University of Illinois Extension
Watch out for Twisters! (Not the movie)
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[July 23, 2024]
At the time I’m writing this, Twisters, the
sequel to the cow-flying film Twister released in 1996, just hit the
movie theatres. Luckily, I didn’t make a spectacle of myself during
the original, shouting out about all the scientific inaccuracies.
While I have not yet seen the new movie, I do want to talk about the
weather of twisters, as in multiple funnels. |
Multiple
vortex tornadoes
When there are very large tornadoes, in some cases a half to even a
mile wide, these are not typically just one funnel, but multiple
funnels. These multiple funnels, the fancy term is suction vortices,
rotate around a central point. Picture a rotating area of air, and
within that, there are much faster rotating columns of air that
follow the larger rotation. You aren’t able to see the individual
vortices because of all the dirt and debris that has been picked up.
These multiple vortex tornadoes are usually associated with
supercell thunderstorms. These nasty storms are already slowly
rotating – yes, the ENTIRE storm is rotating! Within the storm,
rotation can become more concentrated, leading to rotation reaching
the ground.
![](http://archives.lincolndailynews.com/2024/Jul/24/images/ads/current/lcsheriff_sda_HEALTH_2024.png)
The complete mechanism for how this happens is still
not completely understood, but research is getting much closer to
knowing.
The damage path caused by these multiple vortex tornadoes helps
explain something that, in the past, was unexplainable. As one of
these tornadoes travels through a neighborhood, there have been many
instances where some houses are destroyed while others are left with
only minor to moderate damage. If a house is directly hit by one of
these vortices, where the winds may be much greater than 150 miles
per hour, the house may not stand. If a house happens to fall in
between vortices, where the winds may only be 70-90 miles per hour,
there may only be roof and siding damage. [to top of second
column] |
![](http://archives.lincolndailynews.com/2024/Jul/24/images/ads/current/ldn_lda_ALL_010924.png)
Satellite tornadoes
Another type of multiple tornado occurrence is called satellite
tornadoes. These are smaller tornadoes that are separate from a
larger tornado but are part of the general area of rotation. They do
move around the larger tornado, but most of the time, they are
visible as a distinct tornado.
There can also be two close but separate areas of rotation in a
storm that can create what’s called “twin” or “sister” tornadoes,
like the photo paired with this article. While they don’t occur
often, there are several videos of these events that can be seen
online. There was an occurrence of twin tornadoes about a half mile
apart from each other in my home area about 30 years ago.
![](http://archives.lincolndailynews.com/2024/Jul/24/images/ads/current/humanesociety_sda022411.png)
So, while you’re munching your popcorn at the movie
theatre, just enjoy the special effects and try not to get upset
about scientific inaccuracies. I will do the same!
[SOURCE: Duane Friend, State Master
Naturalist Coordinator and Climate Specialist, University of
Illinois Extension]
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