Hurricane Formation and Impact

Hurricane Formation and Impact

Hurricanes: Destructive Storms

Hurricanes are among the earth's most destructive natural disasters. How do they form? What are their behaviors? How powerful are hurricanes?

Multiple Choice

Where are hurricanes formed?

• Cool, arctic waters

• Warm, dry land

• Cool, moist land

• Warm, tropical waters

Ingredients for a Hurricane

• Hurricanes form in tropical regions with warm water and warm, moist air.

• When tropical waters are heated to about 80F (27C) at the surface AND to a depth of 150 feet, a hurricane can form.

• Hurricanes also need a cool atmosphere, a still ocean surface, and a distance of at least 300 miles from the equator.

• Hurricanes can't just form anywhere...

Multiple Select

What is needed for a hurricane to form? Check all that apply...

• Warm water

• A still ocean

• A hot atmosphere

• Cold water

• Distance of 300 miles from equator

How Do Hurricanes Form?

• The very warm surface water evaporates and water vapor rises.

• The water vapor condenses to form storm clouds and raindrops.

• The condensation process releases a great deal of heat.

• Water warming, evaporating, condensing, and releasing heat builds clouds and a core of low pressure.

Look closely at this storm...

• Can you identify the eye of the storm?

• In which direction is the hurricane spiraling?

Multiple Choice

Which way is this storm spinning?

• Clockwise

• Counterclockwise

The Movement of a Hurricane

Northern Hemisphere = counterclockwise
Southern Hemisphere = clockwise

Earth's rotation helps with the spinning of a storm and east-to-west winds help send the storm across the ocean

Parts of a Hurricane

• The calm, low pressure center is called the "eye"

• The area on the outside of the eye is the "eye wall"

• "Feeder bands," or rain bands, are the outermost winds and rain.

Multiple Choice

True or False: Hurricanes cause more damage than any other kind of storm on Earth.

• True

• False

FACT

Scientists estimate that the heat energy thrown off every 20 minutes by a single hurricane is equivalent to the energy released by the explosion of a 10-megatron nuclear bomb.

Storm Surge

• As a hurricane strikes land (landfall) is pushes ahead of itself a hill of ocean water as high as 15 feet and 100 miles wide.

• This hill of ocean water is called storm surge. 

• Rains worsen flooding near the shore.

Multiple Choice

True or false: Storm surge and flooding cause over 90% of hurricane deaths.

• True

• False

Hurricane Katrina

• Storm Surge of 22-26 feet high

• The costliest storm to strike the U.S. causing nearly 2,000 deaths and $80 billion in property losses

Multiple Choice

REVIEW: When a hurricane makes landfall, what is the greatest danger to residents?

• Heavy rain

• High wind speed

• Storm surge

• Low pressure

Multiple Choice

REVIEW: Around what temperature does the water have to be at for a hurricane to form?

• 60 degress F

• 70 degrees F

• 80 degrees F

• 90 degrees F

Multiple Choice

REVIEW: What is the innermost part of a hurricane (the area that is the calmest)?

• The eye wall

• The eye

• Rain bands

• Convection spiral