Essay Assignment
Name __________________
This will be an essay, like you write in English Language Arts. You need the same elements in this essay, including an
introduction with a thesis statement, several paragraphs for individual points, and a concluding paragraph. It will be
about 2 pages, typed, double-spaced.
The Topic: Compare and contrast the formation of hurricanes and tornados.
Brainstorming:
Topic
Where do they form?
Hurricanes
 E Atlantic or W Pacific
 Warm water
 Tropics
What are they?



What conditions do you have
to have before it can form?



What causes it to spin?

Rotating cluster of thunderstorms
Swirling collaboration of storms with very
powerful winds
Destructive swirling columns of air that
form over water
A cluster of thunderstorms
Ocean water temperature above 82⁰F
Low vertical wind shear so as not to
spread out the latent heat from
condensation
Coriolis Force due to rotation of the Earth
Tornados
 Tornado Alley (where warm moist
air from Gulf of Mexico, Warm dry
air from the SW, and cold dry air
from the Rockies (N) meet)
 Mid-western US
 Australia
 A violent column of swirling,
rotating air that descends from a
supercell thunderstorm


A super-cell thunderstorm
Warm moist air trapped under
hot dry air trapped under cold
dry air

Warm and cold air try to mix, but
they can’t because of the hot dry
air in the middle
Warm, moist air is less dense, so it
tries to rise
Cold, dry air is more dense so it
tries to sink
The layers are trapped and cannot
mix
Instability of the air and difference
of air density, pressure, and
temperature
Energy from previous
thunderstorms



What fuels it?



How do differences in air
temperature/density/pressure
contribute to the formation of
it?


Warm water that is warm to a sufficient
depth (82 ⁰F)
Cluster of thunderstorms
Low vertical wind shear, increasing the
concentration of the latent heat

Warm, less dense air from the surface
rises until it cools and condenses
Cool, dense air spreads outward and then
sinks and falls back to the ocean surface


Warm air is less dense than cold
air. Warm air molecules are
moving faster (temperature is a
measure of the speed of


Cool, dense air rushes in to take the place
of the rising hot air, is reheated, and
rises again
Convection cells gather in a circle, with
the region of lowest pressure/highest
temperature in the eye



particles), so there is more space
in between them.
Warm air, which is less dense,
rises. Cool air, which is more
dense, falls.
Warm air rising causes areas of
low pressure. Cool air sinking
causes areas of high pressure.
The attempt of the different
density airs to rise or fall is what
starts the horizontal rotation of
the tornado.
Outline:
Now you have to decide if you are going to write it grouped by category (alternating between hurricanes and tornados)
or by topic (air pressure and density for both hurricanes and tornados, then fuel for both ….)
Which did you choose? ______________________________________
Now you need to make an outline. I’ve started it for you.
I.
Introduction
a. Hurricanes and tornados are both destructive products born from intense thunderstorms
b. Hurricanes and tornados are both essentially swirling columns of air
c. It can be easy to confuse the two types of storms unless you understand what causes and drives them
d. There are some similarities between the formation of the two storm types, such as:
i. Needing warmth for fuel
ii. Cold, dense air falling while warm, less dense air rising
iii. Differences in humidity between air layers
e. There are also some difference between the formation of the two storm types, such as:
i. Location
ii. What causes and drives the rotation of the storm
iii. The presence of convection currents
1. The formation of an eye
f. Thesis: _There are both similarities and differences between the formation and progression of both
hurricanes and tornados. They are similar in …, but they have major differences in …
II.
Topic #1: What are they?
a.
Similarities
i. Hurricanes and Tornados
1.
2.
3.
b. Differences
i. Hurricanes and Tornados
1.
2.
3.