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We need to know the differences and similarities between
land storms (tornadoes) and ocean storms (hurricanes.) Both
kinds of storms originate over heated surfaces and blow
toward a low pressure center.

The hurricane originates over warm water and has a path width
of hundreds of miles. The tornado, on the other hand, starts
in temperate zones over land, seldom has a width of more than
2 miles and travels much faster than a hurricane. Cyclone is
"a type of atmospheric disturbance characterized by masses of
air rapidly circulating clockwise in the southern and counter
clockwise in the northern hemisphere, about a low-pressure
center, usually accompanied by stormy, often destructive,
weather." (American Heritage Dictionary)

A hurricane is a "tropical cyclone formed over the North
Atlantic, E. North Pacific, and West South Pacific oceans in
which the winds attain speeds greater than 75 miles per hour.
A tropical cyclone passes through two stages, tropical
depression and tropical storm, before reaching hurricane
force. An average of 3.5 tropical storms per year become
hurricanes; one to three of these approach the U.S. coast.
Hurricanes usually develop between July and October. A
hurricane is nearly circular in shape, and its winds cover an
area about 500 miles in diameter. As a result of the
extremely low central air pressure (around 28.35 in /72 cm of
mercury), air spirals inward toward the hurricane's eye, an
almost calm area about 20 miles in diameter. Hurricanes,
which may last from 1 to 30 days, usually move westward in
their early stages and then curve northward toward the pole.
Deriving their energy from warm tropical ocean water,
hurricanes weaken after prolonged contact with colder
northern ocean waters, becoming extratropical cyclones; they
decay rapidly after moving over land areas. The high winds,
coastal flooding, and torrential rains associated with a hur-
ricane may cause enormous damage. Tropical cyclones that
form over the E. North Pacific Ocean and its seas are called
typhoons; those over the Indian Ocean and its seas, are called

Tornadoes, are dark, funnel-shaped clouds containing
violently rotating air that develops below a heavy cumulo-
nimbus** cloud mass and extends toward the earth. The
diameter of a tornado varies from a few feet to a mile; the
rotating winds reach velocities of 200 to 300 miles per hour,
and the updraft at the center may reach 200 miles per hour.
In comparison with a cyclone, a tornado covers a much smaller
area but is much more violent and destructive. The atmos-
pheric conditions required for the formation of a tornado
include great thermal instability, high humidity, and the
convergence of warm, moist air at low levels with cooler,
drier air above. Tornadoes occurring over water are called
"waterspouts." (C.C. Encyclopedia)

** ("KEUM-you-low-NIM-bus"; an extremely dense, vertically
developed cumulus cloud with a relatively hazy outline and a
glaciated top, usually producing heavy rain, thunderstorm, or
hailstorm. American Heritage Dictionary.)

Cyclone is often called a "low," of low central atmospheric
pressure relative to the surrounding pressure. The resulting
pressure gradient, combined with the coriolis effect, causes
air to circulate about the center, or core...The frictional
drag on near-surface air moving over land or water causes it
to spiral inward toward lower pressures; this movement is
compensated for near the center by rising currents, which are
cooled by expansion when they reach the lower pressures of
higher altitudes. The cooling, in turn, characteristically
increases the relative humidity greatly and produces
cloudiness. An anticyclone has the opposite characteristics:
a "high," or region of high central pressure relative to the
surrounding pressure; descending and diverging air that is
warmed by compression as it encounters higher pressure at
lower altitudes; and characteristic low humidity and little
cloudiness. Both cyclones and anticyclones move across the
land at speeds of 500 to 1,000 miles per day. The term
cyclone is also used for a tropical storm of the Indian Ocean
and a tornado." (C.C. Encyclopedia)

Monsoon is a "wind that changes direction with the seasons.
Monsoons are the result of differing air pressures caused by
the varied heating and cooling rates of continental land
masses and oceans. Winter monsoons associated with India and
Southeast Asia are generally dry; summer monsoons in those
regions are extremely wet." (C.C. Encyclopedia) In India,
the monsoon is called "a season of winds." Some areas of
India receive 38 feet of rain per year during the summer

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