is a tornado?
The technical definition of a tornado is a violently rotating column in
contact with the ground that is usually pendant from a parent cumulonimbus
cloud. The vortex is usually, but not always, made visibly by a condensation
funnel cloud and/or a drbris cloud. On a local scale it is the most destructive
of all meteorological phenomena. Many tornadoes only last for a few minutes
and are on the ground for a few miles. But others can persist for hours,
travel more than a hundred miles, and have paths a mile wide. The word
tornado may have originated with a merging of the Latin tornare,
which means to turn, and the Spanish tronada (thunderstorm).
is the difference between a funnel and a tornado?
Both are violently whirling columns of air spawned by thunderstorms, but
in most usages of the word, the funnel refers to a vortex which is still
aloft whereas a tornado has descended to the surface. If the condensation
funnel has dropped more than half way from the cloud base to the surface,
a funnel is generally called a tornado because by this time damaging winds
are likely to be occurring on the ground. Sometimes the term funnel refers
to the visible portion of the vortex whether the or not the circulation
has reached the surface. The funnel can be made visible by either condensation
(the funnel cloud) or debris or both. GO
What causes tornadoes?
Conservation of angular momentum. Everyone has seen ice skaters who are
spinning while extending their arms and as soon as they tuck their arms
in close to the body, the rate of spin increases dramatically. Somewhat
the same thing happens in the atmosphere. An air mass always has a certain
amount of spin (technically called vorticity). As that air
is converged into the strong updraft of an intense thunderstorm, the rate
of spin increases, much like that of the skater. But while the basic principle
is recognized, the meteorological mechanisms are still poorly understood.
Do tornadoes form deep within the cloud and extend downward? Or does the
intense rotation form beneath the cloud and extend upwards. Or both? A
major research program was held during 1995 called VORTEX (verifying the
origins of rotation in tornadoes experiment) in which hundreds of meteorologists
drove around, flew near, electronically probed and photographed tornadic
thunderstorms from every conceivable angle. But unlike the movie Twister
where the answer was immediately obvious, it will
take years of data analysis to fully understand just what puts the twist
in the twister.
is Tornado Alley?
A broad belt of the interior U.S. which extends from Texas northwards,
has more tornadoes than any place in the world. This is often called tornado
alley, although its exact geographic boundaries are ill-defined. Tornadoes
are not confined to this region, however. Tornadoes have been observed
in every state.
GO TO TOP
is the Fujita Scale?
Just as there is a "Richter Scale to gauge earthquake intensities,
the "Fujita Tornado Scale," based upon damage, classifies twisters
into six categories of wind speed (FO through F5), ranging from 40 to
300+ mph estimated wind speed. Placing sensors inside an F5 tornado became
the quest of the meteorologists in the movie Twister. The
Fujita scale was devised by Prof. T. Theodore Fujita (everyone calls him
Ted) of the University of Chicago. He is also called Mr. Tornado
because he conducted much of the pioneering work on tornadoes which serves
as the basis of todays rapidly improving understanding of severe
storms. Since no one has ever been able to obtain wind measurements inside
a tornado (except for some recent Doppler radar studies), Prof. Fujita,
along with Allen Pearson, then the Director of the National Severe Storm
Forecasting Center, devised a way to convert the degree and type of damage
caused by a tornado into an estimate of the wind speeds inside the funnel.
Correctly using the F scale requires a lot of skill, but it
is still the best tool available today. Almost all tornadoes for the last
several decades have been classified according to the F rating.
The Fujita tornado
intensity scale in terms of the peak wind speeds within the funnel:
F0 (light damage):
F1 (moderate damage): 73-112 mph
F2 (considerable damage): 113-157 mph
F3 (severe damage): 158-206 mph
F4 (devastating damage): 207-260 mph
F5 (incredible damage): 261-318 mph
No tornado is believed
to have exceeded F5, which itself is reached only a few times per year
in the 700-800 annual US tornadoes. The 3 May 1999 tornado in the Oklahoma
City area was observed by a portable Doppler which indicated winds at
the very end of the F5 scale, the strongest yet measured.
Note: In 2007, an enhanced Fujita (EF) Scale was introduced. Details can be found on the web site of NOAA's Storm Prediction Center:
many tornadoes reach violent status?
Tornadoes of F4 or F5 on the Fujita scale are classified as violent tornadoes.
Only 2% of U.S. tornadoes reach violent intensity, yet those
few result in 70% of all tornado deaths. Their winds exceed 200 mph and
they can stay on the ground for an hour or more.The strongest tornado
wind speeds are estimated to be in the 260-318 mph class. This corresponds
to a ranking of F5, the highest on the Fujita tornado scale. During the
last decade, less than a dozen twisters were estimated to reach this kinetic
milestone. GO TO TOP
When do tornadoes occur?
Whenever they want to. There is no real tornado season since they occur
in the U.S. during any month of the year, though the winter months see
them retreat to the far south and southwestern part of the country. April
is sometimes called the "cruelest month". And it is. As far
as U.S. tornado deaths are concerned, it has the highest toll. But numerically
the most tornadoes occur in May, although they tend to be somewhat less
violent and therefore less deadly. While the tornado season
is generally considered to be March through August, twisters can occur
whenever atmospheric conditions are right.
The tornado season
never really ends, it just slows down, and occasionally springs back to
life during what should be winter. On December 9, 1991, a tornado smashed
through McLean County, IL. About 20 empty railroad cars were blown off
the tracks near Bloomington. A camper was picked up, tossed 100 feet and
hurled into a tree. Fortunately the camping season had ended.
In the U.S., April
has the most tornado fatalities. May has the most tornado touch downs.
