Meteorological Breakdown: Similar Setups, Different Outbreaks - March 31 and April 4, 2023

In-depth discussion of the two bimodal severe weather outbreaks that occurred on March 31 and April 4, 2023. We'll discuss the meteorology behind both outbreaks, notable storms from each, and why the outcomes of each outbreak were so different despite similar forecasts and background patterns.

Contents
0:00 Introduction
3:27 Meteorological overview - northern mode - March 31
38:53 Keota, IA, tornadic supercell breakdown - March 31
48:25 Sullivan, IN, tornado breakdown - March 31
52:36 Meteorological overview - southern mode - March 31
01:12:29 Little Rock, AR, tornado breakdown - March 31
01:16:46 Wynne, AR/Covington, TN, tornadic supercell breakdown - March 31
01:23:39 Meteorological overview - April 4
01:50:50 Pleasantville, IA, tornado breakdown - April 4
01:56:16 Lewistown, IL, tornadic supercell breakdown - April 4
02:02:17 Discussion on tornado deviance - April 4
02:04:14 Discussion of capping issues in southern mode - April 4
02:06:21 Conclusion

[SvrWxArchive]

2 hours?!? How have we been BLESSED with such amazing content today!

[bigtodd]

Seeing the March 31 outbreak being listed right next to 4/27/2011 and 4/3/1974 in terms of tornado count is astounding

[WeatherWatcher]

Incredibly detailed and high quality video, it takes a lot of work to sit down and go in depth on 2 severe weather outbreaks for 2 whole hours… great job!

[evanfryberger]

Finally! The worlds first severe weather break down movie 🍿

[vivlund]

Thanks for giving us the play-by-play on this event!

[MetallicAAlabamA]

I know I keep saying this. But you have the best in depth analysis of any meteorological style channel. It's not under done and it's not over done with how you present your case studies. It's simple, with a seriousness that's fun to watch if you're into meteorological science. You seem to be getting more comfortable also when presenting these analysis, which is awesome. Thanks again for what you do Trey! Ok, so I've told you how I've felt about your work. But I figured out how to do that without being the same thing over and over. I just reword a few things and that seems to work 😂! Have a good one bro and take care!

[topaz]

You and June First both have given me significant insights to how this all works, and I appreciate you both so much! Keep up the amazing work man, super informative.

[MyFatherLoves]

still remember 3/31 like it was yesterday. I work in Little Rock, AR and I'm very thankful to have had the ear of my boss by that time. I strongly suggested he send us home, he did. The EF3 came within 100yrds of our work and about a mile of my home in North Little Rock. Thankfully, we were able to coordinate our interpreters across Little Rock to get them to safety and check on our large deaf/blind community just after the tornado tore through.

Ryan Hall was pivotal in helping us get our interpreters to safety.

[Austin_Dale]

I will always have a piece of the March 31 outbreak with me. I go to college in Vincennes Indiana which is 30 minutes south of Sullivan. Went to check out the EF3 damage, and on the way back to my car about half a mile from the damage path I found a piece of a door frame shoved into the ground, with 2 door hinges still attached.

[AF]

Looking forward to watching this! It'll be cool to see a breakdown of a setup I chased. Not to brag or anything, but when we chased on 3/31 in NW/Central IL we saw absolutely nothing in our 10 hours of driving, not even any hail or lightning, which is honestly really impressive considering how widespread everything was. my initial target 2 days before was near Ottumwa, and I'm still kicking myself for not committing and being more vocal, but I'm the least experienced and confident person in our group and the setup kept looking better for IL so we chose to stay East of the Mississippi river.

[Grimm_reaper]

Crazy thing is I live in the high risk area Iowa was in on march 31st, and on march 25th that area was covered in snow when we woke up that morning. (The most snow I’d ever seen on my birthday)

[dannygray-mixn]

Bloody brilliant. Great work as always. Cheers Trey.

[SSVR]

Hey made it to the end😂

Always enjoy hearing your insights!

[runt]

Man, Trey, you knocked this one out of the park. 2 hours straight of deep-dive weather details and I loved every second of it. There's a ton I could run through but I'll keep it short and sweet.

