SEVERE WEATHER

The Water Cycle is the driving force behind all severe weather

Thunderstorms Large storms with strong winds, thunder and

lightning. These are produced by cumulonimbus clouds.

Lightning Areas of positive and negative electrical

charges build up in a cloud A sudden energy discharge between two areas Can happen from cloud to ground, cloud to

cloud or ground to cloud

Thunder This happens when lightning occurs

Lightning heats the air to 35,000 degrees Fahrenheit

This causes the air to expand rapidly, causing a “sonic boom”

Tornadoes

These are produced by cumulonimbus clouds

Usually occur when a warm, humid air mass collides with a cool, dry air mass (cold front)

Hypothesis - Horizontal spinning turns vertical.

http://www.msnbc.msn.com/id/9007188/ns/weather-weather_news/t/birth-tornado/

Hurricanes Hurricanes begin as a tropical depression

Low pressure area (over warm tropical waters)

As it grows in size it becomes a tropical storm

If it increases in size and strength it becomes a hurricane Once the winds reach 75 mph it becomes a

hurricane

Hurricanes get their energy from the warm, humid air at the water’s surface rising and condensing

What causes hurricanes to move westerly toward the US East Coast?

TRADE WINDS

What direction do hurricanes rotate? COUN TERCLOCKWISE

What are natural ways hurricanes are altered (buffered)?

BARRIER ISLANDS AND WETLANDS