- Approximately 1,000 tornadoes hit the
United States every year. In fact, within the last few hours at least
twenty tornadoes touched down in the American South [and no, this is NOT
normal]. CNN reports that
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- At least two tornadoes ripped through
the heart of Nashville Thursday afternoon, April 16, damaging at least
300 buildings, including the State Capitol, and injuring more than 100
people.
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- Despite a path of damage six miles long,
the only reported fatalities were two people killed in car crashes believed
to be related to the storm.
-
- [quoted from http://cnn.com/WEATHER/9804/16/nashville.tornado.4/
index.html]
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- Unfortunately, the folks living in the
bedroom communities surrounding Birmingham, Alabama, weren't so lucky.
On April 8th, three tornadoes moved across central Alabama, killing 33
people and injuring over 200. The largest of the three tornadoes was rated
as an F5, the most violent tornado that occurs.
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- THE FUJITA SCALE
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- Tornadoes are measured using a scale
that measures the amount of damage the tornado causes. The scale is known
as the "Fujita Tornado Intensity Scale":
-
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- F0 (Gale tornado) 40-72 mph
Some damage to chimneys; breaks branches off trees; pushes over shallow-rooted
trees; damages sign boards.
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- F1 (Moderate tornado) 73-112 mph
The lower limit is the beginning of hurricane wind speed; peels surface
off roofs; mobile homes pushed off foundations or overturned; moving autos
pushed off the roads; attached garages may be destroyed.
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- F2 (Significant tornado) 113-157
mph Considerable damage. Roofs torn off frame houses; mobile homes demolished;
boxcars pushed over; large trees snapped or uprooted; light object missiles
generated.
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- F3 (Severe tornado) 158-206
mph Roof and some walls torn off well constructed houses; trains overturned;
most trees in forest uprooted
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- F4 (Devastating tornado) 207-260
mph Well-constructed houses leveled; structures with weak foundations blown
off some distance; cars thrown and large missiles generated.
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- F5 (Incredible tornado) 261-318
mph Strong frame houses lifted off foundations and carried considerable
distances to disintegrate; automobile sized missiles fly through the air
in excess of 100 meters; trees debarked; steel reinforced concrete structures
badly damaged.
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- F6 (Inconceivable tornado) 319-379
mph These winds are very unlikely. The small area of damage they might
produce would probably not be recognizable along with the mess produced
by F4 and F5 wind that would surround the F6 winds. Missiles, such as cars
and refrigerators would do serious secondary damage that could not be directly
identified as F6 damage. If this level is ever achieved, evidence for it
might only be found in some manner of ground swirl pattern, for it may
never be identifiable through engineering studies
-
- [quoted from http://www.tornadoproject.com/fujitascale/
fscale.htm#top]
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- Between 1950 and 1994, 74% of all of
the tornadoes that touched down in the United States were "weak"
(F0 or F1), 25% were "strong" (F2 or F3), and only 1% were "violent"
(F4 or F5). In fact, growing up in Oklahoma, I remember learning in school
that there were only one or two F5 tornadoes in the United States each
year.
-
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- THE ALABAMA TORNADOES
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- Of the three tornadoes that touched down
in Alabama on April 8th, one was an F2, one was an F3, and one was an F5.
The National Weather Service Office in Birmingham has issued a preliminary
report on all three of these tornadoes at http://www.acesag.auburn.edu/department/nws/april_08_1998/april_08_1998.html
-
-
- This page describes what happened during
each of the three tornadoes, shows you the path that each tornado took,
and gives you pictures of both the damage and the radar images caused by
these tornadoes. I would _strongly_ recommend that you take a look at
the path that the F5 tornado took. You can do this by either clicking
on the F5 portion of the map on this page, or pointing your Web browser
to http://www.acesag.auburn.edu/department/nws/april_08_1998/oakgrove.jpg
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- This image will take a little while to
load (it is 427 K!), but it shows you the entire path of the F5 tornado
from its touchdown to its end. Fortunately, this tornado traveled through
sparsely populated areas. However, take a look at this image and imagine
what would have happened if this tornado had come in just a few miles to
the south (the black line on the image is the tornado's path, and downtown
Birmingham is in the upper right corner of the image, at the intersection
of Interstates 65 and 20).
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- PROTECTING YOURSELF
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- Unfortunately, tornadoes aren't limited
solely to the United States. In fact, Australia has the second highest
incidence of tornadoes, and hundreds of other countries around the world
experience tornadoes every year. So how can you protect yourself?
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- If you are at home when a tornado is
sighted:
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- * Go at once to the basement, storm cellar,
or the lowest level of the building.
