Hurricanes

What is a hurricane?Hurricanes are tropical cyclones.

They form in the southern Atlantic Ocean, Caribbean, Gulf of Mexico, and eastern Pacific Ocean.

Their winds spiral outward in a counterclockwise, circulation pattern.

What conditions must exist for a hurricane to form?

Low to medium winds blowing in the same direction

5–30 degrees north of the equator in the ocean

Ocean surface temperature of greater than 80 F that extends down to about 150 feet deep (50 m)

Lower atmosphere must be moist

How do hurricanes form?The air mass above the tropical waters

takes on the temperature and humidity of the water beneath it.

Incoming winds force the air upward.The warm, moist air rises, forming water

vapor and clouds. Above the storm, the winds flow outward.Outside winds blow inward, and the cycle

repeats.

How do hurricanes move?

Hurricanes turn to the right, away from the equator, because of the Coriolis Effect caused by Earth’s rotation.

You will learn about this phenomenon later in the lesson.

Where does the energy for a hurricane originate?

The Sun heats the oceans.

Warm air rises, and as it cools, it releases energy, fueling the hurricane.

Why don’t hurricanes form in higher latitudes?

The temperature of the oceans is not warm enough.

The distance is too far from the equator.

Hurricane Katrina

Reflective Question

How do oceans play a role in the development of weather systems including hurricanes?