July has the most lightning strikes. And September the most hurricanes.
So, that leaves June and August for vacations?
is the peak time of day for tornadoes?
Tornadoes are creatures of the late afternoon, when most thunderstorms
are in progress. Over 40% of U.S. twisters are reported between 2 and
6 PM. But they can and do strike at any hour if conditions are right.
Nighttime tornadoes tend to be rather common along the U.S. Gulf Coast,
the hour of the day making them even more deadly because they are obviously
harder to see, and most people are sleeping and unaware of warnings (unless
they have a NOAA Weather Radio with Tone Alert). Early morning tornadoes
are unusual by not impossible. The only tornado directly witnessed by
the author whizzed past his front door at 8:15 on a Saturday morning while
he was out picking up the newspaper. GO
shapes can tornadoes take?
Most people have a mental image of a tornado...rather like an elephant's
trunk ...yet twisters come in a variety of shapes and sizes. Sometimes
they appear as roiling billows of smoke, other times a twisting rope,
or a barely visible swirl of dust. Some extremely violent ones appear
as several "snake like" vortices whirling around a common center.
Some especially large funnels, which can be a mile wide, are sometimes
called wedges. A tornado often goes through a life cycle starting as a
classic funnel shape, then broadening and widening in its mature stage,
sometimes almost looking like billows of smoke on the ground. Then it
enters the dissipating stage where it becomes thinner, long and often
very distorted. This is called the rope stage. But even when a tornado
is roping out it can still pack a pretty good wallop at the
are the strongest winds in a tornado?
How high are the strongest winds in a tornado? Once they were thought
to be over 500 mph, perhaps even supersonic. But research on damage patterns,
as well as recent measurements made by portable Doppler radars suggest
the highest winds are in the 280-320 mph range. Still a pretty fair breeze.
The strongest wind speeds in a tornado vortex are thought to occur about
300 feet above the ground. It is estimated that fully 90% of all tornadoes
fail to register winds above 113 mph. GO
are suction vortices?
The ability of a passing tornado to destroy a building yet leave something
only a few feet away totally unscathed has long been a puzzle. Detailed
studies by Prof. T.T. Fujita of tornado films and videos as well as airborne
surveys of tornado damage demonstrated that many funnels break down into
smaller vortices rotating about a common center and moving along with
the mean speed of a tornado. These features, only tens of feet across,
cause much of the major damage and "freakish" destruction. These
suction vortices, as they are called, have dramatically higher wind speeds
than their parent funnel cloud. Thus when the main funnel passes over,
whether a house is severely damaged or not may depend on whether it gets
nailed by one of these smaller whirls. Some multi-vortex funnels do not
look like the commonly held image of a tornado, but can sometimes appear
to be swirls of smoke and multiple snake-like columns whirling about a
there other tornado-like vortices in the atmosphere?
Aside from dust devils and steam devils, intense atmospheric whirls can
be found when there are unusually strong heat sources. Forest fires can
induce intense fire whirls that can exceed 100 mph and extend for more
than a mile in height. Similar vortices have been seen spring away from
volcanic eruption clouds, the Kuwaiti oil fires during the 1991 Gulf War,
and sometimes even in the exhuast plumes of large power plants. GO
rivers protect you from tornadoes?
No way. There are numerous reports of twisters crossing major rivers such
as the Mississippi and Missouri, damaging towns on both sides. And at
least 30 significant tornadoes have crossed the Mississippi River. More
than one river boat has been struck and sunk by twisters.
do tornadoes form with respect to the parent storm cell?
Tornadoes have a strong tendency to form near the right rear portion of
a thunderstorm cell, particularly if it is an isolated storm called a
supercell. The apparent mesocyclone, out of which many tornadoes form,
is often centered in this updraft region of the storm. To the north and
east are falling the heavy rain and hail. But the mesocyclone, which often
appears as a hook-shaped echo on radar, tends to feature largely powerful
updrafts, and therefore the region is characterized by a rain free base.
Thus many tornadoes occur in areas with little rainfall (though sometimes
large hailstone may be falling). This explains why many tornado pictures
show clear skies in the background. GO
is a wall cloud?
A wall cloud is a feature that accompanies and processes many tornadoes.
Its appearance is noted by severe storm spotters with concern and is a
visible manifestation of the tornado mesocyclone. It is an often abrupt
lowering of the rain-free base of the cumulonimbus cloud into a roughly
circular, low hanging cloud, one to four miles in diameter. The wall clouds
often have rapidly rising elements and are often rotating in the same
direction as the tornado, but at a much slower speed. The collar cloud
is a ring of cloud that sometimes surround the upper portion of the wall
cloud. The rotating wall cloud has been known to to appear as much as
an hour before touchdown.
are tornado chasers?
Crazy. Or least some of the amateurs who dont really understand
what they are getting into could be described this way. Tornado researchers
have been chasing storms (ideally driving to areas where they believe
storms will form and then setting up for observations) for over two decades.
The early chasers were associated with the National Severe Storms Laboratory
and understood the behavior of severe thunderstorms and tornadoes. The
chasers goal is to get close enough to get good data (whether video,
radar or other measurements) but to stay far enough away in order not
to get hurt or killed. There are also other hazards including giant hail,
lightning, downburst winds and rain slick roads. The movie Twister
glamorized storm chasing, but was highly unrealistic. No serious meteorologist
in their right mind would attempt getting as close to the funnels as portrayed
in the movie. Anyone inspired by the film to try a little chasing had
first better read up on what its like out there - that first grapefruit
size hailstone smashing through your windshield while you are driving
75 mph down an Interstate can ruin your day - and life! GO
hurricanes spawn tornadoes?
