Meteorological Breakdown: Deadly Tornadoes Ravage Tennessee - December 9, 2023 

My sister (who lives in Clarksville TN) had a close call... a pizza place a minute away from her house was completely destroyed

Trey, this was phenomenal! I always learn so much from your analyses. I’ve been making my own forecasts every day, either for my mundane local weather or for severe weather elsewhere, and I made a forecast for this event. It was so interesting hearing you expand on things that I didn’t know to pay attention to (location of the trough’s exit region), and things that I noticed but ignored (broad temperature gradient of cold front). My forecast, which centered on Memphis, ended up being right for the wrong reasons, but I’m always learning more. Thanks for your hard work on this channel!

The past few weeks really turned out to be a tale of two events, with many of the problems of the first event underperforming being some of the reasons why the second event overperformed. The fact that dry air aloft is so finicky that sometimes it can completely suppress warm sector development while other times it can cap ongoing moderate synoptic scale forcing to allow semi-discrete supercells to live on is a testament to how difficult meteorological forecasting is. I remember checking the SPC website early afternoon that day just to see how things were going and was shocked to see a sudden upgrade to enhanced with a 10% hatched risk. Digging more into it and looking at ongoing tornadoes inside a broken line of spinning supercells really had me scratching my head. I watched the forecast video you did and obviously the wind profile was always going to be there, but for the environment to get so much warmer and more destabilized than expected is crazy. Seriously a forecasted 3CAPE of 40-50 turning into 130-150 is such a massive difference that obviously the SPC would have put out the Enhanced risk earlier if that had been forecasted. It's proof that especially in the off-season, if there's any risk, you've gotta keep your eyes and ears open. Heck look at all those tornadoes in the marginal risk area, too. It was a crazy event, and even crazier that it happened almost exactly 2 years to the day of the infamous December 2021 outbreak. Thanks for the great breakdown, Trey. I was really curious what allowed this event to overperform, and you really broke it down well. One little interesting thing I noticed when you were showing the cold front + shear vector lineup is how much more north-south the cold front was over the northern part of the risk area than was forecasted. The shear vectors weren't all that different than the models, maybe a bit higher of an angle, but the northern quarter of the cold front leading up into the surface low was much less angled than the NAM was forecasting. I think that may have also contributed a bit as the orientation of the cold front allowed the shear vectors to have that higher angle than expected. So much could be learned from this event, but at the same time, is proof that we have to keep working on making computer models better. The massive difference in low-level instability based on surface temperatures and dry air infiltration between the models and reality played such a massive role, and we can only hope things continue to improve over time. Thanks again, Trey!

Another great analysis, observed data from the airport compared to forecast showed huge difference. Condolences to everyone affected.

Thanks for making this as always Trey! Nothing better than getting surprise events broke down so in depthly like you do! Always learn a TON here. Thanks again 🙏🏽

Caught me off guard too. Because I was driving down I-65 south about 30 min before they hit. But this is sometimes how these wintertime systems can go. Hope all is well with ya Trey, and have a great Christmas!

I was stationed at Fort Campbell and lived in Clarksville for six years. I’ve traveled many of these roads I know the area well it is very surreal to me that this area was affected by a moderate, if I can say, so, tornado. It really brings home how capable mother nature can be at dramatically altering lives

Dang I remember monitoring those storms and I was surprised that a enhanced risk could do that much damage, especially because it was a slight risk the previous day.

Amazing and interesting break down as always. Every video you make is so interesting to me, and I hope you continue this content, because many of your fans absolutely love you 🎉

Ive usually got a pretty good sense of tornado weather,and i remember thinking that a tornado had probably popped up,and dismissing it cause I hadnt seen or heard any real warnings. Was mildly surprised to hear about these.great data break down

I was really looking forward to this. Excellent analysis, as always. Thanks!

Thanks! Had no idea of the complexity in tornado genesis nor if the tools available to detect and report on it.

Great video as always Trey!

Thanks for doing these. Seeing model data and forecasts before and then never seeing what was different which caused the delta in ground reality from expected is always frustrating.

Hey! I lived less than a mile from that Clarksville tornado, that was a fun day. I was working a couple miles south of the path and it took me two hours to get home due to the damage. That night I went driving around and documenting damage and over that day I drew out a path of damage on my own and got really close to the NWS path.

per usual Trey, i really appreciate your meteorological knowledge to help me learn. i also appreciate you taking the time to do these vids and break it down.

