In-depth discussion of the tornado outbreak focused on central Oklahoma on May 24, 2011. This outbreak saw multiple strong-to-violent tornadoes wreak havoc on central Oklahoma, including a 63-mile-long EF5 that traveled from near El Reno to Piedmont to Guthrie. Weāll discuss the meteorology behind the event before using high-resolution radar data to analyze the finescale behaviors of these supercells and tornadoes, including the unique tornado dissipation and genesis processes, debris ejections, a horizontal vortex, a rare tornado merger, and more.
Thumbnail images from Jon Haverfield (top) and Heather Moser (bottom) via NWS Norman.
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Chapters:
0:00 Introduction
2:54 Meteorological discussion
12:21 Overview of Canton Lake tornadic supercell
12:52 Canton Lake supercell: transition from hailer to tornadic
14:09 Canton Lake supercell: tornado occlusion
14:27 Canton Lake supercell: why such quick dissipation?
16:22 Overview of El Reno-Piedmont tornadic supercell
18:15 El Reno-Piedmont supercell: Lookeba tornado dissipation process
22:43 El Reno-Piedmont supercell: El Reno tornadogenesis process
24:19 El Reno-Piedmont supercell: rare multiple mesocyclogenesis types
25:57 El Reno-Piedmont supercell: non-descending tornadogenesis
28:27 El Reno-Piedmont supercell: sawtooth-like features in TDS
28:57 El Reno-Piedmont supercell: debris ejections
30:05 El Reno-Piedmont supercell: weak-reflectivity band, horizontal vortex
32:25 El Reno-Piedmont supercell: storm mergers and path fluctuations
33:23 El Reno-Piedmont supercell: rare tornado merger
37:12 Overview of Chickasha and Goldsby tornadic supercells
37:56 Chickasha supercell: storm merger, intensification
38:31 Chickasha supercell: subtle surface boundary aids tornadogenesis
40:50 RUC proximity sounding analysis
44:02 Wrap-up
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Resources:
NWS Norman event page: https://www.weather.gov/oun/events-20110524
National Weather Radar Testbed phased-array radar (PAR) data: https://inside.nssl.noaa.gov/nsslnews/2011/05/par-captures-long-lived-tornado-in-may-24-2011-outbreak/
āRapid-Scan, Polarimetric, Doppler Radar Observations of Tornadogenesis and Tornado Dissipation in a Tornadic Supercell: The āEl Reno, Oklahomaā Storm of 24 May 2011ā ā Houser et al. (2015): https://journals.ametsoc.org/view/journals/mwre/143/7/mwr-d-14-00253.1.xml
āA Finescale Radar Examination of the Tornadic Debris Signature and Weak-Echo Reflectivity Band Associated with a Large, Violent Tornadoā ā Houser et al. (2016): https://journals.ametsoc.org/view/journals/mwre/144/11/mwr-d-15-0408.1.xml
āImpacts of a Storm Merger on the 24 May 2011 El Reno, Oklahoma, Tornadic Supercellā ā Tanamachi et al. (2015): https://journals.ametsoc.org/view/journals/wefo/30/3/waf-d-14-00164_1.xml
āDocumenting a Rare Tornado Merger Observed in the 24 May 2011 El RenoāPiedmont, Oklahoma, Supercellā ā French et al. (2015): https://journals.ametsoc.org/view/journals/mwre/143/8/mwr-d-14-00349.1.xml
āGenesis of the Chickasha, Oklahoma, Tornado on 24 May 2011 as Observed by CASA Radar and Oklahoma Mesonetā ā Brotzge and Luttrell (2015): http://nwafiles.nwas.org/jom/articles/2015/2015-JOM6/2015-JOM6.pdf
āPolarimetric Signatures in Supercell Thunderstormsā ā Kumjian and Ryzhkov (2008): https://journals.ametsoc.org/view/journals/apme/47/7/2007jamc1874.1.xml?tab_body=pdf
āThe Dependence of Numerically Simulated Cyclic Mesocyclogenesis upon Environmental Vertical Wind Shearā ā Adlerman and Droegemeier (2005): https://journals.ametsoc.org/view/journals/mwre/133/12/mwr3039.1.xml
Heston/Goessel, KS, tornado merger footage from March 13, 1990: https://www.youtube.com/watch?v=PslT4_HwPiM
Pecos Hankās video of El Reno wedge and horizontal vortex: https://www.youtube.com/watch?v=rM-VJA5NP1s
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Roger Edwardsās photos of the El Reno-Piedmont tornado merger and subsequent larger tornado:
https://skypix.photography/tornadoes-about-to-merge/
https://skypix.photography/piedmont-tornado-after-the-merger/
https://skypix.photography/violent-el-renopiedmont-wedge/
https://skypix.photography/ef5-wedge-with-satellite-tornado/
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Nice 1 Trey. Great analysis. Dr Lee Orph used soundings from this day, to generate his amazing computer models. Howie Bluestein was a tornado research legend too. Cheers!
This portion of the outbreak sequence is often overlooked as the Joplin tornado occurred just 2 days prior. Great work as always Trey thanks for everything you do.
Man if only this video was hours long…
Hooray, it's here!
Phenomenal work as always
Wow side note but 2:19 I didn't know there was that clustering around dfw that day?! Until recently I didn't know there was an outbreak at all that day lol
Edit: actually now i do remember it now that i look at the confirmed tornadoes. I remember now cuz there was a tornado in irving which is where my dad works and i remember being so scared
Crazy tornado day from a crazy tornado year. Thanks Trey!