Yes, and quite frequently. During hurricanes, tornadoes are a hazard.
Some land falling tropical storms have spawned dozens of small twisters.
They frequently occur on the outer fringes of the advancing storm. It
is by no means unusual to be under both a tornado and hurricane watch
or warning at the same time. Hurricane Beulah (1967) generated as many
as 115 tornadoes upon making landfall in the U.S.
are the tornado death tolls for the United States?
Over 10,000 Americans have been killed by tornadoes in this century. There
have been, since 1880, at least 31 tornado outbreaks taking more than
100 lives. Between 1961 and 1990, the state with the highest annual average
tornado fatality rate has been Mississippi (10 per year) followed by Texas
(8), Indiana (7), Alabama (6), and Illinois, Ohio and Arkansas tied at
5 per year. The tornado death toll has been steadily decreasing, due in
large part to improved warnings, communications, emergency preparedness
and perhaps partially of the shift of population into urban areas.
was the single deadliest U.S. tornado outbreak?
The worst single tornado tragedy in the United States was the Tri-State
tornado outbreak (Missouri, Illinois and Indiana) of 18 March 1925. Several
tornadoes claimed a total of 747 lives with an additional 2027 persons
being injured. The largest of these twisters killed 695 persons, the worst
single tornado casualty toll ever. GO
were the deadliest years for tornadoes in the U.S.?
The deadliest year for tornado deaths in the U.S. was 1925, when 794 died,
many in the infamous Tri-State tornado in Missouri, Illinois and Indiana.
In more recent years, 1953 was grim, with 519 fatalities. Tornadoes in
May and June, 1953 were especially deadly. On 11 May, 114 died in Waco,
TX. On June 8, 116 perished in Flint, MI. The next day the weather system
spawned a tornado in Worcester, MA, resulting in the loss of 90 more lives.
The year with the fewest reported U.S. tornado deaths is 1986, when only
16 citizens perished.
are the longest and shortest tornado paths on record?
A tornado on 18 March 1925 was believed to have stayed continuously on
the ground for 215 miles. The Great Tri-State tornado swept across portions
of Missouri, Illinois and Indiana. In 1917 a tornado was reported to have
traveled from Missouri to Indiana - a distance of 293 miles - while staying
on the ground for seven hours and 20 minutes. But without a detailed damage
survey it is difficult to tell whether the track may not have resulted
from several successive tornado touchdowns. At the other end of the spectrum,
one tornado touchdown was reported to be on the ground for a mere seven
was the biggest recorded tornado outbreak ever?
During the century, the largest single tornado outbreak occurred on 3-4
Over a span of 16 hours some 148 tornadoes slammed into 13 states east
of the Mississippi plus the province of Ontario. Some 315 people were
killed, 5,484 persons were injured and property damage was a half billion
(1973) dollars. The total number of miles of tornado path lengths was
2,598, with a mean path length for each twister of 19 miles. Six of the
148 funnels reached F5 intensity status. Six towns were struck not once,
but twice, in one day. The City of Xenia, OH saw both fortune and misfortune.
While many people were killed and the high school was largely destroyed,
most of the students had departed for the day. A group practicing a play
in the gymnasium saw the funnel approaching and were able to reach a safer
hallway just in time. A school bus was hurled through the roof onto the
stage where they had been practicing. GO
are some other famous tornado outbreaks?
Palm Sunday (11 April) 1965 ranks as perhaps the second greatest outbreak
of U.S. tornadoes. Some 37 tornadoes killed 271 midwesterners. The injury
toll was greater than 5000.
The 3 May 1999 outbreak
in the Oklahoma City area produced over 50 touch downs, many in urban
and suburban areas. Over $1 billion in property losses were tallied, with
around 50 fatalities. One of the twisters were reported to have a peak
wind speed of about 315 mph, as determined by mobile Doppler radar, making
it the strongest wind ever recorded on Earth.
On 21 November 1992,
some 94 twisters blasted 13 states , ranging from Mississippi to Indiana
to Maryland, leaving 26 dead, 641 injured and causing $291 million in
damages. On 28 March 1984, 22 tornadoes killed 57, injured 1,248 and left
behind $200 million in damages in South and North Carolina. Ohio, Pennsylvania
and Ontario were ravaged by 41 tornadoes on 31 May 1985, killing 75 (in
the U.S.) , injuring 1.025 persons and damaging $450 worth of property.
One may note that
these outbreaks did not occur in what is normally thought of as tornado
alley. Large outbreaks can and do occur almost any place east of the Rockies.
But in the alley from Texas to Iowa on 26-27 April 1991, 54 tornadoes
touched down, killing 21, injuring 208 and causing $277 million in damages.
GO TO TOP
are your chances of being struck by a tornado?
Even if you were to camp out permanently in the heart of tornado alley,
statistically speaking you would most likely have to wait 1400 years before
being struck by a twister. Thus the point probability of direct
strike by a tornado is pretty small. But there is an awful lot of tornadoes
and points in the U.S., so during the peak of the season,
at least five a day are touching down somewhere in the U.S. Many tornado
researchers have never seen a tornado. Prof. T. T. Fujita, of the University
of Chicago, called Mr. Tornado by many, had to wait more than
30 years before seeing his first live tornado. His custom license plate
long described his period of frustration, TT 0000.
is a waterspout?
A tornado over water is often called a waterspout. It is generally weaker
than its landlubbing cousins. The area around the Florida Keys is prime
waterspout territory. Peak winds are typically in the 50 to 100 mph range,
enough to flip over the dingy for anyone thinking its cool to sail
into one. Some waterspouts have moved inland causing damage and injuries
so they are not to be taken lightly. Waterspouts generally are not associated
with severe storms, but with average rain showers and weak thunderstorms.
