By 5pm Tuesday the death toll in the Joplin, MO tornado was up to
125. This makes it the single deadliest tornado since the National
Weather Service began keeping records of tornadoes back in 1950. This
storm comes on the heels of the 2011 Super Outbreak which occurred on
April 25-27th. On the last
day of the outbreak, April 27, intense storms roared across the South,
killing 336 people (as of May 24th), more than two-thirds of them in
Alabama. That was the single deadliest day for a tornado outbreak since
the National Weather Service began keeping such records in 1950. The 3
day outbreak has been classified by some news outlets as
the second-deadliest tornado outbreak in history, right behind a 1925
outbreak when a reported 747 people died. However, the 1936
Tupelo-Gainesville tornado outbreak is actually in 2nd place with 436
reported deaths. The third deadliest day
had been in March 1932, when 332 people died, all in Alabama, but this
is now replaced with the April outbreak of this year. So the big
question is "why are all these deadly tornadoes happening now when we
have so much technology to help us?"
It's very easy to understand why the
number 1, 2, and 4 deadliest tornado outbreaks are on the list because
they all occurred before the 1940s when we had Doppler radar, tornado
sirens, or even alerts on radio stations. In fact, forecasters
weren't even allowed to mention the words 'tornado possibility' because
they feared widespread panic would ensue. But what about now? We have
Doppler radar, storm chasers, weather radios, tornado sirens, and TV
meteorologists to alert you when there is severe weather in your area.
So how could so many people die with all this advanced technology? Well,
it's really a two part answer: partly strength of the tornadoes, and
partly the locations they hit.
Right now more people live in the southeastern states and central
plains regions than they did in the 1920-1930s. This means that even if
the tornado hits a relatively small area, more people live in that area,
thus more injuries and fatalities could occur. The second part, and
probably more important part is the strength of the tornadoes. Surviving
an EF0, EF1, and EF2 is very likely if you are in a well structured
building, even if it does not have a basement or cellar. However, once
you get to an EF3 you start to notice big structural damage. An EF-3
tornado is strong enough to knock down entire walls of well-constructed
houses, knock over trains, rip the bark from trees and toss heavy
cars. (EF3 damage below).
An EF4 is strong enough to level well-structured brick houses or
sturdy businesses, and rocket cars and other large objects. (EF4 damage
below)
EF-5 tornadoes, while they are the most powerful, also are incredibly
rare. These twisters are strong enough to not only destroy homes, but
blow the debris from them hundreds of feet from their original location.
They can also collapse tall buildings such as hospitals, schools, and
apartment complexes. (EF5 damage below)
So you can see that with fourteen EF4 tornadoes this year and four
EF5 tornadoes this year, strength makes a difference in terms of
survival. In 2010 we had thirteen EF4 tornadoes for the whole year, and
zero EF5 tornadoes. In 2009 we only had two EF4 tornadoes and no EF5's.
In fact, the last time there even was an EF5 tornado was in 2008, and
there was only 1. Strength makes a huge difference. Think of
earthquakes. A magnitude 6.0 is way difference than a magnitude 8.0
earthquake. An 8.0 is actually 20 times stronger than a 6.0 not just 2
times more powerful like you would think. While the scale difference is
not the same for tornadoes, the implication that an EF5 will do a
significantly greater amount of damage than an EF4 is correct.
The moral of the story is to be prepared, know your safety plan in
advance, and just know that no matter how much technology we have,
meteorologists can't be certain whether a tornado will become an EF2 or
an EF5 before it touches down, so prepare for the worst.
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