2013-05-31 EVENT: KS, OK, MO, IL

[JamesCaruso]

That was an incredibly intense video. I wonder why it took nearly seven years for him to post? (Wow, can’t believe it has been that long...)

I was not there, have not watched any El Reno video for years now, and am unsure where the storm was in its evolution during this video, so I have a couple questions. That first circulation that appears to have crossed to the east side of 81 at a little over 9 minutes - was that what ultimately became the main tornado / wedge, or was that a satellite? Then when they were facing into the debris field, was that the edge of the main circulation / RFD (which I know in this case essentially was part of the tornado) or was that a satellite circulation they were in?

Can’t imagine it was too smart to face into the debris, I know they didn’t want the car to roll but they were risking serious injury from a smashed windshield. They would have been better off facing the back of the car into it, at least they would be further away from the glass and not getting it in their faces

Good to have some activity on this thread after so long, still the most fascinating event in my opinion, despite the more recent SLT incident, which is interesting for the chaser impact but in my opinion El Reno is far more meteorologicalically interesting, both for the storm itself and the conditions that gave rise to it.

 

[Paul Knightley]

James - the first circulation - I believe this was the circulation which pushed Bettes off the road - I'm not sure if it was the suction vortex which went on to the Twistex crew - perhaps @Skip Talbot could comment as he's undertaken an extensive analysis, with others. Overall, though, I think you might class it as suction vortex, as opposed to the 'main' tornado - for much of the period following that crossing the highway they are within the broader tornadic circulation.

The second part, with debris - I *think* this is another embedded suction vortex/whatever it might be classed as - it was around this time the tornado was really expanding too - you can see when they then face NE that the whole mass has, effectively, cloud material at ground level, which it didn't a few mins earlier before it crossed 81.

 

[James K]

@Dan Robinson:
Whoa that's a pretty intense vid!

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I went back & read through the whole thread (since it was posted well before I ever joined here)...and just .wow. reading it. Its all like a bit of history saved right here on ST.
Kinda sad that some of the pic's & links no longer work tho.

 

[Paul Knightley]

@Dan Robinson:
Whoa that's a pretty intense vid!

---
I went back & read through the whole thread (since it was posted well before I ever joined here)...and just .wow. reading it. Its all like a bit of history saved right here on ST.
Kinda sad that some of the pic's & links no longer work tho.

If you fancy a read of our chase experience, with a few pics, feel free to have a look at May 31st report

 

[Skip Talbot]

That was an incredibly intense video. I wonder why it took nearly seven years for him to post? (Wow, can’t believe it has been that long...)

I was not there, have not watched any El Reno video for years now, and am unsure where the storm was in its evolution during this video, so I have a couple questions. That first circulation that appears to have crossed to the east side of 81 at a little over 9 minutes - was that what ultimately became the main tornado / wedge, or was that a satellite? Then when they were facing into the debris field, was that the edge of the main circulation / RFD (which I know in this case essentially was part of the tornado) or was that a satellite circulation they were in?

Can’t imagine it was too smart to face into the debris, I know they didn’t want the car to roll but they were risking serious injury from a smashed windshield. They would have been better off facing the back of the car into it, at least they would be further away from the glass and not getting it in their faces

Good to have some activity on this thread after so long, still the most fascinating event in my opinion, despite the more recent SLT incident, which is interesting for the chaser impact but in my opinion El Reno is far more meteorologicalically interesting, both for the storm itself and the conditions that gave rise to it.

Allan Gwyn's shots were hugely helpful for the crowd sourced El Reno Survey project. They've been up there for years, but yes, I believe he just now also posted them to YouTube.

The vortex crossing 81 is almost surely the same that struck Bettes and crew, and likely Twistex a few minutes later. It's a subvortex embedded near the center of the ~2.6 mile wide parent tornado, not a satellite on the rim or outside. The subvort was about the size of a "large, regular tornado". It's my understanding that what we'd normally call the tornado cyclone (or mesocyclone maybe) scale circulation intensified at ground level to the point that it was the effective tornado. What Josh Wurman calls the MVMC (multiple vortex mesocyclone). The more conventional tornado sized vortices within were acting like legit subvorts though. They had looping motions, erratic at times, and there were several of them embedded within the large parent circulation.

The blast of wind and debris impacts that follow in Gwyn's video are likely from an intense rear inflow jet feeding what was becoming a very visually apparent wedge. The "ghost train". I think they were correct to nose into it. Such winds can roll a high profile vehicle, and the windshield is laminated. It would likely crack, but the laminate should hold the glass in place. Whereas if the side or rear windows go, then you've got flying glass, which is what happened with Dan Robinson on the same part of the storm a few minutes later, and with Adam Lucio on the Wayne, NE EF4 a few months later. They both lost their back window. Chasers might dismiss this as RFD, but these winds are of tornadic intensity, directly feeding into the core vortex, and often included as part of the tornado track when the NWS conducts a damage survey. For all practical purposes, this is part of the tornado. And Gwyn was likely inside of the tornado itself, experiencing winds of tornadic intensity within a circulation, from about the time he turned south on 81 to until that blast of debris let up.

Gwyn's position at the time is shown here plotted with with MPAR velocity. You can see he's on the edge of some super intense inbound velocities: the jet feeding that tornado. To the south there is a huge swath of straight line RFD too, and if you look closely there's a small satellite that goes by to their south, embedded within the straight-line RFD. Pretty crazy. This video is a harrowing example of what we've been trying to stress to chasers about not racing south across the path of the RFD region on giant HPs.

 

[James Wilson]

He says the tornado is going south and he was right when he turned on 81 but this video shows the moments it started it's turn back to the NE again. As it was widening and becoming a wedge you see a skinny visual satellite but there is a larger area of circulation above them. I feel this is the moments it started to become it's widest. The debris coming at them I think is actually a spin up from the widening area of circulation. This is definitely a very dangerous situation and luckily he made the correct call to back up on 81 as it did what he was going to do. These lessons I used later in the year with the start of EF4 Wayne. What a great video to learn from.

 

[JamesCaruso]

The vortex crossing 81 is almost surely the same that struck Bettes and crew, and likely Twistex a few minutes later. It's a subvortex embedded near the center of the ~2.6 mile wide parent tornado, not a satellite on the rim or outside....

... Gwyn was likely inside of the tornado itself, experiencing winds of tornadic intensity within a circulation, from about the time he turned south on 81 to until that blast of debris let up.

Thanks for the additional analysis and clarification Skip. As I was reading the first excerpt above, I was thinking to myself, "if the subvortex was NOT on the rim and it was near the center, then doesn't that mean Gwyn was actually inside of the larger tornado?" And sure enough, that's exactly what you said later in your post.

What an incredible situation.