Name ______________________________________________________________________ Date _________
1
Tornados are windstorms. At
the center of the storm, the winds
spin around. The winds are really
fast. Some winds have been stronger than 300 miles an hour! Some
people call them twisters. They are the most violent storms on earth.
Tornadoes, Nature's Twisters
By Cindy Grigg
2
Tornados make a funnel cloud. It looks a little like an elephant's trunk
hanging down from a cloud. A tornado funnel may look white or clear.
Some seem to shimmer in the light. After they touch the ground, the winds suck up dirt and debris. Then the
funnel may look dark gray or black.
3
Some of the funnels don't touch earth. Those cause little, if any, damage. Some touch down. They race
across land. They tear up everything in their paths. Some touch down, cause some damage, and then rise up into
the air. They may do this several times. Tornados like this cause damage in spots along the line they travel.
4
Usually there is a thunderstorm in the area first. Sometimes a thunderstorm will cause groups of tornados to
form. These tornados strike one after the other. They may last for several hours.
5
A tornado may be a mile wide. It may travel along a path fifteen or more miles long. Some tornadoes die
out in just a few minutes. Some last an hour or more. The United States has more tornados than any other
country. There are usually about 800 tornadoes a year in the U.S.
6
Every state in the U.S. has had at least one tornado. Most tornadoes strike the middle section of the country,
though. This area has been called "Tornado Alley." It reaches from the states of Nebraska and Iowa south and
east into Alabama and Florida. The deadliest tornado in recent years was in 1989 in the country of Bangladesh.
More than 1,300 people died.
7
You may hear on TV or radio that there is a tornado "watch" or tornado "warning." If a watch has been
issued, it means that a tornado may occur. Weather watchers have seen that the conditions exist for a tornado to
form. If a warning has been issued, it means that a tornado has been seen -by a person or on radar. The warning
will tell you the path the tornado may take. If you are near that path, you should seek shelter.
8
Go to an underground shelter if possible. A basement or cellar is a good place. If you don't have one, go to
an inside closet, bathroom, or hallway that is downstairs. If you're in a mobile home, leave. Take shelter in
another building or a ditch. If you are outside, lie flat in a ditch or the lowest part of the ground. If you are
inside a car, leave it. Lie flat on the lowest part of the ground.
9
Remember that tornadoes are the hardest blowing winds on earth. They are the most violent of storms. Pay
attention when you hear that a tornado watch or warning has been issued. Knowing the expected path of the
storm and knowing what to do can save your life.
1. What does a tornado funnel look like?
2. Which country has more tornadoes than any other?
Australia
Bangladesh
Canada
The United States
3. About how many tornadoes happen in an average
year in the U.S.?
700
500
200
800
4. Alaska and Hawaii have never had a tornado.
False
True
5. Where is "Tornado Alley"?
6. What does it mean when a tornado watch is
issued?
7. What does it mean when a tornado warning is
issued?
8. If you are in a car, you will be safe from a tornado.
False
True
9. If you can, you should seek shelter in a basement
or cellar.
False
True
10. Which country had the deadliest tornado?
Bangladesh
The United States
Canada
Australia
Storm Chasers By Cindy Grigg
1
Have you seen the movie Twister? That movie is about some people who
chase tornadoes. Would you like to be a storm chaser?
2
Storm chasers are people who follow tornadoes to study them. They want to
learn more about where tornadoes are likely to form. They want to increase
warning time for people who are in the path of a tornado. This will help save lives.
But getting information about tornadoes isn't easy. It is hard to predict when they
will form. It's hard to predict where they will go. Once they do form, they don't
last very long.
3
Meteorologists who are storm chasers try to drop weather instruments into the paths of tornadoes. With
these instruments, scientists could collect data about the air temperature and pressure inside the tornado. They
could also measure wind speed and direction. But the paths of tornadoes are erratic. Often the storm misses the
instruments completely.
4
At the National Severe Storms Laboratory (NSSL) in Norman, Oklahoma, meteorologists watch for a
severe thunderstorm to develop. Oklahoma is in "Tornado Alley," an area in the middle of the United States
where tornadoes happen most often. When a severe thunderstorm does develop, computers are used to predict
where tornadoes are most likely to form. Then the storm chasers drive to the storms that are most likely to
spawn a tornado. Storm chasers stay in radio contact with a meteorologist who guides them to the storm system
where a tornado is most likely to form.
