After reading that stuff from NWS, and a few other sources, the way I imagine it is that once fully developed, the rapid, concentrated updraft converges near the surface, at the vortex. The downdrafts are peripheral, surrounding the vortex. As a glider pilot, you know that where there is rising air there is also descending air nearby, a sort of displacement reaction. Perhaps the surrounding downdrafts of a tornado, under this supercell TS, both contribute to and are perpetuated by the updrafting vortex.

Also, it seems (from what has been written) that tornadoes occur mostly during the mature stage of TS when convection is strongest, and what you are describing is the dissipating stage, characterized by downdraft and divergence.

Fascinating stuff. Here's a little better photo with description of the original post "dusty." I can tell you that would want no part of flying airplanes on that day.

EZFlap wrote:I admit I do not have the scientific or field training to argue with the NWS. There are indeed some sharp folks who study this stuff all day. However, if I happened to be standing next to a NWS tornado researcher, I'd ask the following question:

1) We know that tornadoes develop because warm air and moisture rise up high, cool off, and sink back down violently. We know for sure that this phenomenon is the overall "engine" or energy source for the tornado. So the air must rise up first, essentially storing potential energy, "charging up" the storm.

2) Then a heat release or heat exchange occurs. This triggers the release of all that stored energy. I think we know that for sure too.

3) Then the energy is released, and this entire cold wet airmass comes down like an avalanche.

So the big question in my mind is... if the tornado is indeed an updraft (as the NWS quote indicates), then how could any significant updraft possibly form in the face of that enormous downward avalanche of air? The heat/rising cycle has already been completed by the time the cold wet air starts falling. This sounds like something along the lines of a surfer being able to surf against (and burst through) a pretty large tsunami to me.

If Mark Grubb is still reading this forum thread, I believe he is in a position to ask the opinion of two very qualified experts about this (Walt Rogers and Dan Gudgel). They are both highly qualified aviation weather types, and both have a large number of hours in small aircraft.

EZFLAP...the downdrafts (cold air) usually preceed the storm as a large downward blast of air..this blows up a lot of dirt before the rain, then comes the rain, and possibly hail (but not in every case), then comes the tornado..usually at the back edge of the cloud (but not always). Remember what started this phenomina is the rising warm air that produces the cloud as the warm moist air passes the dewpoint. When moisture in the cloud gets heavier than the updraft, it produces rain. If the updraft is very strong, it pushes the moisture even higher, longer and that produces hail when the updraft can no longer hold it aloft and down it comes, cold air and all. So what you have is a storm with updrafts and downdrafts and circular motion and when the whole mess gets violent enough it will produce rain, high winds on the ground, hail, and tornados. I have always been facinated with thunder storms and have probably seen 100 tornados and they are all different but when you see one, especially if you are close, you have no doupt what they are. In June of '99 I watched a small storm develope into a monster within about 20 minutes..baseball sized hail, 80mph wonds for 20 minutes..did $40,000 damage to my house. I went out and took videos as it was approaching and this cloud was dark as night. When it hit, it was pitch back outside while the hail shook the house..we later determined from the damage a tornado had hit about a quarter mile from my house. I don't have to read about severe weather on the plains, I've lived through it most of my life. If anybody would like to witness it first hand, spend some time in tornado alley..it will make a believer out of you!

HiC,
I had to come read your post as it relates to some of the weather watching we discussed. You gave a very good description of what happens. We get some big ones here too, we lost the whole town of Spencer SD in '98 and then Manchester in '03 but the most famous tornado description ever was by a man who once lived close by in Aberdeen. His name was Frank Baum.
To this day I'm still scared of tornadoes.

This is what happens when ya fly through a dust devil in a Ford Tri Motor...

Just say no.

Aside from the obvious weather problems, consider the damage the sand blasting will do to your paint, fabric, aluminum, windscreen, etc. Now think about that air filter... what happens if that gets plugged up?

I came across this after watching Zane's "Fuselage not required"

http://www.youtube.com/watch?v=2iBjqFJsraM

Student BCP wrote::shock: I came across this after watching Zane's "Fuselage not required"

http://www.youtube.com/watch?v=2iBjqFJsraM

What service! The dust devil comes to you! Looked like it could have set them back down on their heads. That looked scarier to me than the zip line video.

tom