-
- * If there is no basement, go to an inner
hallway or a smaller inner room without windows, such as a bathroom or
closet. Get away from the windows. [When I was a kid in Oklahoma, we
were taught to open all windows to "equalize the pressure."
It turns out that the only thing that this does is get your carpet wet.
In other words, KEEP YOUR WINDOWS CLOSED ... and STAY AWAY FROM THEM!]
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- * Go to the center of the room. Stay
away from corners because they tend to attract debris.
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- * Get under a piece of sturdy furniture
such as a workbench or heavy table or desk and hold on to it.
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- * Use arms to protect head and neck.
[Remember all those movies where the airplane is about to crash and everyone
is told to "assume crash positions?" That's what you need to
do.]
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- * If in a mobile home, get out and find
shelter elsewhere. [It sounds silly, but you'll be a heck of a lot safer
lying outside in a soggy ditch.]
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- All of these tips come from the United
States Federal Emergency Management Agency's Tornado fact sheet: http://www.fema.gov/fema/tornadof.html
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- READ THIS WEB PAGE! PRINT IT OUT! This
page tells you what to do before, during, and after a tornado, as well
as what you should do if you are caught in a tornado at work or school,
outdoors, or in a car. We don't pull our little bus of Internet happiness
into too many Web sites that can save your life. This one can. Read it.
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- THE UNSUNG HEROES
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- In most parts of the world, people depend
on their local television weather centers for tomorrow's forecast. Most
weather centers are staffed with weatherpeople who are usually just newsreaders,
people hired to read the weather each night but who have no formal training
in meteorology. Heck, late night talk show host (and former host of the
Academy Awards) David Letterman used to be a weatherperson.
-
- In my part of the world, we depend on
our local television weather centers with our _lives_ (after all, we just
had 20 tornadoes in the past couple of hours). That's why most of the
local television stations in the south -- most of the GOOD stations at
least -- invest millions of dollars in the latest high-tech weather forecasting
equipment. To man this equipment, the stations hire the best meteorologists
in the world. In my humble opinion, two of the best are James Spann and
Dan Satterfield.
-
- James Spann is the chief meteorologist
at ABC 33/40 in Birmingham (actually, he's one of THREE full-time meteorologists
at 33/40). When severe weather threatened Alabama both on April 8th and
earlier tonight, Spann went on the television (and on several Birmingham
radio stations) and stayed on the air, live, non-stop, 5 or 6 hours, no
commercials, until the danger passed. Spann used ABC 33/40's Pinpoint
Doppler Radar to show his audience which _neighborhoods_ (and, in some
cases, which streets) were effected by the storms, giving people in the
path of the tornadoes as much as 15 or 20 minutes advance warning before
the tornadoes struck.
-
- Spann (and the rest of the ABC 33/40
weather center) saved countless lives over the past couple of days. For
that, I thank him. In fact, I figured I'd pull our bus into one of his
Web pages to show my appreciation. If you are interested in seeing some
of Spann's favorite Web sites, take a look at his "Favorite Links"
page at http://www.abc3340.com/weather/links.html
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- While James Spann covers central Alabama,
Dan Satterfield covers north Alabama. Satterfield is chief meteorologist
at WHNT in Huntsville, Alabama, and is the only lead weather anchor in
the Tennessee Valley with a degree in Meteorology (he graduated from the
University of Oklahoma and was on the tornado intercept team at the National
Severe Storms Lab (the movie "Twister" was loosely based on the
work done by Satterfield and the other folks at the NSSL)). Like Spann,
Satterfield also stayed on the air nonstop to cover both tonight's tornadoes
and the ones on April 8th. In fact, because most of tonight's tornadoes
were located in Tennessee (and because part of Satterfield's audience lives
in southern Tennessee), most everyone in northern Alabama and southern
Tennessee turned to Satterfield for the latest information about the storms.
[My family lives in the Tennessee Valley, so most of my night was spent
on the phone with my family, listening to Satterfield's reports.]
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- I guess I had better find a way to thank
Satterfield as well. Since a number of our TOURBUS riders are either teachers
or parents, I'd highly recommend visiting Dan Satterfield's "Wild
Wild Weather Page" at http://www.whnt19.com/kidwx/index.html
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- This page is an absolutely WONDERFUL
interactive weather page for kids, and it explains everything from El Nino
to wind. I particularly recommend his "tornado" page that explains
tornadoes in terms that even I can understand.
-
- ... now if only I could convince Spann
and Satterfield to put the video of their forecasts on the Net, _everyone_
would see how lucky we Alabamians are to have two of the best meteorologists
in the world watching out for us. :)
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