Phoenix Chase 2/22

[Joe Zemek]

Re: Joe Zemek's Arizona storm pics

Originally posted by joel ewing
Hi Joe, this is Joel in Tucson (no, we've never met). I was looking at the 5 photos you took of the recent Arizona action, and noticed something in pic #4. I'm referring to what appear to be at least one \"tube\" of sorts..which, as you're looking at the photo....juts out and down to the left from the extreme left side of the storm's base. I wonder if your camera saw something that perhaps you did not see with your naked eye. Lemme know what you think you've got there. Thanks...Joel

I think that's really more RFD stretching the precip, tho I don't remember seeing it at the time (being focused on the wallcloud rotation and development). I looked at some other nonposted shots and couldn't find any tubes extending from the wallcloud, though there was evidence of the sort of downdraft-induced horizontal tube that you can sometimes see manifest in scud motion in the RFD area.

 

[Chuck Vlcek]

Re: Arizona action

Susan Strom wrote:

WHAT is it about road, it's like the Bermuda Triangle for storms.

I think it has something to do with how the atmosphere interacts with the local topography. You can get local terrain-induced convergence zones and local enhancement of low-level helicity. I'm not that familiar with Arizona topography in detail, but somebody might like to try a mesoscale analysis though data might be a bit sparse. Time-lapse photography might provide a few clues.

 

[Susan Strom]

Chuck, the atmosphere most definitely interacts with the local topography here, and also on the outflow boundaries that result from earlier storms at higher elevations. The terrain here is shall we say, "tweaked", by Arizona's volcanic track record that created the sharp canyons and dramatic mesas. My guess is that storms fire on that road not only due orographic lift but also proximity away from urban heat islands (there's nothing out there near Congress/Yarnell). However, Arizona is a big place. Why that one highway in particular, a relatively small area, always seems to fire is beyond me. Not that I'm complaining