What Is A Storm? • A storm is a violent disturbance in the atmosphere.
Thunderstorms • Thunderstorms are heavy rainstorms with thunder and lightning.
Lightning • During a thunderstorm, positive and negative charges build up. • Lightning is a sudden spark, or discharge, of these charges in one of 3 ways: • Within one cloud • From cloud to cloud • From cloud to ground
Tornadoes • A tornado is a rapidly whirling, funnel-shaped cloud that reaches down from a storm cloud to touch Earth’s surface.
How Tornadoes Form • Tornadoes develop in low, heavy, cumulonimbus clouds – the same clouds that bring thunderstorms. • Most likely to occur in spring and early summer, usually found in the middle of the U.S.
Hurricanes • A hurricane is a tropical storm with winds of 119 km/h or higher. • In the Pacific ocean, hurricanes are called typhoons.
How Hurricanes Form • A hurricane begins over warm water as a low-pressure area, or tropical disturbance. • If it grows in size and strength, it will become a tropical storm, which may then become a hurricane.
How Hurricanes Form • A hurricane gets its energy from warm, humid air. • The southern Atlantic Ocean and the Gulf of Mexico provide the heat and moisture needed to feed a very large hurricane.
The Eye of the Hurricane • The center of the hurricane is a ring of clouds surrounding a quiet “eye.” • The winds get stronger as you get closer to the eye, but once you are in the eye, it calms down suddenly.
Hurricane Damage • One of the most dangerous features of a hurricane is the storm surge. • A storm surge is a “dome” of water that sweeps across the coast where the hurricane lands.
Lake-Effect Snow • When a continental polar air mass (cold and dry) crosses a body of water, it picks up moisture and gets a bit warmer. • This warm air rises, cools, condenses, and falls back down as snow.