They are sometimes found over the Great Lakes, and even the Great Salt
Lake, during period of intense cold air outbreaks over the warm water.
When a genuine tornado just happens to move offshore, say crossing a lake
or a river, it may be technically called a waterspout, but it doesnt
know that. It is still a tornado - just located over water.
Two men were reported
missing on 18 June 1993 after a waterspout swept through Chicagos
harbor. One man was blown off a pier while the other, a wind surfer, was
nowhere to be found after the vortex passed. GO
is a dust devil?
Dust devils are atmospheric whirlwinds which, while superficially resembling
small tornadoes, form by totally different mechanisms. These swirling
columns, which can rotate either clockwise or counterclockwise, form on
sunny, hot days with relatively light winds, often over plowed fields
or expanses of dirt or pavement. They result from superheated air near
the sun baked ground rising into the cooler air aloft. These whirling
dervishes, unlike the tornado, are not associated with thunderstorms.
In some cases, wind speeds can kick up well over 50 mph. In a few cases,
they have been seem to extend to over 5000 feet above ground.
Most dust devils just
swirl across an open field and kick up a few puffs of dust and a handful
of leaves. Some exceptionally large and long lived dervishes, however,
if traveling over loose soil, can sweep upwards of 50 tons of dust and
are some unusually strong dust devils?
One of the biggest ever formed over the Bonneville Salt Flats in Utah.
It grew to 24500 feet altitude and traveled for over 40 miles. One huge
dust devils was seen swirling away while standing in place for over an
hour in a trucking terminal near Des Moines. A large dust devil in New
Mexico developed at the edge of a railroad embankment and excavated over
a cubic meter of sand per hour for over four hours! It stopped only when
a bulldozer was parked nearby, apparently interrupting the airflow into
the vortex. Some dust devils have been known to overturn trailers and
even down power lines in Arizona.
An unusually powerful
dust devil swept a 300 yard long swath near Minong, WI on 6 May 1995.
It damaged the roof of a house, tore through a snow fence, and caused
a small fire when it downed a power line.
One day in March 1995,
it was a beautiful sunny day in upstate South Carolina, with barely a
cloud in the sky. Suddenly, a covered porch at a rural residence was smashed
to smithereens by a sudden gust of wind with wreckage scattered over several
acres. What happened? The best explanation is that a large dust devil
swirled up from the hot ground. Most dust devils have winds under 50 mph
and rarely cause damage, but as evidenced above, some are larger. GO
state is Number 1 in tornadoes?
We are not sure why a state would want that distinction, except perhaps
to attract the producers of the sequel to Twister to go on
location, but that seemingly simply question has a large variety of answers.
It depends on how you define Numero Uno:
Texas - number of
total tornado deaths (regardless of size)
Oklahoma - number of significant and violent tornadoes per square mile
Florida - number of tornado touchdowns per square mile, of any intensity
Arkansas - highest number of killer tornadoes per square mile
Kansas - highest number of F5 t intensity tornadoes since 1880
Iowa - greatest number of F5 tornadoes per square mile
Tennessee - highest percentage of tornadoes that causes fatalities
Alabama - highest percentage of tornadoes rated as of significant intensity
Kentucky - highest percentage of all tornadoes ranked as violent (F4 or
Indiana - highest rank on scoring system measuring all aspects of tornadoes
Mississippi - highest percentage of population killed by tornadoes
Delaware - highest concentration of tornadoes causing injury
So, who is number
one? Statistics, it has been said, can be used the way a drunk uses a
lamppost, either for enlightenment or support. Or as Mark Twain said,
There are three kinds of lies: lies, damn lies, and statistics.
it possible to survive a tornado?
Yes. In fact the odds are very much in your favor if you follow the basic
safety rules. During the monster outbreak of 3-4 April 1974, over 30,000
people were directly involved inside tornadic vortices. While 315 people
did perish, a full 99% of those directly affected by the tornado outbreak
are most at risk in tornadoes?
Persons in mobile homes and automobiles, and in general the elderly, the
very young and the physically or mentally impaired. Also at risk are those
who have a language barrier to understanding a tornado warning as well
as anyone else who doesnt take precautions when a tornado threatens.
can you do before a tornado to improve your survival odds?
Its too late to buy a smoke detector after the fire starts. And
there are some things you should do before a twister is coming up the
driveway. When a tornado warning has just been issued and/or you see a
twister bearing down on you, you should move to a pre-designated shelter
(basement or interior room). Everyone in the home/school/office should
know in advance where to go. You should consider having drills. Be sure
you know what county you live in, or are visiting (surprisingly many people
dont), since warnings are often issued on a county basis. Have a
NOAA Weather Radio with a warning alarm to automatically receive warnings.
Also monitor commercial radio and television. Have a supply of batteries
for flashlights and the weather radio as well as a first aid kit. GO
should you do if a tornado threatens?
If there is warning, or skies appear threatening, do not panic. But be
prepared to move immediately to a pre-designated shelter, such as a basement.
Remember, at night or during heavy rainstorms waiting before you can see
the funnel before taking action can be a fatal mistake.