Absolutely brilliant analysis. Cheers Trey.

Excellent breakdown as always. Brandon copic got a good view of one of the cells lowering in benton county. The nashville cell was rotating as it came over my house before it crossed the tn river.

An excellent overview, Trey.

One thing I notice is that this outbreak would've highly benefited from a 5% hatched area. If I'm not mistaken, I think they used a 5% hatched area in the past once or twice. It would've more accurately displayed the chance for strong tornadoes in the unlikely (but possible) event conditions materialized. It would be an effective way to keep people more informed at a glance. Plus it'd only combine the already existing 5% area and the hatched area, so I feel like it'd be simpler to add than if they were to add an entirely new probability category (like a 20% tornado probability area for example). Of course, they did upgrade the risk later on, but having a 5% hatched area meant they could've displayed that information sooner and to a much wider audience. The audience namely being the weather news agencies who use the SPC's outlooks to inform the public, and the people who look at the SPC's risk maps without reading their forecast discussion. Hopefully the SPC opens up to 5% hatched areas in the future. Also if you end up reading this Trey, I'm interested in what you think about 5% hatched areas. Would you be opposed to them? Maybe there is an obvious reason why the SPC doesn't use them that I'm missing.

Excellent video as always. Also love the addition of circles/arrows, they make the video much easier to follow.

I have been looking forward to this breakdown. Ty so much. Words can not express how much I enjoy your breakdowns. Each one just teaches me more and more.

Stellar job Trey! I really hope you channel takes off big time because it is one of the best weather-related out there, no doubt in my mind🎉

Amazing video Trey. Always great to hear your insight into things, and thanks for coming onto me and Carly’s fundraiser with this event!

Great analysis Trey! Thank you so much :)

Those ACARS soundings are sweet! I didn’t realize airplanes provided that kind of data. Really good idea.

Great synoptic and storm-scale analysis of this fascinating severe weather event as usual, Trey!

aw man fantastic as always, loved that you brought up the bombing tornadoes discussion LOL. never quit!!!

Great video man. Thanks for the work you put into these to help us all learn.

Was at a funeral in west central TN the day before. Stayed in a hotel overnight and left early morning. My mom wanted to wait out the storm but I had been following the forecasts and knew it was supposed to last all day. So glad we left when we did.

Great info, Trey! It's always interesting to hear your breakdown of events, especially when you get specific, such as "check stubs" falling out of the sky🤣. Well done as always, friend.

Been waiting for this video

These videos are always great!

Incredible. Thank you for this video.

AYEEEEE you used my photos, big W. great vid explaining all this too!

Ooo I’m gonna save this to get hyped for my workout tomorrow. Thanks Trey!

It was a crazy day! I know some people that were very close to where the tornado went through Madison and the church they go to is three streets down from the Madison path. They only lost power but they are okay. As always, I appreciate the time and effort you put into your videos, and I learn a lot through them. Keep up the great work!

Another awesome video breakdown, Trey. I had never heard of those ACARS soundings before; glad they kept planes taking off and landing so close to a tornado so we could get that sweet, sweet data. Don't you have a Patreon in the works? If you don't, you should.

I used to live in Kentucky and it reminds me of Mayfield Tornadoes of 2021 seems like everytime around December especially in the South we get Sketchy weather instead of Snow ❄️🌨️

I live right on the Cheatham/Davidson County line where the Cumberland River crosses so when watching a radar, I can accurately pinpoint where the worst part of a storm is always heading. Being able to see the debris that was sucking up into the atmosphere was the deciding factor for me and my wife to head underground. Within minutes my ears began to pop and a roar that sounded like a freight train came from the southwest and went right over top of us. Fortunately, we prayed and did not have any damage. My neighbors to each side of us were not so lucky. For at least 300 yards in each direction roofs were blown off, barns were relocated, and giant cedar and oak trees were down everywhere. Thank God no one was hurt. It might be possible that the tornado had started to recycle and was skipping over the ground I don't know but we were very fortunate. This storm eventually made it to Madison and Hendersonville and the rest is history. Definitely a day I will never forget.