What's said around 32:19 is super interesting. Of course horizontal vortices are associated with violent tornados, but I always assumed that they were a by-product of them. I assumed that there was just something about violent tornados that caused horizontal vortices. I never thought to ask if horizontal vortices can cause intensification of an ongoing tornado thus making it violent.
Really, really great video. I was living in Norman back then, going to OU. Scary day. Two days after Joplin, less then a month after the Super Outbreak; it felt like it was Oklahoma's turn. I also remember seeing a lot of "May 3rd all over again," being thrown around that morning. I went chasing, and was following the Piedmont storm for a while. Never saw the tornado, though.
But yeah, really good video.
28:50 That's nothing short of incredible that the inflow jets could be resolved on radar.
Wow i wish that we had these high res radars like this everywhere!! Sooo fascinating
you are a genius my man
I glanced quickly at the timestamps before the video began and was immediately intrigued. If you're only spending 13 minutes of 44 minutes on the meteorological breakdown portion of a case study, we're in for some super in-depth content and holy cow did we get that! Not much to talk about at the synoptic scale that you haven't talked about time and time again. Strong, negatively tilted trough, diffluence aloft, powerful low-level cyclone via lee cyclogenesis, strong warm, moist advection into the target region, ridiculously stout EML atop a deep moist layer, 3k MLCAPE and large looping hodographs, all in Oklahoma? I've heard it all before, and I know a lot of fans of the channel have, and I'm sure you're almost tired of repeating that string of terms at this point!
But then to dig into such incredibly specific mesoscale factors with probably the widest wealth of thorough high resolution radar data in any of your case studies to date is so wonderful. I honestly can't even recall how many new things I learned from this video, it was 30 minutes straight of learning new things. I absolutely adore seeing the mobile radar data as digging into these finer details is so vital for understanding individual tornadoes, and I long for the day we have a wide enough network of these things that we can use them predictively as tornadoes are ongoing to help understand the danger more precisely instead of only really being able to use them after the fact.
I can't say enough good things about how wonderful this video was, absolutely fantastic video Trey and I always get excited when I see a new case study. Can't wait for more!
Great video as usual Trey.
I'd also like to share a cool little story. I live in Belgium and today we had a tornado in my city from a low-topped supercell. I was following its wallcloud from my window as I was positioned just south of the storm and it was amazing to see the dry slot cyclically sliding into the wall cloud producing multiple funnels. The final attempt succeeded in making ground contact and the result was a brief tornado that caused significant damage, I'm guessing EF1 or EF2. I guess I want to thank you, because its because of videos like yours that I could understand what was happening even before I had confirmation that the tornado actually touched down since I couldn't see it making ground contact myself. I later got confirmation from my aunt who lives in the neighbourhood where it touched down, luckily no one got injured. Thank you for these videos, they are very educational.
2011 was different, I feel like the strongest tornado of 2023 was the norm during that spring
Trey, thanks as always for another great video. You set the standard for meteorological analysis and breakdowns. You keep making 'em, we'll keep watching 'em!
Sean Casey, Reed timmer and the twistex crew was all on this storm when it aired on storm chasers show…š
Hi Trey, I hope you don't mind me mentioning another channel for tornado enthusiasts to check out AFTER watching your video š Leigh Orf is a thunderstorm and tornadogenesis researcher and has made groundbreaking computer simulations of the the El Reno tornado. I would recommend anyone interested to check out his channel.
something i did think of yesterday would maybe some an overview of info on spc risk days, like most populated moderate/high risk, or largest mod/high risk, can do the same for least populated/smallest area
Fantastic video, Trey! Iāve been waiting for another case study to pass the time during this boring stretch of weatherš
Hopefully we get more classic southern plains set ups soon, we havenāt had a good one in a while!! Thereās something so nostalgic and pure chasing big outbreaks in the southern plains for some reason! Again, amazing video!
āConvective Chronicles just dropped a new case study I canāt go out to eat with your family anymoreāā¦works everytime everybody š
I have say with as good as you are when it comes to explaining how everything works you could put on a class that lasts all day and it would be awesome you put so much detail into these shorter videos I could only imagine how much one can learn if you put on a class.
Let's go! I was really hoping you would make a case study about this day! Thanks for the great video!
Can you go more in depth on horizontal vortices? They've always been an interest for me.
Hey Trey, another phenomenal breakdown! Could you elaborate on the process behind the formation of ārollā clouds ( 11:12 )? This region of stable air where the roll pattern forms? Iām thinking itās because of the wind shear in place with a ML present above, allowing some ārollingā condensation to form but both become vertical? Wondering if you could clear this up!
Really amazing stuff Trey!
One question i have is why might the El Reno-Peidmont tornado be classified as one continuous tornado, but the Hesston and Goessel Kansas tornadoes were classified as two seperate F5 tornadoes? As it would seem they went through similar merger scenarios.
Thanks for any input or speculation on this.
That was a robust case study! Thank you!
Whoaaaaa I just watched this video and really liked it. When I subscribed to your channel and checked to see if you have other videos I cannot believe how lucky I am to come across it. 10/10
24:11… something clicked! I was wondering about this… so basically it was like two mini areas of low pressure stacked on top of one another? If one had stayed solo, the rotation would've been too broad and not tightened up.. but having two enhanced the spin.. like the figure skater that draws her arms in closer! Is that right?
Great video as always! Would really like to see you make a video comparing typical Dixie synoptic/mesoscale setups of events that blew up (April 12 2020) to ones that underperformed (April 13 2022/March 17 2021)
Dang I think I was here at like 3 or 4k subscribers. Congrats on the channel growth!
Love your videos Trey. Learning so incredibly much from your videos.