If an underground
shelter is not available, move to an interior room or hallway on the lowest
floor and get under a sturdy piece of furniture. Bathrooms, with their
reinforcing plumbing, are often relatively good shelters. The bathtub
itself is a good option. Stay away from windows at all costs - flying
glass is a major hazard. If caught outside, lie flat in a ditch, culvert
or ravine, or any depressed area that may shelter you from flying debris. Do not seek shelter under a bridge or overpass, as the winds can be chanelled though at even greater speeds, carrying deadly misiles. The overall goal is to avoid being struck
by flying debris. Mobile homes, even if tied down, offer little protection
from tornadoes, and should be abandoned. Protect your head from flying
debris. Wearing a football or motorcycle helmet is not a bad idea. The
scene in Twister in which the stars lash themselves to a well pipe when
being engulfed in the F5 funnel made no sense whatsoever. They would have
been blasted by high speed debris and would have looked like beef jerky
by the time the funnel was through with them.
A good source of current tornado safety tips is NOAA's Storm Prediction Center: www.spc.noaa.gov/faq/tornado/#Safety
a train a safe place to be during a tornado?
.The passenger train The Empire Builder had a confrontation
with a large tornado on the tracks near Moorhead, MN on 27 May 1931. The
train lost. Eight coach cars, each weighing more than 80 tons, were derailed.
One shifted more than 80 feet off the tracks. One passenger was killed
are the signs of an imminent tornado?
Even with todays advanced radars and spotter networks, tornadoes
can form suddenly and unexpectedly, without warning. Your own senses then
become your front line of defense. Especially if there have been severe
thunderstorms present in the area, a loud, thunderous roaring noise growing
ever louder should be cause for immediate alarm. Many tornadoes occur
outside the rain area, so dont assume that the lack of rain is a
good omen. In fact tornadoes can even strike when you can see a lot of
blue sky. Large hail is often present in the vicinity of funnels. GO
you open windows or doors during tornado warnings?
NO! This is an old wives tale. Creating an opening for the wind may actually
increase damage and in any case being near a window exposes you to deadly
flying glass. It used to be thought that much of the damage from tornadoes
resulted from unequalized air pressure as the funnel moved over a building.
It is now ascertained that it is primarily the wind effects that cause
most structural damage. Any opening, including a garage door, that allows
for the wind to enter the structure and begin acting on walls
and ceilings increases the chance of damage.
tornadoes unique to the United States?
No, tornadoes occur in many countries around the world, although three
out of four twisters do touch down in the U.S. of A. They tend to occur
at mid-latitudes in regions experiencing strong surface fronts and jet
streams aloft. Tornadoes are rare in the tropics. Australia may be the
closest to the U.S. in term of tornado potential, but the sparse population
makes a climatology difficult. Other countries experiencing a significant
number of twisters include New Zealand, South Africa, Argentina, and in
the northern hemisphere, much of middle Europe from Italy north into England
and Russia. Jolly olde England actually can get some jolly severe weather.
While nowhere near as frequent as in the US, at least 50 tornadoes were
reported in an 82 year period ending in 1949. October is the peak month
for British twisters. Japan, eastern China, northern India, Pakistan and
Bangladesh. Twisters have even spun up over Bermuda and the Fiji Islands
are also at risk.
Though the frequencies
of touchdowns are much less than in the U.S. other countries suffer fatalities
from tornadoes. On 24 June 1904 a killer tornado swept through portions
of Moscow, Russia taking at least 24 lives. On 19 march 1978, a tornado
struck New Delhi, India. Seventeen persons perished and 700 were injured.
In 1995 hundreds were reported killed in a tornado in Pakistan. GO
is the first known movie record of a tornado?
While spectacular tornado shots made with home camcorders are now almost
commonplace on the nightly news, getting such footage in the old
days wasnt so easy. The first known film of an actual tornado
was made in 1933. This is nearly two decades earlier than the 1951 Corn,
OK tornado film once believed to be the earliest. And no, The Wizard
of Oz did not use actual tornado footage. It was a Hollywood special
effect - and a pretty darn good one. Video of an actual tornado taken
several years ago looks spookily similar to the one which whisked Dorothy
off to Oz.
tornado almost changed American pop culture?
A tornado almost changed the course of popular music in the 20th century.
On April 5, 1936, a devastating tornado ravaged Tupelo, Mississippi, killing
over 200 residents. One of those who survived the devastation was an infant
by the name of Elvis Aaron Presley.
anyone even seen the inside of a tornado?
And lived to tell about it......Yes. On 3 May 1943. McKinnet, Texas farmer
Roy Hall survived the day. Not a bad feat since he had found himself trapped
inside a 150 yard wide tornado funnel, and was able to look straight up
into the rapidly whirling vortex for over a thousand feet. It looked rather
like the inside of an elephants trunk. It also had a small mini-tornadoes
spinning of the smooth wall of clouds, and these were illuminated by almost
constant lightning. GO
many tornadoes actually kill people?
Only between 1 and 2% of U.S. tornadoes result in human fatalities. During
1993, there were 1167 confirmed twister touchdowns. Of these only 16 resulted
in deaths. This is a testament to the ongoing improvement in the timeliness
and accuracy of the National Weather Services tornado watches and
warnings. It also suggests that once warned, it is relatively easy to
find a safe haven even if a tornado is bearing down on you.
cows fly in tornadoes?
Yes. As do pigs, horses, and pickup trucks. A large tornado swept through
Eau Claire County, Wisconsin on 27 August 1994. Among the casualties were
200 dairy cows. The storm could be said to have caused udder destruction.
A twister swept through the grazing lands around Ashley, ND on 6 July
1962. And while it failed to strike any building, it did roar though a
herd of cattle, leaving 68 animals dead in its wake.
tornadoes have "eyes?
The eye of a hurricane is the often clear, nearly calm center about which
the violent storm rotates. But does the much smaller tornadic vortex have
a similar "calm" core? Very possibly. Both theoretical and observational
evidence suggests that the inner portion of the tornado funnel may be
largely cloud free and have relatively light winds. GO
cities attract tornadoes?
