How do tornadoes form?

Much of the photos and video courtesy Andrew Pritchard and used with permission.

[xyzct]

Skip's a real storm chaser. Even his hair has a strong updraft.

[mikeysan]

Skip, you are truly one of the gifts to those interested in tornadoes. The breakdown of the El Reno storm was phenomenal. Keep up the excellent work, including any new details or information regarding tornadogenesis.

[Strothy]

you and hank both are my fav. youtube storm chaser! let's hope for a healthy and not so devastating 2019!

[Joesfosterdogs]

LOVE your no nonsense style...just the facts...not stupid personality attempts to gain a following...you're a true educator! Your Go South video was stellar...epic knowledge.

[dktommyboy]

Love your videos. Like your style. This is a good explanation for those curious.

[SmokeTheHolyChalice]

Do yourself a favor and watch this man in field chasing. There’s a reason he is in the top tier of chasers, getting some of the best footage of tornadoes in existence while simultaneously keeping himself and those around him safe to chase again. Yes, his incredible deep knowledge of supercells and tornadoes, in addition to his extensive experience chasing, plays a major role in how he achieves this. However, I swear there is an art to it and something intangible that a few people have that differentiates the proficient chaser from the truly proficient chaser and the elite. Part of a select class of chasers that are so damn good at what they do that others are willing to literally put their lives in his hands as if it’s the most natural and obvious thing in the world. Think about their lives! How many people do you know who you have absolute confidence in their abilities to the extent that you would be willing to bet your life on it? Yeah, me either.

[StormChasersofOhio]

We saw a convincing example of this on August 9th, 2021. The Sycamore EF1 can be seen developing strong vortices on the ground before the funnel fully condenses. Video on our channel

[charlesmaeger]

Skip, I realize you can't get too technical. Explaining in more detail how this upward vorticity (at the very beginning) starts to form. I've heard there are two intersecting columns of air that are flowing against each other at ground level. Can you explain in more detail how this upward vorticity starts and increases in strength?

[emcity]

I think your analysis combined with Dr Leigh Orf's computer generated models are at the forefront on developing a complete understanding of tornado genesis. When you mentioned the two downdrafts (FFD and RFD) beginning to squeeze the warm inflow surface jet, that points to Bernoulli's Principle -how water pressure and speed increase as a channel narrows. This principle can also be applied to air as it's how an airplane wing generates lift. I think Dr. Orf's Streamwise Vorticity Current (SVC) depicts the inflow and the tornado is a byproduct of that inflow surge. As the pressure falls from the inflow surge, an aggregation of cyclonic and anti cyclonic inflow vorticity at the surface consolidates and stretches into that surging rotating updraft using Conservation of Angular Momentum like you said and voila..tornado. It could also be an increase in 500mb winds that push the updraft down shear aloft and that surges the inflow. There are so many factors and varieties of tornadoes in size, strength and duration it seems no one "trigger" ingredient is responsible for the creation every time. And the vortexes here on Earth are simplistically tame compared Saturn's hexagon polar vortex and Jupiter has a massive vortex cluster on its poles. Probably lots of math involved.

[kevinashley]

1:09 I know that everyone has seen what I'm about to describe, so I hope I am clear. This ground level vorticity that you speak of here, is it the same thing that we see on a windy day in fall, when the wind whips leaves in a circular fashion? They always remind me of little tornadoes, obviously an extremely weak version, and they only spin the leaves around for a few seconds.

[TEMPESTGALLERY]

Well done Skip! I never don't learn something from your

[sammylacks]

Skip thanks for sharing. I have been able to learn much and questions answered from your observations and knowledge. I ve noticed how often you go with your feelings and experiences regardless of others decisions. Then you speak about your observations on formation and sustainability issues within the storm and even if time or another person finds reasons to prove any part of your finds incorrect I can only respect your commitment and self confidence.
Thanks so much for taking so many like myself as close and safely as possible where we d never get the chance to and learn what I have.
Be safe.
I wrote comment before watching this video. I'd to thank you for answering a question I ve had and all the looking and digging never provided and answer I understand and felt made sense.That was how tornados form in non.supercell storms. Here in coastal NC we see multi cell storms and only get supercells to my knowledge on rare occasions. I d just about decided any tornados NC has had that lasted long enough to even be confirmed were.spawned from supercells embedded in fronts or tropical storms we get IE hurricanes.

[Master_RoSSShi]

Skip I have a question for you, maybe not related to the video:


Is it possible for a Ghost Train to form without a tornado in progress? I was storm chasing Sunday and was escaping south from a rotating wall cloud. We noticed what looked like a ghost train. It was almost exactly how you described in previous videos, but no tornado was present. I know this is true because the time our video was at was before the NWS recorded time of the touchdown. What do you think? I can always email you a very poor quality video still if that will help too.

[moelester]

Another awesome video skip...keep them

[warpdriveby]

Great presentation, our understanding is really growing! I got to see a talk by a professor stydying tornadogenesis at UW Madison when I went back to visit one of my professors who still teaches there. It seemed to me like the models implied that a conjunction of things including those you cover are needed, and the more of them and greater their amplitude, the worse and more numerous dangerous tornadoes are. The models seem emphatic that what appears to be a single vortex, even in landspout types is a braid of woven sub-vorticies. I think we also split the atmosphere into layers with sharper boundaries than generally exist. I think vortex generation and aggregation along a strong boundary and the rotating updraft/windshear conditions seem necessary together and additive but also don't cause or impede each other. It really looks like a number of mostly/semi independent conditions are required, and then some particular initiating condition emerges. The which way will a water droplet run down a surface experiments seem to suggest we can know roughly when one will occur and how large it's like to be, but predicting one to the second and foot may be fundamentally impossible?

[humansrants]

I wonder if this can be tested in Blender Mantaflow.

[Jack-tdhl]

If tornados form from the ground up, I’m curious what your take is on why funnel clouds appear to descend from the cloud. Is it that rotation is already on the ground, but is not yet strong enough to be noticed? And as the rotation increases, the funnel condenses closer towards the ground?

[josephstalin]

what if every supercell has a tornado? I mean if the mesocyclone draws in all the RFD, FFD and inflow that create rotation that then gets streched, what if there is always a tornado, just the updraft or rotation are too weak to be noticable.

[Atka]

That's close enough, keep spreading the insight and eventually lives and property will be saved. Just remember to include that tornados are harvesting energy that grows on the fields below; the inflow energy is converted and stored in horizontal vortices by frictional ground effect, this rotation rushes toward the low pressure point of updraft that in turn transfers that energy to vertical rotation when sucked up. Ground level obstructions diffuse the energy by collapsing the inrushing vortices by infusing chaotic flux into their closed systems. However once the tornado is wound up it no longer requires the ground based energy; inertia mixed with updraft energy will carry the tornado forward.
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[mizzaely]

If the meso is driving and organizing/collecting all the little vortices. Doesnt that mean tornados spawn at both ends?