2018-10-21 EVENT: AZ

[JamesCaruso]

https://stormtrack.org/community/threads/2018-10-21-reports-az.30448/

That’s really awesome Jeremy, congrats! Beautiful shots! You mentioned cellphone video at one point in your post, were all of those photos/videos taken on a cellphone camera? I wouldn’t think so, especially that zoomed in shot as most cellphone cameras don’t have powerful zoom capability but just wondering. Thanks and congrats again, nice treat to hold you over until spring!

 

[Ethan Schisler]

Wow incredible shots! I know this is for reports only, but in my opinion, your photos are contender for some of the *prettiest* tornado shots of 2018. That red debris cloud near the surface is amazing.

 

[Warren Faidley]

Great shot. That day had some potential no doubt.

 

[Jeremy Perez]

Jim, Ethan, Warren, thanks! I've been hindsight critiquing the location I picked for those shots, but so much went right with it that it helped make up for my hurried choices—especially that iron rich dirt it was lofting. Just a beautiful thing.

Jim, I started with cell phone video on the interstate while I was still trying to find a spot (first two video frame grabs up above). Once I stopped, I switched to the DSLRs and a better video camera. You're totally right, zoomed shots would've been terrible from the cell phone.

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@JamesCaruso @Ethan Schisler @Warren Faidley

 

[Dan Robinson]

This is an official EVENT thread for the remarkable Arizona landspout on October 21 of which Jeremy Perez captured some excellent imagery. His report is here:

https://stormtrack.org/community/threads/2018-10-21-reports-az.30448/

 

[Jeremy Perez]

Some of the setup info.

Bulk shear out of the of 30 kts and CAPE of 1000+ j/kg was what had me interested in storm strength and possible brief structure. On days with SW mean flow, the MRCZ will set up with SE surface flow, so brief rotation and transient supercell structure can be fun to photograph over whatever cool terrain is out there.


Landspout possibility is always on my mind out there. 0-3km lapse rates around 8.5C/km were heartening. I also had an eye on RAP surface vorticity which was floating a bullseye around Winslow. I only recently became aware of that plot, so I’m not sure how valid it is for incorporating into all the options. Despite those, higher shear had me doubting landspout possibilities. And non-supercell tornado parameter that afternoon was not impressed either. Enhanced Stretching Potential however, did hold out some hope.








The sturdy convergence boundary that was in play started out with a notable cusp that was favoring convective initiation. Once the storm of interest got going, it seemed to reinforce the west side of that cleft. Whether that additional reinforcement aided vorticity for the landspout or was superfluous to it, I have no idea. The image below is about an hour and ten minutes before the landspout spun up and the southern edge of the updraft was up to the interstate by then.


A mental glitch that goofed up my urgency was seeing the storm drifting pretty far north of the boundary. I got in a Plains warm front frame of mind, e.g., cell getting too far north of the ‘warm sector’ to do well. Stupid. Convergence boundary, not baroclinic. Still, it’s interesting to see how well it managed to benefit from vorticity off that boundary as far removed as it was getting.

 

[Warren Faidley]

Jim, Ethan, Warren, thanks! I've been hindsight critiquing the location I picked for those shots, but so much went right with it that it helped make up for my hurried choices—especially that iron rich dirt it was lofting. Just a beautiful thing.

Jim, I started with cell phone video on the interstate while I was still trying to find a spot (first two video frame grabs up above). Once I stopped, I switched to the DSLRs and a better video camera. You're totally right, zoomed shots would've been terrible from the cell phone.

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@JamesCaruso @Ethan Schisler @Warren Faidley

I briefly looked over the forecast that morning and joked to my wife that there was going to be a tornado later near Flagstaff. That is a long drive from Tucson. I think if the shear had been a tad higher I might have chased.

 

[Jeremy Perez]

I briefly looked over the forecast that morning and joked to my wife that there was going to be a tornado later near Flagstaff. That is a long drive from Tucson. I think if the shear had been a tad higher I might have chased.

I was thinking after that happened, if I lived in Phoenix or further out, I probably wouldn't have wagered the time and travel either. Which means I don't often venture south of Casa Grande/Gila Bend for the inverted trough fun you guys seem to get more often down there.