This is not easily answered. Population density significantly affects
the probability for a tornado being detected and reported. In many rural
areas there is nothing for a tornado to hit, nor anyone there
to see it not be hit. Moreover, in rural areas in the past people have
been less prone to report tornadoes to authorities. Thus the statistics
are biased to more heavily populated areas. Some have even suggested that
tornadoes tend to avoid cities, but there seems to be little evidence
of this. Build it and they will come. Unfortunately this may apply to
cities and tornadoes. Scientists at Texas A&M University find that
urban and suburban counties are more likely than primarily rural counties
to experience tornadoes.
is the largest death toll from a tornado?
If one broadens the definition beyond humans, this case might be a leading
candidate. On 26 April 1994 a tornado swept through a turkey farm in Barron
County, WI. As one might expect, this foul wind flattened the fowl - some
is the record for July tornadoes?
July 1993 set an all-time U.S. tornado record for that month with 234
twisters touching down. A normal July total is 94, but July,
1993 was hardly normal, it being the peak of the Great Floods of 1993
in the Mississippi and Missouri River Valleys.
tornadoes attracted to trailer home parks?
One might think so, given the frequency with which they appear in storm
damage reports. The reasons are twofold. First, there are many more trailer
home parks in the nation than people realize. Second, the construction
of these homes is such that they provide far less resistance to strong
winds than conventional construction. If not properly tied down, they
can begin to fly at wind speeds not much over 70 mph. Trailer
home parks should have storm shelters. Never try to ride out a tornado,
or even a severe thunderstorm in a trailer home. GO
A tornado ripped through
a southeastern Tennessee trailer home park on 26 April 1994. A man was
killed. His daughter and grandson were in a nearby trailer which was also
destroyed, but the daughter landed in a pile of rubble 300 yards away
and the 9-month-old infant was tossed 100 yards. Both were injured but
Why do you think they
call them mobile homes? On August 5, 1992, a South Carolina tornado rolled
a mobile home over THREE TIMES - and its lucky occupant managed to walk
away without serious injury.
you have a tornado when the sun is shining?
Yes. Many tornadoes occur very close to the edge of the violent thunderstorm
cloud that gives them birth. It is entirely possible, especially in the
hour or so just before sunset, that the tornado itself could be in full
sunlight for much of its life cycle.
the number of tornadoes increasing?
No, but the statistics are going up. In the 1950s there were 4,793 tornadoes
reported in the United States. In the 1980s, there were 8194. Climate
change? No. More people now live in or travel through the most tornado
prone parts of the nation. There are now vastly better means of communications
and the reporting of severe weather (if you see a twister, call 911,if
you can do so safely). GO
tornado fatalities increasing?
No, in fact there has been a long term downward trend in tornado deaths
in the U.S., in spite of a steadily increasing population. In 1993, a
then record number of 957 severe thunderstorm and tornado watches were
issued by the National Severe Storms Forecast Center (now named the Storm
Prediction Center). The 1993 death toll from severe thunderstorms and
tornadoes dropped to 33, well below the 30-year average of 82 fatalities.
In the pre-forecast days in the 1930s, tornadoes alone killed almost 200
people each year.
day is least likely to see a tornado in the U.S.?
If recent history is any guide, the 16th of January is a good bet, the
only day of the year in this century (through 1993) on which a tornado
touchdown has not been reported somewhere in the United States. There
is at least one tornado touchdown somewhere in the U.S. on at least half
the days of a typical year. More than ten tornadoes in a single day occur
only 2.4 % of all days, or 9 times per year.
there double jeopardy in tornado strikes?
Since tornadoes are relatively rare, at least in these regions that you
might have to wait centuries for one to strike any given point, you would
figure that once you have been hit by a tornado, it would be clear sailing
from then on out, right? Sure, but there are always exceptions. Statistics
alone can not protect you.
When Your Number Is
Up Department: on 2 December 1982 a Missouri man was injured when his
home was flattened by a tornado. He moved into a trailer home for temporary
shelter - and three weeks later was killed when a second tornado came
Right Place at the
Wrong Time Department: a house in Collinsville, IL was destroyed by a
tornado on 18 May 1883. The rebuilt structure was hit again on 30 March
The possibility of
a building being struck by a tornado is rare, typically less than once
per thousand years. But one church in Guy, Arkansas has been damaged by
twisters three times during the last century.
will have to wait hundreds of years to be struck by a tornado standing
at any one spot in "tornado alley". But on 16 Match 1942, Baldwin,
MI was lashed by a tornado, and before the clean up could even begin,
another twister trotted through town only 25 minutes later.
War is hell but nothing
like Nebraska ... a sentiment that must have been expressed by the Spanish
American War veteran who returned home to Nebraska in 1899, only to have
his house destroyed in a twister. He moved to Omaha, only to have his
house destroyed again in 1913. There is no record of whether he went off
to fight in World War I where it may have seemed safer. GO
do the residents of Codell, Kansas get nervous every May 20th?
May 20th is a day on which the residents of Codell, KS probably watch
the sky with more than the usual interest. In 1916 on that date the area
was swept by a tornado. And again on 20 May 1917. And again on 20 May
1918. Things have been quiet since, but you never know
the southwest corner of the basement the safest?
The southwestern corner of the basement is NOT the safest place to hide
during a tornado - in fact it may be more dangerous than other parts.
Your best chances to avoid injury or worse are to be under a stairwell
or heavy table that can protect you from flying or collapsing debris.
are tornadoes detected?
