08/13/08 DISC: CO

[Mark Farnik]

Aaargh! I was in my Digital Lab Techniques class at the time and watched the storm go up and intensify on radar as it interacted with that boundary. I wanted to go after it, but I was stuck in class until 4:30. And by the time I took the bus to the Broadway station and the light rail to where I parked my car at the Park 'N' Ride at Colorado and I-25, the storm was already halfway to Kansas.

I'm jealous, not gonna lie, but what an awesomely unexpected catch for an August afternoon!
A hearty congratulations on your first tube, Dann! May it be the first of many!

 

[Matthew Grzych]

Great shots Dann! What beautiful structure from your vantage point. This storm was definitely a compact LP supercell. That's why all the action and rotation was displaced so far west from the core and really no hook showed up on radar. The Platteville profiler was showing 60-70 kt of upper level winds and since the storm was nearly stationary, the anvil level flow was probably 60-70 kt. Anytime the anvil level flow is 60+ kt, you'd expect to see LP storms. Your video grab also shows a mini RFD notch coming in from the west. I was actually just under and west of the small base when a small scale RFD surge blasted me and tightly wound up into a dust whirl within a few hundred yards of me a few minutes prior to the tornado. It picked up gravel off the road and got me. The gust of winds was warm and probably dynamically forced. It was definitely a very cool storm and probably kind of rare to get a tornadic LP supercell. Although, I've seen a couple in CO and KS similar to this.. this one was much smaller scale than the others.

 

[Dann Cianca]

Great shots Dann! What beautiful structure from your vantage point. This storm was definitely a compact LP supercell. That's why all the action and rotation was displaced so far west from the core and really no hook showed up on radar. The Platteville profiler was showing 60-70 kt of upper level winds and since the storm was nearly stationary, the anvil level flow was probably 60-70 kt. Anytime the anvil level flow is 60+ kt, you'd expect to see LP storms. Your video grab also shows a mini RFD notch coming in from the west. I was actually just under and west of the small base when a small scale RFD surge blasted me and tightly wound up into a dust whirl within a few hundred yards of me a few minutes prior to the tornado. It picked up gravel off the road and got me. The gust of winds was warm and probably dynamically forced. It was definitely a very cool storm and probably kind of rare to get a tornadic LP supercell. Although, I've seen a couple in CO and KS similar to this.. this one was much smaller scale than the others.

Thanks Matt, your shots are great too ... especially from a phone! Awesome to see it from the other side ... great perspective.



...


Also, just to clear things up from a couple blog comments that I've read, this tornado was NOT a landspout. Well, unless landspouts form out of the center of a wall cloud. I think Matt can verify this, yes?


Dann.

 

[Matthew Grzych]

Sometimes its difficult to distinguish landspouts from supercell tornadoes in dry environments and on the High Plains. I'm almost 100% sure that this tornado was a supercell tornado and not a landspout especially after seeing Dann's shots of the updraft region. Here's why I think it was a supercell tornado:

1. A parent mesocyclone was present visually for close to an hour prior to tornadogenesis (at cloud base and extending into updraft).
2. There was a very distinct mesocyclone signature on radar.
3. There was an RFD notch visible at cloud base.
4. I witnessed an RFD type wind gust under the cloud base about 5 minutes before tornado.
5. Dann's photo's clealy show LP supercell structure.


Visually, the tube may have looked like a landspout, but the other dynamics where there to support the idea that this was a supercell tornado.


Matt