Transcript Hurricanes

Hurricanes
•Tropical Depression: a low-pressure
system of clouds and thunderstorms
with a defined surface circulation and
maximum wind speeds of 38 mi/hr.
•Tropical Storm: a low-pressure system
that starts near the equator and has winds
that blow at between 39-73 mi/hr.
Hurricane: a tropical low-pressure system
with winds blowing at speeds of 74 mi/hr or
more.
Can also be called typhoons or cyclones
when formed over the Pacific or Indian
Ocean.
Formation of Hurricanes
 In Eastern US hurricanes strike between August
and October (water temps must be (80 degrees
F or more)
– Energy from warm water is needed for a lowpressure center to build into a tropical storm then into
a hurricane.
Formation of Hurricanes
In Eastern U.S. strike between August and October
(water temps must be 80 degrees F or more)
-Energy from warm water is needed for a lowpressure center to build into a tropical storm then turn
into a hurricane.
1. Warm ocean water provides energy for the
hurricane.
2. Winds coming together force air upward
3. Winds flow outward above the storm
4. Humid air rising makes the clouds of the storm.
5. Light winds outside the hurricane steer it and let
it grow.
MOVEMENT OF A HURRICANE
 Move westward with tradewinds.
 Near land will move north, south or back
east.
 As long as above warm water can grow
bigger and more powerful.
 A hurricane loses energy as it hits land
because it is cooler and cant get the humid
air from the warm water.
 Eye: center of
hurricane that is clear
and calm because air is
moving downward.
 Eyewall: surrounds the
eye air moves quickly
and upward. Forms tall
ring of cumulonimbus
clouds. Heavy rains
and high winds
Parts of a
Hurricane
Effects of Hurricanes






Huge coastal waves
Strong winds
Heavy rains
Produce tornadoes
Flooding
Storm surge: pushes
a huge mass of ocean
water
Shallow-Water Coastline
Deep-Water Coastline
A storm formed near the equator
with winds at least 65 mi/hr is a:
25%
25%
25%
25%
1.
2.
3.
4.
Tropical Depression
Tropical Storm
Hurricane
Tornado
Which of the following is NOT the
same as a hurricane?
1.
2.
3.
4.
Typhoon
Hurricane
Cyclone
Tropical Storm
25%
1
25%
25%
2
3
25%
4
Which of the following statements is
NOT true about hurricanes?
1. They are a lowpressure system
2. They move eastward
with the Tradewinds
3. Lose energy when
they hit land
4. Have winds of at
least 120 mi/hr
25%
25%
25%
25%
1
2
3
4
As long as hurricanes are ______
they will continue to grow bigger and
stronger.
1.
2.
3.
4.
Above warm water
High pressure
Traveling east
Over dry land
25%
25%
25%
25%
1
2
3
4
The ocean water must be at least
_______ for a hurricane to form.
1.
2.
3.
4.
70º
75º
80º
85º
25%
25%
25%
25%
1
2
3
4
Why do hurricanes lose energy
when they hit land?
1. Because there is
higher pressure
2. Because there is
lower pressure
3. Because it is warmer
4. Because it is cooler
25%
1
25%
25%
2
3
25%
4
This is where we find the heaviest
rains and strongest winds.
25%
25%
25%
25%
1.
2.
3.
4.
Western side of the storm
Eastern side of the storm
The eye of the storm
The eyewall of the storm
Why is the eye of the storm clear
and calm?
1. Because the air is
moving downward
2. Because the air is
moving upward
3. The eye is not
calm
4. Because this is a
low pressure
storm
25%
25%
25%
25%
1
2
3
4
When the air is moving quickly
upward, creating cumulonimbus
clouds that produce the strongest
winds and rain, this is the…
25%
1.
2.
3.
4.
25%
25%
2
3
25%
Eye
Eyewall
Stormwall
Tropical Storm
1
4
True or False?
Hurricanes can produce tornadoes.
1. True
2. False
50%
50%
1
2
______________ pushes a huge
mass of ocean water.
1. Eye
25%
2. Eyewall
25%
3. Storm surge
25%
4. Cumulonimbus clouds
25%