Engage
View the video clip:
http://www.youtube.com/watch?v=H9VpwmtnOZc
1. What is a hurricane?
2. How does a hurricane form?
3. What conditions must exist for a
hurricane to form?
Explore
Objective: Manipulate wind speed,
latitude, moisture levels, and
temperature to create a hurricane
Procedural Steps
Distribute the Create-a-Cane activity
sheet.
Review the instructions.
Procedural Steps
Locate the website.
http://www.nhc.noaa.gov/HAW2/pdf/canelab.htm
Note: the “
” button for helpful
information.
Explain
1. What type of wind is needed for
a hurricane to form?
Low to medium winds, blowing in the
same direction (weak wind shear).
2. What is wind shear?
Any change in wind speed or direction.
When the upper-level, mid-level, and lowlevel winds are matched (either light to
medium) this variable is maximized in terms
of hurricane formation.
http://www.noaanews.noaa.gov/stories/images/verticalshear.jp
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3. What is the range of latitudes in
which a hurricane forms?
5-30 degrees North in the ocean and from
the equator.
http://uemap.com/image/english/world/atlantic.gif
4. What must the ocean surface
temperature be for hurricane
formation?
26.5º C (> 80ºF). Also, this warm water
must extend down in the ocean about 50
meters (~150 feet).
http://www.wpclipart.com/science/thermometer_medium.pn
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5. What must the moisture of the lower
and middle atmospheric layer be like
to form?
It must be very moist in the low and middle
levels. The upper layer of the atmosphere
may be either dry or moist.
6. Explain how the sea temperature and
the atmospheric layers are related in
the formation of a hurricane.
The oceans must heat up (26.5º C in this
simulation). The heating of the ocean
causes water (moisture) to escape into the
atmosphere and form clouds. Another
favorable variable occurs when the vertical
wind shear is low or medium.
http://www.weatherwizkids.com/Hurricane_formation.gif
7. What provides the energy for a
hurricane?
As warm air from the warm water rises,
clouds are formed. As the warm air rises, it
cools and releases energy giving the
hurricane its power.
8. What might cause a hurricane to loose
its energy?
A change in wind shear, traveling over water
of lower temperature, and physical aspects
of the land (buildings, hills etc.) will cause
the hurricane to lose its energy.
9. Explain the evolution of a hurricane.
It begins as a tropical disturbance. If
conditions of moisture, temperature, wind,
and geographic location (latitude) are
favorable , then it graduates to a tropical
depression, a tropical storm, and finally a
hurricane.
10. Why are there no hurricanes in
Alaska?
The temperature of the water is insufficient
to generate hurricanes. Secondly, the
distance from the equator makes this
geographically impossible.
11. Summarize the role that the ocean
plays in the development of a
hurricane weather system?
The ocean must become very warm. This
moisture must create a very moist
atmosphere, which in turn results in cloud
formation. If atmospheric winds are low,
then a counter-clockwise circulation pattern
(due to Corialis Effect) is initiated.
Explain - Vocabulary
Tropical
Disturbance
http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/hurr/stages.rxml
Tropical Disturbance
http://www.filerex.com/screenshots/dart_tropical_islands_vol.1_1.02.2_main_window.jpg
http://blogs.citypages.com/blotter/do_not_disturb_sign.jpg
Explain - Vocabulary
Tropical
Depression
http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/hurr/stages.rxml
http://images.paraorkut.com/img/clipart/images/d/depressed-862.png
http://www.filerex.com/screenshots/dart_tropical_islands_vol.1_1.02.2_main_window.jpg
Tropical Depression
Explain - Vocabulary
Tropical Storm
http://i.telegraph.co.uk/telegraph/multimedia/archive/00800/palm-trees-motorway_800788i.jpg
Explain - Vocabulary
Hurricane
http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/hurr/stages.rxml
Hurricane
Elaborate
Objectives:
1. Track the path of Hurricane Katrina using
latitude and longitude coordinates.
2. Note changes of wind speed as the hurricane
develops.
3. Determine how sea temperatures affect the
hurricane’s strength.
4. Evaluate what happens to hurricanes strength
when it reaches landfall.
Materials
1. Pencil
2. Colored pencils
3. NOAA Hurricane Tracking Map
4. Hurricane Katrina Data Table
5. Lab Activity Handout
Materials
1. Pencil
2. Colored pencils
3. NOAA Hurricane Tracking Map
4. Hurricane Katrina Data Table
5. Lab Activity Handout
1. Based on wind speed, what date and
time did Katrina first become a
hurricane?
August 25, 2005
2. When did the greatest wind speeds
occur?
August 28, 2005 at 6:00 PM
3. Using the data table, what was the
longitude and latitude when Katrina
reached a level 5 category?
Latitude 25.7o N; Longitude 87.7o W
4. Looking at the diagram below, what
were the area sea surface
temperatures like when Katrina
became a category 5 Hurricane?
Sea Surface Temperatures were warmer.
5. If all variables are favorable, how
would increasing sea surface
temperatures affect wind speed and
strength of the storm?
The warmer water and moisture-rich air
would provide more energy; therefore the
wind speed and intensity of the storm
would increase.
6. When did the wind speeds decrease
the fastest?
August 30, 2005
7. As the pressure in Hurricane Katrina
got lower or higher, what happened
to the wind speed?
Wind Speed increased when pressure
was lower and decreased as pressure
became higher.
8. What caused Hurricane Katrina to
slow to a tropical depression on
August 30th?
Moving over cooler water.
9. What happens to the strength of a
hurricane as it moves across land?
Why does this happen?
The hurricane looses strength, begins to
weaken and fall apart. This happens
because the hurricane loses its energy
source (warm ocean waters).
10. What geographical areas of the
United States are prone to being hit
by hurricanes? Why?
Gulf Coast states and the Eastern states of
the United States are at risk for one or more
hurricanes each year. The warmer ocean
waters of the Atlantic Ocean and Gulf Coast
of Mexico provide the fuel for the energy in
the formation of hurricanes.
Evaluate
Complete the evaluation.