Our house is less than a mile from significant damage in Hendersonville. We’re new here and Tornadoes in general. What was surprising is the lack of any real wind at all where we are. Still, scary as hell.

Yo there it is. Been having a crappy day so I’m sure this will take my mind off my circumstances for a bit. Thanks Trey!

19:16 lmao

Always enjoy your stuff Trey. I live in Middle TN and this definitely caught everyone off guard in my sphere, myself included. I will say this reminded me a lot of the mini-outbreak of 3/3/20 in Nashville, as both were slight risk days to start with pretty marginal parameters and then the Nashville area ended up getting gut punched. The Madison Tornado passed 1/2 mile north of my bandmate near Madison, but luckily that was so close to the OHX radar that I could see exactly where it was on Radarscope and was able to let him know he was safe, if only just. Definitely made for an interesting Saturday.

Great breakdown as always Tray. As storm chaser here in Poland 🇵🇱(we don't have as much severe weather outbreaks as USA but still active spring to early winter season) I thought I knew how weather works but your forecasts and breakdowns give me a few tons of priceless knowlege. Thank you and keep up great work💪

In the words of James Spann, "when it comes to Thunderstorms, expect the unexpected"

i used to live in Martin TN, just north of Sharon and Dresden. i have people i still consider friends there. so to see Dresden get hit two years after the tornado that hit it in Dec 2021 is heartbreaking beyond compare.

Great analysis Trey. What website could I look up those Acars soundings?

Great video as always Trey, I personally did see the chance of a long tracked storm cause I had just seen Cameron Nixon’s video on Long tracked hodos and Hodo’s that day did have that long trackiness look to them, I didn’t expect the strongest storms so North though cause the “better” instability was more SW of Nashville but the better Hodos were in the north so I guess Cameron wisdom struck again with “chase the Hodograph” Mantra.

TY for the info! I would say it's systems like this that makes meteorology so interesting. The not knowing exactly what happened and trying to puzzle it out.

I live in Clarksville. While we are on the other side of the city, we still had some crazy clouds spinning right over us. But the big one missed my sister by about 1/4 mile.

the EML and 7-8 C/km steep lapse rates definitely contributed to the baseball sized hail in Northern mississippi. Over TN and KY, low level flow and SRH were also more tornado favored than what most models were showing. This definitely caught almost everyone off gaurd.

I toured OU for atmospheric sciences back in the day, but decided not to go. Just found your page in Twitter after this outbreak and after watching this video I wish I would’ve gone. Instead I will start watching these videos and try to learn as much as I can!!!! This work is fantastic keep it up!

Nice!

Man, id pay money to get classes from you. Not even kidding. Ever thought about making a masterclass marathon? I want to know everything you know. I saw your hodograph videos, still working on your others.

I woke up to a tornado watch being issued. (that's about the only thing that can wake me up lol) I knew things would get real when i heard Reed T. would be coming to Hernando! (home city) and we got a storm that went tornado warned at 1:25PM. What i find the most interesting part is siren activations and fortunately we got them! Our TOR was only radar indicated and never dropped a tornado. (and yeah I'm just now watching this lol)

where do you get all of the historical weather data and radar?

Hey Trey, this is unrelated and I’m not trying to take away any attention from this tragic outbreak from this past weekend, but I have a video idea if you would like to do it. It’s the April 10, 2009 tornado outbreak. It produced the Murfreesboro TN ef4 which touched down a mile from where I lived at the time, which is still the closest I have ever been to a tornado.

this outbreak just proves that you should always be prepared and that ef rating doesnt matter as much as the impact they have on lives and property.