I really wonder if some stronger ridging from the high pressure streaming up from the Gulf slowed the trough down on April 4th. It really feels like it came to a crawl right before its ejection which threw so many things out of whack. From a parameter space perspective April 4th had a higher ceiling than the 31st, there was more instability and higher shear almost across the board, but that dry air aloft and slowed, weak forcing just... stopped storms from forming. I still am blown away by the dry air being seemingly lifted out of the gulf on the water vapor imagery from that morning.

March 31st definitely hits the raw number of tornadoes, but at this point we only have a single EF4 and no EF5s. I think it's a perfect example of what a gigantic warm sector with textbook forcing in a low to moderate parameter space can create. It was storm after storm after storm dropping mostly short-lived, strong-but-not-violent tornadoes over just an incredibly large area. And while we did have some small areas with incredibly large shear values, we never really saw any of the crazy MLCAPE values we saw on days like the Super Outbreak. If we had April 4th's parameters with March 31st's perfect trough ejection, we would be talking about a historic, violent outbreak. But just very interesting how many EF3s we had, wide swaths of moderate to strong damage, but very few places saw complete destruction.

Anyways, lots of stuff going on throughout the 2 hours, I could definitely go on and on, but the stalling of the trough on April 4th, and the seeming lack of really long-track violent tornadoes in an otherwise prolific, historic outbreak on the 31st were the two main interesting bits to me.

Thanks again for putting all of this together. As you RT'd, #1 record-breaking January to March tornado season so far this year, but now we've got some serious ridging taking hold and other than Friday/Saturday potentially bringing a severe outbreak with a bit of a tornado threat, the pattern seems to mostly be keeping these forming troughs at bay for the next couple weeks.

[peachxtaehyung]

Great video as always trey! I wasn't expecting 2 hours but I'm not complaining!

[BattleshipOrion]

My town (Wapakoneta, Ohio) was hit at 1:15am, on the first of April. Lost a greenhouse, screwed up the truck-stop, a couple of factories (some evidence of this is still visible of you are on the I75-Ohio 33 interchange, I think that's exit 110, 'cuz Wapak is 111) one of which has not been repaired or demolished yet, and we only had one injury. It was an EF-1, and was part of the March 31st system.

[chrismiller]

I was driving from Stl to Okc in the afternoon on the 31st and drove through/damn near the middle of 2 storms on 44 that tried to form a funnel right above me. This was right before meteorology became a big hobby and before I had any real in depth knowledge of stuff. Started my kick off for storm chasing and learning everything I could about weather interpretation.

[MightyMuffins]

Alright now this was awesome to go through. First off thanks Trey for putting this together. As someone with a fair bit of....well...2+ hour chase videos on my channel and funneling through my radar/sat/obs stuff and putting it into them 2 hours can be a little pain in the ass for rendering and waiting for stuff for youtube to load and process especially to HD.

First off the 31st system....this was just insane to watch and I remember basically watching it from start to finish and just crazy stuff on twitter. Always interesting to see when you flip quick to the 2011 event and just look at it and see it again. I mean that set up....well....that's a once in a 50 year set up. Just insane to see that huge low and insane southern jet. Now, on the Mar 31st event, I was mainly trying to get the feeds from the local stations out there in IA and IL during these events and like most cause it's interesting to hear from them that know the areas and follow along usually. The more nitty-gritty aspect of it that I think you don't get from the YT weather streamers cause you get the more "we know this area like a fine tooth comb as we cover areas daily". Just remarkable to see how discrete all the storm stayed but what was more amazing was the duration of how long it took for these to chain up to start eliminating the more high EF3+ tornado potential but still getting TONS of EF0-EF2 tornadoes in the QLCS line and just that was nuts and obviously where majority of the reports did end of up in the Northern mode. The Keota, IA tornado is just one of the more impressive tornadoes I think we have seen...honestly since the Rochelle, IL tornado. I know many will point to the Rolling Fork tornado or even the Mayfield tornado and others we have seen recently....but I think there's a recency bias people have cause those were such prolific events and so destructive but the video is at night so it's hard to make out the photogenic nature of these powerful tornadoes. The Keota tornado is just on that Rochelle tornado level cause of how visible and the insane motion of the tornado. Like the structure of it and the fact we got twin tornadoes out of it puts it far above some of the tornadoes we have seen the last 7 years in terms of a meteorology aspect in my opinion and the fact it mostly stayed rural was good. Devin Pitts photo is basically....well that as a chaser, that's gonna be damn near impossible to top and that's a "career defining though am surprised I missed seeing Andy Wehrle's video of that tornado but damn that's so impressive. So many chasers were on that tornado....though some played with fire with that tornado and nearly got in some really poor situations. You don't mess with a EF4 beast like that.