The new nationwide network of NEXRAD Doppler radars being installed is
designed specifically for tornado warning purposes. While, except under
unusual circumstances, the NEXRAD cannot detect the actual tornadic vortex,
it often can spot the larger scale rotation (the tornado mesocyclone)
out of which many form. NEXRAD does not always detect conditions leading
to smaller tornadoes, but it is highly likely that it will provide warning,
often with many minutes lead time, of most major twisters.
there high tornado frequencies outside of tornado alley?
Tornadoes actually can occur almost anywhere in the nation. And while
the middle part of the county has the largest number, other regions are
far from immune. Though not located in Tornado Alley proper, Harris County,
TX (the Houston area) over the past 20 years has had the greatest chance
of having or one more twister touchdowns. Better reporting has shown that
central Florida has far more tornadoes than once thought. In the past
20 years, 19 maxi tornadoes have struck the U.S. These monster
twisters are at the top of the six point tornado intensity scale (F0 through
F5). Alabama has the distinction of leading the nation in F5-class tornadoes,
reporting four over the last two decades. In any given year, tornadoes
can take detours and strike one area of the nation with unusually
great frequency. Several years ago, Weld County, Colorado, far from Tornado
Alley, had more twisters than any other U.S. county. Most, fortunately,
were weak and short-lived. GO
there seasonal patterns to tornadoes?
The tornado season begins early along the Gulf Coast and before activity
moves northwards with the sun in April and May, some pretty wild weather
can happen. In March 1992, a mobile home was destroyed by a twister near
Zero, Mississippi. Unfortunately nothing unusual there, expect that a
three month old boy was swept away. His father thought his son was gone
forever, only to look up and find the baby hanging upside down from the
branch of a nearby tree. The child was not seriously injured.
tornadoes strike cities in the northern U.S.?
The worst tornado outbreak ever to hit the Twin Cities metropolitan area
in Minnesota occurred on May 6, 1965. The death toll reached 13, and 371
were injured. At least 321 homes were destroyed and 1196 more were damaged.
One of the most spectacular series of tornadoes ever roared through the
Fargo, ND area in 1957. And tornadoes have been spotted well north into
Canada and Alaska.
is the pressure inside a tornado vortex?
No one is sure, except that it is very much lower than that of the surrounding
atmosphere. One recording barometer which survived a near miss by a passing
funnel dipped to around 24.00 inches (your home barometer doesnt
even go that low)
is a gustnado?
The Weather Service doesn't issue gustnado watches or warnings, but such
creatures exist. Formed in the strong wind shears along the gust front
marking the strong outflowing winds at the leading edge of intense thunderstorms,
they look very much like small tornadoes, which in fact they are. While
rather short lived in nature, they can cause F1 scale damage, and sometimes
more. GO TO TOP
is a normal tornado season?
In a "normal" tornado season, about 1000-1100 confirmed twisters
touch down. The average number of fatalities over the past 30 years has
been 82 per season. Often more Americans die from lightning strikes than
was the worst tornado disaster in the world?
The U.S. may have the largest number of tornadoes, but it may have lost
the dubious distinction of hosting the deadliest tornado. A twister struck
about 40 miles north of Dhaka, Bangladesh on 26 April 1989. At least 1109
were killed, 15,000 injured and 100,000 left homeless. Other twisters
have struck that region and may have taken even worse tolls.
is the average path length of a tornado?
In the U.S., the "average" tornado has a path length of about
5 miles and a width of 160-170 yards. The total amount of area involved
in a typical twister is about one square mile. However, the feared maxi-tornado
can exceed many times these numbers.
tornadoes rotate the "wrong way?"
Yes, while the vast majority rotate counterclockwise in the northern hemisphere,
a few percent do spin in the opposite direction. Southern hemisphere tornadoes
naturally do the reverse. Smaller vortices in the atmosphere, such as
dust devils, tend to have a larger percentage spinning clockwise.
do tornadoes sound like?
Witnesses to a tornado often say it sounds like a thousand freight trains
passing. On the other hand, a railroad engineer in Minnesota, who was
involved in a major train collision, said it sounded to him like a thousand
tornadoes. GO TO TOP
following are the contestants for the short distance toss of very heavy
On 7 May 1995 at least
18 people were killed in several Texas twisters, including one man whose
body was found 130 feet away from where he had been standing on the porch
of his mobile home. (In a related tragedy in Dallas, three people were
killed as they were apparently sucked down a manhole by ten foot flood
Severe weather hit
Tazewell County, IL on 9 May 1995. The winds were so strong that a 40
x 80 foot farm building was blown a quarter of a mile across a field.
A tornado, apparently
not of the God-fearing type, struck a church. It ripped off its steeple
and carried it some 15 miles. Another whirlwind sucked up an ice chest
weighing some 800 pounds and transported it over three miles.
A 1973, a Nebraska
tornado struck a house and carried a 500 pound baby grand piano over a
quarter of a mile through the air.
Among the tornado's
favorite tricks is to hurl missiles through the air into other objects.
Pieces of 2x4 lumber though bricks walls and corn cobs driven into telephone
poles are among the more common.
On 10 June 1958, violent
tornadoes struck the area around Eldorado, Kansas. A woman was sucked
through the window of her house and hurled 60 feet. Beside her was a phonograph
record entitled "Stormy Weather".
The Lubbock, Texas
tornado of 1970 was famed for its destructive force. A 41 foot long fertilizer
tank, weighing 13 tons, was blown and/or rolled three quarters of a mile
away from its original position.
Pieces of frozen mattresses
fell from the sky into Boston Harbor on 9 June 1953. These were debris
from the Worcester, MA tornado, some 50 miles away, which struck many
buildings including, it would seem, some furniture stores.
