question on cloud base vs. updraft rotation

Hey guys,

I've noticed one incredible thing on the movie of LP supercell Oscar van der Velde posted in one thread few days ago. Here is the video:

http://www.lightningwizard.com/Anim...,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86

Now look at the rotations of cloud base and main updraft. I've seen this video long time ago, but haven't noticed that rotations are actually the opposite ones. The cloud base is rotating clockwise while the updraft is rotating counterclockwise.

There is a classic updraft rotation caused by quite strong wind shear, but my question is what causes the cloud base rotation in the opposite in this case?

Other question would be how anticyclonic tornado forms? Does the cloud base rotation play a big role there or the main rotation always belongs to updraft rotation?

Thanks for any answers, I would really appreciate it if someone could explain it physically.

Marko
 
Hey Marko :)

I feel that it can vary between storms, as reguards the rotational directions in both loud base and in the main storm structure itself :)

It has been known that an entire supercell may rotate clockwise (Anticyclonic), but occasionally also, it can happen, that a supercell as to opposite rotational directions in the same storm, and I feel that it there are many factors that can cause this and I think that it can depend on the direction of the storm's inflow direction, at cloud base level, but really it's just as guess as I said there may be many other factors that would cause the rotational opposites :)

I have done many tornado experiments with the tornado machine that I have, and even with a cyclonic set up, I have still known tornadoes to occasionally spin in a clockwise direction, and I feel that, it's a case of the winds have more rotation momentum in a anticyclonic direction, than in the cyclonic, kinda like a tug of war between going left and going right, in where going left wins the war on occasion :), but as I said before, there may be other factors involved in the reason for this and so, I am very open minded as the reasons for this :)

I hope that this is of some help at least, in some way or another :)

Willie
 
What you have to remember is that the portion of the storm nearest the camera is on the right hand side (relative to the storm's motion) of the RFD...so you have anticyclonic vorticity there, and cyclonic vorticity on the other side of the updraught (not visible).
 
Hey guys,

I've noticed one incredible thing on the movie of LP supercell Oscar van der Velde posted in one thread few days ago. Here is the video:

http://www.lightningwizard.com/Anim...,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86

Now look at the rotations of cloud base and main updraft. I've seen this video long time ago, but haven't noticed that rotations are actually the opposite ones. The cloud base is rotating clockwise while the updraft is rotating counterclockwise.

There is a classic updraft rotation caused by quite strong wind shear, but my question is what causes the cloud base rotation in the opposite in this case?

Other question would be how anticyclonic tornado forms? Does the cloud base rotation play a big role there or the main rotation always belongs to updraft rotation?

Thanks for any answers, I would really appreciate it if someone could explain it physically.

Marko

I witnessed this on May 29, 2004 near Medicine Lodge KS. The bottom of the storm was anticyclonic while the mid-top parts were cyclonic in rotation. Also, on March 29, 2005 a left split in North Carolina showed this behavior on radar. As far as physical answers, ???
 
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