Download hurricane - Lisle CUSD 202

Hurricanes
What is a hurricane??
• hurricane- a large rotating storm of tropical
origin that has sustained winds of at least
119km per hour
• cyclone-A system of winds rotating inward to
an area of low atmospheric pressure, with a
counterclockwise (northern hemisphere) or
clockwise (southern hemisphere) circulation; a
depression
How to make a hurricane
• In developing tropical cyclones, strong thunderstorms
occur. Air pressure drops at the surface of these
storms. This low pressure attracts warm moist air from
the ocean's surface. The Coriolis force causes the
resulting low-level winds to spiral in a ounter clockwise
direction around the center of the low in the Northern
Hemisphere. (Winds swirl clockwise in the Southern
Hemisphere.)
• Typically, an "eye" forms when the tropical cyclone
reaches hurricane strength, but an eye is not necessary
for a tropical cyclone to become a hurricane.
FUN FACTS
• Once they have formed, they travel away from
the equator, remaining over warm water as they
grow in intensity.
• As they reach land or cool water, hurricanes
dissipate.
• Hurricanes are the most powerful of all storms.
• Hurricanes form over tropical seas that have sea
surface temperatures above 27° Celsius.
• They do not form at the equator because at 0°
latitude the Coriolis Effect does not provide
enough spin to initiate hurricane conditions
Parts of a hurricane
• The eye is a region of mostly calm weather found at the
center of strong tropical cyclones. The eye of a storm is a
roughly circular area and typically 30–65 km (20–40 miles) in
diameter
• Eye wall This is the location within a hurricane
where the most damaging winds and intense
rainfall is found
• A rainband is a cloud and precipitation
structure associated with an area of rainfall
which is significantly elongated
Looking for a hurricane
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1. New Orleans, Louisiana
2. Lake Okeechobee, Florida
3. Florida Keys
4. Coastal Mississippi
5. Miami/Ft. Lauderdale, Florida
6. Galveston/Houston, Texas
7. Cape Hatteras, North Carolina
8. Eastern Long Island, New York
9. Wilmington, North Carolina
10. Tampa/St. Petersburg, Florida
Watch or Warning??
• HURRICANE WATCH
An announcement that hurricane conditions (sustained
winds of 74 mph or higher) are possible within the specified
coastal area. Because hurricane preparedness activities
become difficult once winds reach tropical storm force, the
hurricane watch is issued 48 hours in advance of the
anticipated onset of tropical-storm-force winds.
• HURRICANE WARNING
An announcement that hurricane conditions (sustained
winds of 74 mph or higher) are expected somewhere within
the specified coastal area. Because hurricane preparedness
activities become difficult once winds reach tropical storm
force, the hurricane warning is issued 36 hours in advance
of the anticipated onset of tropical-storm-force winds.
Watch This
Hurricane vs. typhoon
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Category 3
Quiz
1. What is the eye wall?
A. The eye wall is the ring and heavy showers and
thunderstorms.
B. Where everything gathers and disappears into
space.
C. The calm part of the hurricane.
Quiz
2. What is the eye of a hurricane?
A. The eye of a hurricane is small area of clear
weather.
B. Where the hurricane meets the ground.
C. The roughest part of the hurricane.
Quiz
3. What are the outer bands of a hurricane?
A. The outer bands are a term given to the showers
and thunderstorms.
B. The wind walls that make up the hurricane.
C. Dry parts of the hurricane.
Quiz
4. Which region is not common to have a
hurricane?
A. Gulf of Mexico
B. Western Caribbean
C. Panama
D. Cape Verde Islands
Quiz
5. Which of these effects is not true about a
hurricane?
A. Heavy rain
B. High winds
C. Flooding
D. Fires