I do agree with the Hannibal, MO storm and I think if it just remain more on it's own and didn't have the crap to the SSW of it it would have been a hefty tornado producer like the Keota storm but just enough interference capped that from going full tilt nuts. Love the proximity soundings you were able to gather for this cause shows all the minute differences in all the storms that were popping off. Just so much low level energy for these storms to work like that Sullivan, IN tornado. That hodograph is just stupidly insane and the parameters on that were nuts on the environmental soundings. Oh and yes there's virtually no video of the tornado and I remember watching 2 network channels as the tornado was in progress and while they did have traffic camera and tower cameras around the area of Sullivan, it was not viewable and some of the cameras couldn't face the SW direction of the storm and it was pretty much a semi-rainwrapped tornado I think. To my knowledge I think a couple chasers were trying to get on that storm but could only follow it from the West as they were diving out of the IA/IL storms and never could make it to the storm but could make it out visually but no video as most were MILES away from it and likely only saw it on the horizon being it so dark out. Basically, timing of that storm and just when it came in lead to it being a really bad storm for the town.

Now the Southern Mode and the 31st. Where you went to chase, and I approved of your choice to do that...mostly cause it would also keep your chase $$$ cost down too. Paid off too as you got the Little Rock tornado. Loaded gun soundings everywhere. Trey, I think I said on the morning when it went high and before hand I would be more concerned on that Southern mode due to how long duration this event had the potential to be and the fact this would be a more nocturnal event was what I was more worried about. I mean that dry line and warm sector was just gonna sit and cook for the entire day and it would take LONG before the cold front would catch up to the dry line and just rip on through. It was pretty much gonna be max tornado potential well into the overnight and that's kind of what happened and I remember having to get on my overnight shift from work to see it all. The pre-frontal trough in the Southern mode there was just one of the more pronounced I have seen since I think one of the January set ups though this was just more primed for how far ahead of the dry line/cold front and into the warm sector this had the chance to cook in. I mean the moist layer around the sector extending to 700mb is so impressive by 18z. I think the more impressive thing is on the Little Rock tornado like the other ones you can see the debris on the CC get sucked up into the updraft and see it get ejected way out ahead of the storm out of the anvil. The Wynne tornado kind of a wild tornado and it was just a big mass. I think that's what caught kind of chasers a bit off guard a bit chasing and following it and especially just the common person in town is that it it was just looks like a big dark blob. It's not simple to make out a the structure of the tornado itself but people like Pecos and Zach were probably in the only spots to truly see the tornado clear enough. Oh and you did mention the lack of deviant motion, yeah that was something that I almost had an argument with WX people on twitter that should know better. People seem to just be stupid when mentioning it saying "this tornado had a lot of deviant clearly like the Little Rock tornado and Covington/Wynne tornadoes were mostly straight pathed. I kept telling people you can have some wobble in a tornado path but they were still mostly straight pathed but people still said otherwise which was frustrating. The El Reno tornado is like....that's what a deviant tornado truly is. Hence why, the Covington to Wynne tornadoes were pretty much in the same "straight path" with not really a northern occlusion as you said too.