Strange...i thought I commented on this one. I agree with as you started this video....this caught many off guard...though the SPC did hint....something. I was so surprised how as the event went on just how many tornadoes became long track and destructive. It is weird how these broad 5% days seem to be some of the more impressive events lately. Though that is mainly because this was quite unknown until the afternoon when it became apparent there was a chance all hell was about to break loose. I was so surprised how well these these storms stayed discrete. The Clarksville and Nashville tornadoes were insanely impressive and the supercells that morphed them were quite vigorous and almost spring-like. This will be one of those event I think we will see someone do some even more deep dive research on this, likely at a presentation conference or something. Just seeing this phase together like that into a mostly pure trough was pretty sick. That probably and other factors did like raise the SPC concerns as while the surface was good, it was the upper level conditions that got more favorable for helping these longer track supercell and made this into a really.....bullish event in the end. Also makes sense how most of the videos that got these tornadoes were either home video or webcams....look at where these formed...these would be a mess to chase. Also those ACARS soundings is strangely new to me. I didn't even know it was possible to get those from the airplanes cause I didn't think that was public data and mostly the NWS would be able to get that. I actually tried looking it up and it's still not easy to even access that data so unless you got a subscription or something to Github or stuff, that stuff is probably gonna be damn near impossible to get until a post-event. The low sounding profiles are amazing especially that near full profile one is just.....insane. Unless you are a chaser and launching a balloon literally within 4 miles of a tornado and it gets sucked into the storm, you can't get much better than that. That hodograph is so 🤌🤌🤌. Oh and the Clarksville, double RFD on the velocities is so cool. Actually as you said, these are usually only on the higher or highest tier tornadoes to get these, but that also could be from the lack of super close proximity radar data. I mean I believe the El Reno 2013 and Moore tornadoes had them but it's so uncommon to see these unless these tornadoes are like, right near the radar sites. I do like how you mentioned the Nashville tornado getting behind the RFD but it still continued. I truly was shocked that kept going and I am....actually not to sure how that is still able to do that for so long. I wonder if because the RFD got so far ahead of the tornado that it allowed some inflow to reform and allow it to continue, even if it was slightly cooler air. Hehe also yup, we can't keep bombing tornadoes to kill them off. It's almost as stupid as someone saying, let's spray ice or stuff into a hurricane and shut them down. There's SOOOO much more larger scale stuff going on that a tornado will be like "Ha that's adorable, I mean what was that suppose to do.....I will continue on as I was".

Unfortunate situation for Clarksville, the explosion in the tornado is extremely fascinating however. Could a giant heat source be what we use to disrupt the storm to prevent impacting towns? Very interesting

Can you do a case study on the Andover F5 I was at the airforce base when it went thought, before it went completely nuts. After it left the base. It was the day before my birthday. I turn 9 the day after, I was in one of the ready rooms with my dad when it hit.

There's a concept I was never able to wrap my head around. Is there any chance you could shed some light on the Zulu Time thing? 😂

Ive been waiting for this. My aunt was hit by the one in clarksville and the area i grew up in and where my friend lives was in the path of the one just north of nashville. My aunt is ok but i dont know about my friend yet. I havent been able to contact her. This event was horrible and this is one thats very personal for me. Anyway now that ive ranted im going to watch

Splanin’ to do, that’s freaking hilarious! NTSB has entered the chat. Thanks to their reckless behavior we have unprecedented data from almost within the storm.

The tornado missed my apartment in Gallatin by 2 blocks. Hit the subdivision behind me.

Hey, have a small question. What are you guys going to start actually making physical models? Because, as a sculptor and a weather fanatic that lives in North Dallas literally literally if I could sculpt a tornado. It would be interesting to do so. Understanding your method cyclone to Jimmy 3. Yes, it was called that to jackdejectory. But the idea behind it is if you want it to actually make a tornado. You need eyes on the ground to understand exactly the way the tornado looked. And single handily sculpt a direct representatiand I don't think that's ever been done. It's just cutting off an interesting idea of a master's degree from Texas Tech. And I was with the wind department for a lot of my different. Art pieces that directly derived upon not just tornadoes, but also hurricanes. And this is kind of a thing that I deal with. And if I could teach anybody about. Destruction paths or tornado formation, even hurricane formation. Maybe as far as an artist could actually be beneficial to understanding to the public, what is actually happening?

Dang!

13 to 14 miles? That’s not abnormal at all. I’ve taken off with storms way closer. It’s actually pretty safe at that distance of 13/14 miles

This area is a hotspot this time a year almost 2 years to the day

I always thought NAM tries to downplay events anyway

Explosions dont stop them confirmed lol

Another low cape high shear event

You post in my birthda-y what…

With all your expertise, verbiage, speed breakdown at light speed seemingly (impressive though), why, why, aren't you more of a factor in meteorology??? Why only revolved around a "youtube" channel - and sure to think you'll comment back at other source qualifiers but not like you're found on the weather channel or inventively pioneering the next gen weather system analytic. Like I said, impressive though.