5
Storm chasers usually have a degree in meteorology, the study of weather. Some have degrees in physics or
engineering. Some storm chasers are just trying to get it all on film. Some people chase storms as a hobby. They
are thrilled by the power of nature. For all storm chasers, they must be aware of the dangers. Driving in severe
weather is one of the biggest dangers. Then the storms themselves are dangerous, with lightning, high winds,
heavy rain, and hail. That's not even counting the tornadoes! Have you got what it takes to be a storm chaser?
1. Storm chasers follow ______.
Hurricanes
Tornadoes
Snow storms
Hail storms
2. What do storm chasers try to place in the path of a
tornado?
3. Why is it hard for storm chasers to drop their
instruments where tornadoes will pick them up?
4. What type of weather creates tornadoes?
Hot summer nights
Blizzards
Severe thunderstorms
Mild rainstorms
5. Why do storm chasers keep radio contact with a
6. What does "erratic" mean in paragraph 3?
meteorologist?
Not predictable
To tell the meteorologist what to do back at
Variable
the station
Often changing direction
So the meteorologist will know if they were
All of the above
successful
To get directions to the storm system most
likely to create a tornado
To get medical help if they need it
1974 Tornado Outbreak by Cindy Grigg
1
The largest tornado outbreak on record for a single twenty-four hour period happened on April 3, 1974. One
hundred and forty-eight tornadoes were confirmed in thirteen U.S. states. It was called the Super Tornado
Outbreak.
2
A tornado is a violently rotating column of air coming down from a thunderstorm to the ground. Tornados
can last from several seconds to an hour. Most last less than ten minutes. The United States experiences more
tornadoes than any other country. It is considered normal for the U.S. to experience up to a thousand tornadoes
in a year's time.
3
On April 1, 1974, a low-pressure system developed across the Interior Plains. Moist air was added to this,
which created a storm system. The weather forecasters were expecting some severe weather to begin around
April 3, but not to the extent that occurred.
4
Tornadoes today are rated on a system called the Fujita Scale. The scale rates tornadoes based on the
damage they inflict on structures and vegetation. The range is from F0 for light damage such as a few trees
toppling and roof damage, to an F5 in which incredible damage occurs. Winds reach over 300-mph in an F5.
Strong frame houses are lifted off foundations and carried considerable distances. Automobile sized missiles fly
through the air in excess of 100 yards. During the Super Tornado Outbreak there were six tornadoes that
reached the F5 rating. Another eighty-eight reached the F2 rating.
5
On April 3, severe weather watches were in place. Snow was reported in the Upper Midwest that morning.
By afternoon, several more thunderstorm outbreaks were reported from the Great Lakes to the Gulf States. The
worst of them hit the Ohio Valley between 4:30 and 6:30 P.M. Four of them were rated F5 tornadoes.
6
The deadliest of the outbreaks hit Xenia, Ohio at 4:30 P.M. This tornado had a wind speed of 318 mph. One
Xenia resident who was five years old at the time, described his ordeal:
7
"Mom and Dad covered me, shielding my body from flying bricks and shattered glass. The deafening wind
sounded like a team of fighter jets. I saw bedroom doors slamming against the wall before flying off their
hinges. The roof ripped off, and the walls around us crumbled. Between my sobs, I could hear Dad praying for
our protection."
8
Train cars went flying. A semi-truck was picked up and dropped on the bowling alley. School buses were
dropped atop the school. The tornado lasted only nine minutes. There were thirty-two fatalities. Over a thousand
people were injured in Xenia alone. About half the town was destroyed in those nine minutes. Damage to Xenia
was estimated to be $400 million in 1974 dollars.
9
The storm activity in other areas increased that evening. Several violent tornadoes crossed the northern half
of Alabama. Activity was reported once again in Kentucky and Tennessee. Several more killer tornadoes were
reported in the area around southern Michigan between 6 and 10 P.M. The final tornadoes hit the southeast
during the morning of April 4. All told, the United States had experienced a total of 148 tornadoes within this
twenty-four hour time period.
10
Six of these were F5 tornadoes. Twenty-four of them were categorized as F4. Another eighty-eight reached
the 113-to 157-mph wind speeds of an F2. During the outbreak, there were a total of fifteen tornadoes on the
ground at the same time. The entire state of Indiana was put under a blanket tornado warning. This was the first
and only time an entire state had been placed under a tornado warning. The outbreak finally ended in North
Carolina at about 7 P.M. on April 4. A total of 315 to 330 people were killed from the wrath of these tornadoes.