Onto the 4th, yeah this was similar to the 31st in terms of a objective view but not the same by far as it wasn't as....mature of a system. The diffulence regions were a lot more tighter and not just a pronounce huge region from WI to AR. Also so apparent you can see the lack of a major jet streak too on the 4th too around the the main issue still with this system was the EML and some of the strong mixing we got too. So pronounced across many areas and while the trough could have been like the 31st, it was far from it. It was a really weird and complex system on the Northern mode cause models were so confused on how to handle the system even hours before the event and that warm front was so tricky to forecast how storms would play out along it and in the warm sector of it. In a way the HRRR did do a fairly good job hinting how strong the mixing was gonna be for this event and that did help cap the crap out of the region in terms of the tornado potential. The warm front basically was the true trigger for the tornado we did end of seeing and some of those tornado were actually pretty strong but yeah you needed to be along the warm front and the extra little forcing you needed to overcome the strong EML and mixing too. Honestly speaking I was surprised the Southern mode didn't produce as much as it did especially tornadoes. I thought as the trough moved East I expected some stuff to fire off with some with some robustness but man....nothing cooked up and honestly was quite surprised. I fully expected the EML and mixing in the Southern mode to be able to have fought that off in the better part of the warm sector and less heating like what was happening in the Northern mode but nope. Hell, even was expecting the LLJ to help too but nope....nothing really cooked....well except the Glen Allen tornado and I was seeing that live on my overnight shift.

I will say the drill bit tornado around Pleasantville, IA was just crazy. Some of the videos really do show it as almost a true 'Twister' tornado but I loved the ropey wonky structure it had. Such a long tube. The Illinois storm, even though it didn't produce a long track tornado and took a bit to condense into a big storm...it was a huge supercell when it was tornado producing and Peoria, the 2nd time in about a month that city got spared from a tornado.

Overall, just a wild 2 events. Also on these events, chasers got caught on these tornadoes and people really need to be self aware that you don't need to get stupid ass close to these tornadoes....I personally never get it. Makes me yell into my meteorology degree. Maybe it's cause I chase in Albany and I am used to playing it safe so much filming and the fact we don't get tornadoes much in NY that I have learned over my lifetime since having a car, I don't need to get close to get wonderful structure as we get 90% cold fronts and shelf clouds. At this point, it's likely impossible to stop people from getting close and into bad spots but at least I know from how I chase I know and feel like I am being smart with my decisions to continue chasing for another day.

[Larry_Harvilla]

So I was on a (truck) load of frozen garlic bread, which I had picked up on March 29 a few miles outside of Vineland, NJ. Following Interstate 76 across Pennsylvania into Ohio, and then Interstate 80 all the way to Sacramento, I had made it as far as eastern Iowa by the late afternoon hours of March 31, just in time for the SPC high-risk area to light up with all manner of nasty shit. About 25 miles past the Quad Cities, as I was approaching the Wilton rest area, I actually spotted a visibly rotating mesocyclone, and hastily made the decision to stop at the rest area and let the mesocyclone cross I-80 before proceeding. I sat out 15-20 minutes of Noah's Ark-level rain, allowed the sun to pop back out, and then took off again.

It turned out I made a good observation for somebody who knows a little bit more about weather than most, but not nearly as much as chasers and other people with expertise in it; and it turned out I made a good decision to stop. Maybe two miles west of the main Wilton rest area, there is a truck-parking-only rest area, and off the right side of the off-ramp, another truck driver hadn't been so fortunate: his truck was laying on its right side. I did see him walking around his truck, apparently uninjured but clearly in disbelief that he had been blown over. I wasn't close enough to know whether the mesocyclone had dropped a tornado to the ground, but I do have an idea what kind of wind is required to blow a truck over, and seeing a blown-over truck tells me high-end EF0 to low-end EF1.

I wasn't done with severe weather on that load. Reaching Laramie, WY by the end of April 1, I was forced to shut down there because the Wyoming Highway Patrol had closed I-80 west of Laramie to trucks due to high winds. Then, by early evening of April 2, I had to stop at Rock Springs, WY as a blizzard moved in; I was there until April 5 by the time WHP re-opened I-80 from that one. I still couldn't get anywhere, though, because some lady flipped her pickup truck and camper in tow on its side near the I-80/I-84 interchange in Utah and had it blocked for several hours. It was the morning of April 8 before I finally reached Tracy, CA.

[jamessimon]

Insanely good analysis once again! You are really getting people interested in weather sciences. This type of content is what makes this platform so powerful. I understand the concept of a trough, but can anyone explain the concept of trough "ejection" and what that means in general. I cant find much online on the subject.