New research finds tornadoes form from the ground up, contrary to popular thought

December 17, 2018 by Lauren Lipuma, American Geophysical Union
A tornado in Galatia, Kansas on 25 May 2012 as it was decaying. Credit: Jana Houser.

New research challenges existing assumptions about how tornadoes form.

Historically, scientists assumed tornado rotation began in , creating a funnel that travels downwards. This theory matches what storm chasers commonly observe visually in the field. Viewers often report seeing funnel clouds gradually descending until they make contact with the ground.

But new research combining a new type of Doppler radar with photos and videos of formed by supercell thunderstorms shows the opposite is true: Tornadoes materialize from the ground up.

Weather forecasters typically issue tornado warnings based on radar observations of strong rotation above the ground, but the new findings suggest forecasters must re-evaluate their warning procedure, according to the researchers.

"We need to reconsider the paradigms that we have to explain tornado formation, and we especially need to communicate this to forecasters who are trying to make warnings and issue warnings," said Jana Houser, a meteorologist at Ohio University in Athens who will present the new findings here today at the American Geophysical Union's Fall Meeting. "You are not going to really ever be finding strong evidence of a tornado descending, so we need to stop making that a priority in our forecasting strategies."

Research conducted in the 1970s suggested tornadoes form from rotation that starts several kilometers above Earth's surface. The theory was that this funnel gradually sucked in air from below, descending until it touched the ground.

Jana Houser standing next to the Rapid X-Pol radar instrument, a new type of rapidly-scanning mobile radar system, during a storm chase on 8 May 2012. Credit: Jana Houser.

Most meteorologists have accepted this theory of tornado formation, but a series of new observations from rapidly scanning radars has started to change that.

One of the pivotal cases contributing to the new understanding of tornado formation occurred on May 31, 2013. On this day, the El Reno tornado formed in central Oklahoma and shattered previous tornado records. It was the widest tornado ever recorded, peaking at 4.2 kilometers (2.6 miles) wide, and had wind speeds of more than 480 kilometers per hour (300 miles per hour), the second-highest wind speeds recorded on Earth.

Houser and a team of researchers from the University of Oklahoma happened to be monitoring the storm with a new type of mobile Doppler radar system that collected tornado wind speeds every 30 seconds. Afterwards, Anton Seimon, a geographer at Appalachian State University in Boone, North Carolina who had chased the El Reno storm, collected hundreds of still photos and videos of the epic twister from citizens and fellow storm chasers.

When Houser compared her with images collected by Seimon, she noticed something odd. The images clearly showed a visible tornado at the ground several minutes before her radar picked it up.

Puzzled, Houser went back through her radar data and analyzed the data taken at the ground. It is typically difficult to get good measurements at or near the ground, but Houser and her team had deployed their instrument on a slight rise and there were no obstructions between them and the tornado, so this time, they had data good enough to work with.

She found clear evidence of rotation at the ground before there was rotation at higher altitudes. Houser then examined other sets of tornado data and found that in many cases, tornado-strength rotation develops at or near the ground first, rather than starting in the cloud itself. In all four datasets she analyzed, none of the tornadoes formed following the classical "top-down" process.

"It emphasizes the fact that we need to have strong, low-level, basically near-ground level , located in the right spot, at the right time, with respect to the larger parent storm circulations in order to form a tornado," Houser said.

Explore further: New study explains creation of deadly California 'firenado'

More information: agu.confex.com/agu/fm18/meetin … app.cgi/Paper/432399

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cantdrive85
1 / 5 (6) Dec 17, 2018
Just as lightning has streamers come up from the ground, so too does the electric discharge phenomena of tornadoes. The above finding should not be a surprise.
cardzeus
4 / 5 (8) Dec 17, 2018
LOL @ 'electric discharge phenomena of tornadoes' You're seriously deluded CD. Why do you bother?
rrwillsj
3 / 5 (2) Dec 17, 2018
Well now cant. This should be easy to prove or disprove your assertion that tornadoes are electrical discharges.

Just produce evidence from neutral sources, such as photos, video, EM damage to conductive items along a tornado's land path.

Yeah? No? No... Testimonials from the barflies you hang out with do not count.

Neither do any of the poorly photoshoped youtube cartoon images all you EU woo cultists claim for evidence.
JaxPavan
3 / 5 (6) Dec 17, 2018
Both critical thinking and criticism require no insults or sarcasm.
rrwillsj
5 / 5 (1) Dec 17, 2018
ph deer max. you've never been to a scholarly symposium? Or observed a scientific debate or grad students brainstorming?

"Okay boys! The whistle is blowing. The artillery barrage, for once, is rolling away from us. the very lights are showing us the direction to the enemy's trenches. We hope? last weeks blunder is best forgptten & necer mentioned. Fix bayonets & follow me! Out of the trenches & across the wire into no-mans land!".

Since there are reiigious prats reading this? I suggest you attend a theology debate of Rabbis or Jesuits. They have some of the best arguments!
mrfixitrick
2.1 / 5 (7) Dec 17, 2018
There is plenty of new science behind the electrical theory of tornados and their formation...

https://agupubs.o...01p00203

http://charles-ch...does.php

https://peter-tho...ado.html
Steelwolf
2 / 5 (4) Dec 18, 2018
Plenty of Old Science and New science overlapping and finding Real Causation.

Remember, these are lightning supercell tornadoes being talked about.

We know that lightning is a matter of neutralizing ground and air charges as they build up.

Near ground air charge can be fairly high and will head to local ground-sink, moving charged air in electric field (storm) heats it so it starts upward movement of air due to charge-heated air rising creating the start of it's own vortex, further increasing the charge current by wind-shear friction and increasing speed of vortex.

That would attract the vortex higher up created from the convergence line of warm and cold air masses creating the supercell storm to begin with.The damage on the ground is the effect of megawatts of electricity being spent kinetically.

Now they have the Proof that it starts at ground level and pulls the vortex down, and they have seen the same repeatedly in other tornadoes.

It really is not woo any more.
Steelwolf
5 / 5 (1) Dec 18, 2018
The link to the article above is very interesting, the links by mrfixitrick show that the idea is actually quite old and was merely put off at some point in time because they had no way of being able to measure the actual current and charge states over the areas required, and it actually took pictures of tornado over water to show the exact dynamics of the shear line effect, the actual 'construction' of the waterspout and allowed them to build working models from that point.

Proof lay in determining, for sure, whether they came top down, sky first, or, as so many had claimed, they saw the whirl on the ground first, then funnel of clouds starts down, and the vortex on the ground 'Leaps up' to the one down-coming. I have seen that effect myself, although I had no explanation for it at the time. I had thought perhaps the upper vortex had sympathetically started the lower one, and they met, but it appears that opposite happens instead.

But the science behind it is real, not woo
Da Schneib
5 / 5 (1) Dec 18, 2018
Having seen dust devils form I have to say that this is consonant with my experience. What will be interesting is *why*.

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