Forces of Nature
Focus: Tornadoes
Go to the following website: http://www.nationalgeographic.com/forcesofnature/
Read through the sections in order and answer the following questions.
1. What is a Tornado?

A tornado is a ___________________________________ of air that extends from a
thunderstorm to the ground.

________________-size hail might fall. A ______________ suddenly appears, descending
from a cloud.

The
funnel
hits
the
ground
and
roars
forward
with
a
sound
like
that
of
a
________________________________ approaching. The tornado tears up everything in its
path.

Every U.S. state has experienced twisters, but ___________________ holds the record: an
annual average of ____________.
2. What Causes Tornadoes?

The most violent tornadoes come from ____________________, large ________________
that have winds already in _________________. About one in a thousand storms becomes a
supercell, and one in five or six supercells spawns off a tornado.

Where do most tornadoes in the United States occur?
______________________________________________________________________.

Why do most tornadoes form in the late afternoon?
___________________________________________________________________________
___________________________________________________________________________.

Tornadoes
form
when
_______________,
________________, _________________ air.
causing an updraft.
_______________.
______________
air
collides
with
The warm air rises through the colder air,
This will begin to rotate winds very sharply in _______________ or

Water
droplets
from
the
mesocyclone’s
(rotating
updraft)
moist
air
form
a
___________________________. This continues to grow and eventually it descends from the
cloud. When it touches the ground, it becomes a ________________________.
3. Characteristics of Tornadoes

Once a tornado hits the ground, it may live for as little as a ____________________ or as long
as _____________________. Most don’t travel more than _________________ kilometers
before dying out.

Why are the measurements of tornadoes just scientists’ best estimations?
___________________________________________________________________________
___________________________________________________________________________.
Click the button to See Tornado Damage.
List one piece of information for each tornado strength as measured by the Fujita Scale.
F0
F1
F2
F3
F4
F5
4. What Damage Do Tornadoes Do?

Every year in the United States, tornadoes do about _______________________ dollars in
damages and kill about ___________people, on average.

Winds can also destroy _______________, flip ________________, send ______________
and
________________
flying,
tear
______________________from a riverbed.
the
bark
off
trees,
and
suck
all
the

High winds sometimes kill or injure people by _______________________________________
or _____________________________________________. But most tornado victims are
struck by flying debris – ____________________________, _________________________,
_______________________, and ________________________________.
5. How Are Tornadoes Forecasted?

Meteorologists at the U.S. National Weather Service use _____________________________,
______________________,
__________________________,
and
_____________________________ to watch the skies for severe storms and tornadic activity.

Doppler
radars
record
________________________
and
identify
______________________________ within thunderstorms. Since Doppler radar has been in
use, the warning time for tornadoes has grown from fewer than ___________minutes in the
1980s to an average of ____________ minutes today.

When
weather
conditions
are
conducive
for
tornado
formation,
the
____________________________________ issues a tornado watch. When a tornado has
been sighted or indicated on radar, a ______________________________ is issued.
6. Create a Tornado!
Test out the different options to create a powerful tornado!