Over five thousand people were injured.
11
One very important event came out of the outbreak: the wide use of the Fujita Scale. The Fujita Scale was
actually developed in 1971 by Ted Fujita but it really took hold after this tornado outbreak. His scale was able
to categorize each of the tornadoes that took place in 1974. This scale unified the language for the study of
tornadoes.
12
The National Weather Service has also gone from fifty-two weather stations to more than 120. The biggest
single advance was vastly improved radar to track the development of these storm systems. These advances
have greatly improved the warning system for our citizens.
1. What is the Fujita Scale?
A scale that measures the size of fruit
A scale that measures the weight of a fajita
A scale that measures the strength of a
tornado
A scale that measures Mexican food
2. In an F5 tornado, how strong are the winds?
Under 200-mph
Over 300-mph
Under 70-mph
Under 100-mph
3. How many states were hit by the Super Tornado
Outbreak?
4. What city received the worst tornado damage from
this outbreak?
5. How many tornadoes had touched down in this 24- 6. What important weather tool was widely used after
hour period?
the Super Tornado Outbreak?
The naming of tornadoes
The Fujita Scale
Sonar
Radar
Directions: Read the following stories that describe several actual tornadoes. Classify each tornado from EF0 to
EF5, using The Enhanced Fujita Scale of Tornado Intensity, and state your reasons.
1. On March 18, 1925, at 3:35 p.m., Howard Rawlinson was in his classroom on the third floor of the
Crossville, Illinois, Community High School, when the school janitor burst in and told Howard’s class that if
they had never seen a tornado, they were going to see one now. Howard watched as one of the dark clouds put
two fingers down to earth. The tornado then came to a barn and the two funnels merged and ripped the roof and
some of the walls right up into the air. Some pieces of the barn fell to the ground, and the others started swirling
around the outside the tornado. The tornado was ripping the trees right out of the ground. After the tornado had
left, damage was assessed. Most of the homes had some walls and roofs torn off. There was also the usual
interesting stuff such as straws driven into trees.
Category: ________________________
Reason 1: ______________________________________________________________________________
Reason 2: ______________________________________________________________________________
2. A swarm of huge tornadoes ripped through Oklahoma and Kansas on May 3 and 4, 1999, killing 48 and
destroying thousands of homes. As the search went on in dozens of dazed communities, Oklahoma Governor
Frank Keating told CNN, “I’ve never heard of anything like this... The extent of devastation is unprecedented.”
The governor called out the National Guard. The National Weather Service said that 45 twisters had hit
Oklahoma and 14 had hit Kansas. At least one twister was a mile wide at times. Some of the worst damage
occurred in Oklahoma City, where whole residential neighborhoods were lifted off their foundations and were
wiped out. In Moore, a suburb of Oklahoma City, John Ireland told CNN, “It looks like a bomb hit here. Houses
are just leveled. It looks like a battlefield.”
Category: ________________________
Reason 1: ______________________________________________________________________________
Reason 2: ______________________________________________________________________________
3. The tornado had touched down for about 10 minutes in Nebraska on June 10. The Warrens had noticed the
tornado coming and headed for shelter in their basement. The winds were very strong. After the tornado had
passed, they came up from their basement to assess the damage. Only minimal damage was done to their home.
Some of the shingles were ripped off their roof. Their neighbor was not so lucky. His mobile home had been
pushed over. Luckily, he was out of town. Later that day, the news reported wind speeds of 86 mph (138 kph).
In the city, cars had been moved by the tremendous winds. The windows in office buildings had been broken by
flying debris.
Category: ________________________
Reason 1: ______________________________________________________________________________
Reason 2: ______________________________________________________________________________
Directions: The list below shows, by state, the average number of tornadoes from 1950 to 2005. Use this data, the
completed Map of the United States and information about the meteorology of tornado formation to answer the questions
on the Tornado Worksheet.
