. Seek out shelter. C. Hide under a tree.
ANSWERS 1. A 2. C 3. A 4. B 5. B http://www.youtube.com/watch?v=w3qaavpzeda