Severe Weather

LIGHTNING Ever touched someone after scuffling your feet on the carpet and received a mild shock? When you walk around the friction between the floor and your shoes builds up an electric charge in your body. When you touch someone else, the charge is released. You’ve experienced what lightning is like! https://www.youtube.com/watch?v=LYubHpEMTPM Storm

Lightning is an electric current Lightning is an electric current. Within a thundercloud way up in the sky, many small bits of ice (frozen raindrops) bump into each other as they move around in the air. All of those collisions create an electric charge. After a while, the whole cloud fills up with electrical charges. The positive charges or protons form at the top of the cloud and the negative charges or electrons form at the bottom of the cloud.

Since opposites attract, that causes a positive charge to build up on the ground beneath the cloud. The grounds electrical charge concentrates around anything that sticks up, such as mountains, people, or single trees. The charge coming up from these points eventually connects with a charge reaching down from the clouds and - zap - lightning strikes! https://www.youtube.com/watch?v=6MUYsIjTKvk

HOW LIGHTNING FORMS VIDEO: Lightning can occur between: Two clouds Earth and a cloud Two parts of the same cloud HOW LIGHTNING FORMS VIDEO: https://www.youtube.com/watch?v=h-0gNl5f4BU https://www.youtube.com/watch?v=KO3H285CFRo

TORNADOES Tornadoes happen in only 1% of all thunderstorms. A tornado is a small, spinning column of air that has high wind speeds and low central pressure and that touches the ground. A tornado starts out as a funnel cloud that pokes through the bottom of a cumulonimbus cloud and hangs in the air. The funnel cloud becomes tornado when it makes contact with the Earth’s surface.

75% of the worlds tornadoes occur in the United States 75% of the worlds tornadoes occur in the United States. (Mostly in Tornado Alley). Most happen in early spring and summer when cold, dry air from Canada meets warm, moist air from the Tropics. The size of a tornado’s path is about 5 miles long and about 30 – 200 feet wide. Tornadoes have wind speeds from 75-100 mph and more violent tornadoes spin over 300 mph.

What is this cloud called? It’s a FUNNEL CLOUD Until it touches the ground, Then it’s a TORNADO!

https://www.youtube.com/watch?v=acgduoio7-I

FUJITA SCALE

This is the devastation from a TORNADO.

Hurricanes A large, rotating tropical weather system that has wind speeds of at least 120 km/h (75 mph) is a hurricane. Hurricanes are the most powerful storms on earth. This is an actual satellite photograph. Can you tell which states it is above?

A Hurricane begins as a group of thunderstorms moving over tropical waters. Winds traveling in two different directions meet and cause the storm to spin.

Cross section of a Hurricane

With high winds from 120 km/h (75 mph) to 300 km/h (186 mph) – Hurricanes can knock down trees, destroy buildings and homes. Most hurricane damage is caused by flooding associated with heavy rains and storm surges. A storm surge is a wall of water that crashes into the shore and can be 26 ft high to 100 miles long.

https://video.nationalgeographic.com/video/101-videos/hurricanes-101

Thunderstorms-Tornadoes-Hurricanes DRAW a Venn Diagram Work in groups Thunderstorms-Tornadoes-Hurricanes Compare and Contrast (How are they similar, how are they different from each other) Describe 2-3 facts for each section Thunderstorms