Alabama 27
Alaska < 1
Arizona 4
Arkansas 25
California 5
Colorado 22
Connecticut 1
Delaware 1
Florida 55
Georgia 22
Hawaii 1
Idaho 3
Illinois 35
Indiana 22
Iowa 37
Kansas 55
Kentucky 12
Louisiana 27
Maine 2
Maryland 6
Massachusetts 3
Michigan 17
Minnesota 25
Mississippi 27
Missouri 30
Montana 7
Nebraska 45
Nevada 1
New Hampshire 2
New Jersey 3
New Mexico 9
New York 7
North Carolina 19
North Dakota 22
Ohio 15
Oklahoma 57
Oregon 2
Pennsylvania 12
Rhode Island 1
South Carolina 14
South Dakota 29
Tennessee 15
1. Color the areas green that have an average of 0–10 tornadoes per year.
2. Color the areas blue that have an average of 11–20 tornadoes per year.
3. Color the areas yellow that have an average of 21–37 tornadoes per year.
4. Color the areas red that have an average of 38–125 tornadoes per year.
Texas 139
Utah 2
Vermont 1
Virginia 10
Washington 2
West Virginia 2
Wyoming 11
American Samoa 0
Dist. of Columbia < 1
Guam 0
Puerto Rico < 1
Virgin Islands 0
Directions: Use Map of the United States and Tornado Strikes to answer the following questions.
1. How many states and U.S. territories have an average of 0–10 tornadoes per year? ____________________
2. How many states and U.S. territories have an average of 11–20 tornadoes per year?___________________
3. How many states and U.S. territories have an average of 21–37 tornadoes per year?___________________
4. How many states and U.S. territories have an average of 38–125 tornadoes per year?___________________
5. The area of the United States that seems to be most prone to tornadoes is called Tornado Alley. Most
tornadoes, especially severe tornadoes, have struck here. Use the data you have compiled to name the states that
are included in Tornado Alley.
__________________________________________________________________________________________
Twister the movie vs. Real life:
You must answer 15 of the questions for full credit. Extra questions = extra credit
1. In 1969, where did the family receive a tornado warning?
2. Where did the family go for safety during the storm?
3. What is the name of a satellite used for present day weather observations?
4. The NSSL is the National _______________ Storm Laboratory.
5. What is Dorothy?
6. How many minutes is the current advance warning for a tornado?
7. DOT 3 has hundreds of sensors to transmit wind _________________, ______________, and dewpoint
temperature.
8. Outside the coffee shop, what color is the sky turning?
9. Where do Jo and Bill hide to avoid the tornado?
10. Near the next tornado, what is moving horizontally?
11. What is the color difference of the tornado over the water compared to the tornadoes over the land?
12. What property of a tornado is measured by the Fujita scale?
13. What is the ground speed of the tornado being chased?
14. How wide is the tornado?
15. What form of precipitation do Jo and Bill encounter as they approach the tornado hidden behind the hill?
16. What is happens to the television reception of the TVs near the drive-in?
17. What are the storm chasers trying to do as they hide in the garage from the tornado? (where are they trying
to be?)
18. After Aunt Meg is rescued, what is the Fujita intensity of the tornado identified by the NSSL?
19. What is added to Dorothy's sensors to make them fly better?
20. What do you think caused the numerous small dents in the pickup truck?
21. What do Jo and Bill use to weigh down the sensor pack so it can enter the tornado?
22. When Jo and Bill are inside the tornado, what do they see above the tornado?
23. What must be done to the data collected from the tornado?
24. Looking carefully at the end of the film, how can you tell where a tornado has been?
******************************************************************************************
For extra help with the questions below, listen and watch the footage from National Geographic:
http://www.nationalgeographic.com/outthere/profile_storms.html
Choose two (2) questions below and write a well-developed paragraph (on loose leaf) for each using
information gained from the reading comprehension worksheets and videos.

Choose one scene from the movie, Twister, which seems too good to be true. Describe the scene and
explain why you think the scene would never happen in real life. Give at least two (2) reasons.

Why is it so important to be able to accurately predict tornadoes?

What are some of the problems researchers face when trying to predict tornadoes? Why is it so difficult?

What are some of the technologies that have been used to track storms and predict tornadoes? Which
ones were unsuccessful, and why? Which technologies do scientists think are going to prove most useful
in the future?

What have researchers learned about tornadoes so far, and what do they hope to learn in the future? How
will technology help?

Would you like to be storm chaser? What do you think a day in the life of a storm chaser would be
like? What would be the best parts about it? What would be the worst?