Download Hurricane Notes (ppt)

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?