On 7 February 1988,
for no apparent reason, in Lancashire, England the winds, which had been
in the 10-20 mph range, suddenly gusted to 106 mph. The gust tossed a
150 pound sheep feeding trough over 15 feet but otherwise had little impact.
Were not sure this was a tornado, but we wouldnt want to try
to pull the wool over your eyes. GO
debris has been lofted by tornado funnels?
Tornadoes and waterspouts often act rather like a vacuum cleaner, sucking
almost anything from the surface high into the atmosphere. But what goes
up, does come down, and often causing great surprise in the process.
A gentleman living
near London in 1984 heard loud thumping sounds on his roof one night while
watching TV. The next morning he found a half dozen flounders and whitings
up to six inches in length on his roof. Other locals found fish deposited
in their gardens. Either herons fishing the Thames dropping their catch
or the debris from a waterspout were considered likely sources of the
How sweet it is....
On two nights in September, 1857, showers of a candy-like substance fell
from the sky over Lake County, California. Some of the crystals were the
size of a thumbnail, and were collected and turned into confections by
some local residents. With candy prices as they are, too bad we cant
schedule such an event for Valentines Day.
Of mice and men. In
the year 1578, a large number of yellow mice fell from the sky in the
city of Bergen in western Norway.
England there occurred a violent thunderstorm in 1860 in which the heavy
rain became mixed with small, sharp black pebbles. Enough fell in some
places that they had to be swept away.
Pennies from Heaven.
Yes, we do have those, and half pennies, too. They fell out of the sky
near Bristol, England in 1956. Pennies are no big deal in these days of
inflation. But in Germany in 1976, two ministers were surprised to find
some 2000 marks worth of bills fluttering earthward. It was not reported
if they had been praying for money.
Quack, Quack. Ouch....In
Maryland, on 7 January 1969, literally hundreds of badly injured ducks
fell from the sky, apparently having been hurt while in flight. Cause
The smelt run on the
Great Lakes is a spring time fisherpersons delight. But there was
one report in 1986 of smelt literally falling from the sky, by the thousands,
near Alpena, MI. Seagulls were startled too, but not enough to prevent
them from going into a feeding frenzy.
Seashells by the seashore.
But in a shower? Near Stoke-on-Kent, England on 21 March 1983, severe
weather produced numerous weird effects including ball lightning, several
tornadoes, and a shower of seashells from the sky.
Toads. Toads. Toads.
In 1953 the town of Leicester, MA was deluged by a fall of toads. Children
were able to gather them up by the bucketful.
A small boat floundering
in 8 foot waves during a spring storm near Lake Hurons Thunder Bay
had more than capsizing to worry about in 1986. Suddenly thousand of small
silvery fish began falling from the sky like a silver rain. They were
promptly followed by hundreds of very hungry seagulls. Fortunately for
the mariners, they were smelt and not carp. Those big fish can hurt!
Julian Cowan of Brighton,
England was hungry when he was walking though his neighborhood in 1983.
All of a sudden, a 10 inch spider crab dropped out of the sky in front
of him. It was lacking two legs and a claw, and was quite dead. The seafood
was promptly followed by a spate of wind driven hailstones. Though not
commented on by the press, we suspect Mr. Cowan declined to dine on the
air mail delivered delicacy.
There was a thunderstorm
in Charleston, SC on 2 July 1843. Thunder was heard. Rain fell. An alligator
fell. On Anson Street. Really!
Things go better with
coke. OK, but what about the kind that is derived from coal? In England,
after a 1983 thunderstorm, there were numerous reports of chunks of the
carbon, some several inches across, scattered throughout several towns.
Some were found inside melting hailstones.
Heres a free
story idea for Stephen King. In Brazil on 27 August 1968, a shower of
blood and flesh fell from the sky for over five minutes time over an area
of thousands of square yards. Also quite icky was the fall of maggots
during a thunder squall during the 1968 Olympic sailing events offshore
of Acapulco, Mexico. GO
far can tornadoes carry debris?
The Olympic short distance toss contest will be joined by the following
demonstration sport, the long distance debris carrying contest.
Once sucked up into a thunderstorm by a tornado, just how far can some
For hundreds of years
there have been reports of strange objects (fish, turtles, etc.) falling
from the sky, presumably after being lofted by some distant tornado. Now
researchers at the University of Oklahomas School of Meteorology
are interested in receiving such reports as part of a study of severe
storm dynamics. And while falling fish are of interest, reports of items
that can be traced back to their source of origin (canceled checks, pieces
of mail, etc.) are of most value. Recent research has collected a long
list of items which have fallen from the skies, apparently after being
lofted by a tornado. Some of the more interesting things that were gone
with the wind: plate glass, land title papers, a music box, trousers,
coats, a wedding gown, a tie rack, dead ducks, a cow...and an airplane
wing. A jar of pickles was swept away and landed.....25 miles downwind.
And it was unbroken.
On 25 April 1880,
a tornado which went through Noxubee, MI carried an entire bolt of cloth
some 8 miles - without it unraveling.
On 13 June 1953,
Emily McNutt of South Weymouth, MA found a wedding gown in her backyard.
It was dirty but otherwise in good condition. Some detective work traced
the gown back to a woman in Worcester, MA, some 50 miles away. The gown
was just one of the many pieces of debris flung over eastern Massachusetts
by the passage of a powerful tornado.
On 15 April 1979,
canceled checks began fluttering out of the sky in Tulsa, Oklahoma. Their
source: a bank struck by a tornado earlier in the day in Wichita Falls,
Texas. They were carried by the thunderstorm for over 200 miles.
A tornado destroyed
a motel near Broken Bow, OK. The motels sign was later found in
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