2024-05-19 EVENT: NE/KS/OK

[Matthew Crowther]

Very consistent model run to run and model to model guidance of a possibly significant severe event for this coming Sunday centered in KS. WSW mid-level flow, a stationary front east of a surface low in eastern CO, all the ingredients seem to be coming into place. GFS forecast soundings are impressive, like this one from near ICT at 21Z. Things could change, but right now I am planning to come back out.

 

[Dan Robinson]

That's a really solid setup there that kind of snuck up on us (well, for me at least): +30kts upper to surface flow, upper 60s dewpoints, adequate CAPE, storms firing before 00z and manageable storm motion of 30mph are all there on the Euro and GFS. Has a little hints of 5/12/2004 to it.

 

[JamesCaruso]

Appreciate the heads-up on this. Sunday is my travel day out to the Plains, so I had not been paying attention to it as a potential chase day. I hadn't done any analysis for Sunday, and as of yesterday evening nothing had grabbed my attention in SPC or any of the Plains NWS offices' AFDs.

Capping looks really strong on both GFS and Euro. The dryline is much sharper on the Euro near the OK/KS border, but the cap seems unbreakable there. The GFS shows a much more diffuse dryline. But both suggest surface low pressure in west-central KS and backed winds along the KS/NE border, where the cap is weaker. Surface convergence and perturbations in the mid-level flow would have to be the triggers to break the cap.

I made flight reservations that will give me at least a chance of making it on time. I land in Kansas City at 1pm. I also considered Wichita, but I cannot get in there until 3:30 (well, there is a way to get in earlier, but I'm not willing to leave the house at 4am for a 6:20am flight and it requires a connection ) . If the target ends up being north-central KS closer to the NE border it will turn out to be the right move, but obviously not if the target is more southern KS. Hopefully the cap holds off initiation until later in the day. I'm also pretty paranoid about rental cars; I've had too many times when I got a vehicle with the oil life down near zero, or tires with insufficient tread, or a tire that was lower pressure than the others. (This happened to me again recently in Boston for my eclipse chase). At the Kansas City airport there should be a bigger selection in case I have an issue with the vehicle they want to give me and need to swap it out.

 

[Matt Hunt]

I was initially looking at Sunday as a "warm-up" day to start off my chasecation, but it sure has come together into a solid looking day. SPC issued a 15% area through central KS & NE and mentioned "supercells capable of all severe hazards." The 12z NAM looks great, though I'm not sure why there's a donut hole of dry air where the dryline pushes NE through northern KS. No other model is showing this. At any rate, capping is not an issue per the NAM as compared to others. The Euro (06z run) shows about 1000 J/kg less CAPE into northern KS, where the NAM is showing 3000+ nearly to the NE state line. Of course all of these details will likely change over the next few days, but nonetheless it does look promising, and in easily my favorite state to chase in; Kansas!

 

[JamesCaruso]

The 12z NAM looks great, though I'm not sure why there's a donut hole of dry air where the dryline pushes NE through northern KS.

An earlier (0Z) run of the GFS had a small feature like this too… I assumed it was related to model precipitation?

 

[Andy Wehrle]

12Z GFS and NAM look pretty nuts for Sunday with intense low-level shear juxtaposed with strong instability over much of central KS, possibly extending into adjacent portions of OK/NE. @JamesCaruso, you're right, reading over ICT's AFD (which they have yet to properly update since last night) you'd have no idea the GFS and NAM show what they do for Sunday over their CWA.

I've secured Monday-Tuesday off next week so I can head out over the weekend and chase Sunday-Monday in the Plains possibly followed by Tuesday more locally.

The biggest potential fly in the ointment I see is if the shortwave ejection slows down at the 11th hour as with some of the setups earlier this season, leading to a total or at least daylight cap bust.

 

[Brett Roberts]

There are several things to like about this setup, but I'm concerned about moisture quality and LCLs being a significant limiting factor. The wave currently progressing across the S Plains today will amplify some as it translates east, and is forecast still to be over FL by Sunday. As such, the "real juice" stays largely confined to the TX Gulf Coast region well into the weekend, then attempts to surge back into the heart of the Plains during the day Sunday. With such zonal flow in place over the target area, it's easy to imagine this shallow last-minute moisture mixing a lot near the DL. This has echoes of May 6, as does the tendency I see on the ECMWF and UKMET for surface winds not to back much beyond due S in many areas along the DL. Combine this with relatively warm temperatures in the 700-850 mb layer and drought across C KS, and my expectations for long-lived, discrete, surface-based supercells with higher end tornado potential are decidedly tempered for now.

The good news is that my track record so far this year with commentary in FCST threads has been abysmal, so make sure to move those chasecation flights up to Saturday now!

 

[Mike Smith]

FWIW, the moisture should be less of a problem this weekend in the sense that (at right), there has finally been some rain in Kansas (7-day rainfall shown) with heavy rains in many parts of TX and OK the last two weeks. More is forecast in the southern Great Plains now through Saturday afternoon.

 

[Matthew Crowther]

Appreciate the heads-up on this. Sunday is my travel day out to the Plains, so I had not been paying attention to it as a potential chase day. I hadn't done any analysis for Sunday, and as of yesterday evening nothing had grabbed my attention in SPC or any of the Plains NWS offices' AFDs.

Capping looks really strong on both GFS and Euro. The dryline is much sharper on the Euro near the OK/KS border, but the cap seems unbreakable there. The GFS shows a much more diffuse dryline. But both suggest surface low pressure in west-central KS and backed winds along the KS/NE border, where the cap is weaker. Surface convergence and perturbations in the mid-level flow would have to be the triggers to break the cap.

I made flight reservations that will give me at least a chance of making it on time. I land in Kansas City at 1pm. I also considered Wichita, but I cannot get in there until 3:30 (well, there is a way to get in earlier, but I'm not willing to leave the house at 4am for a 6:20am flight and it requires a connection ) . If the target ends up being north-central KS closer to the NE border it will turn out to be the right move, but obviously not if the target is more southern KS. Hopefully the cap holds off initiation until later in the day. I'm also pretty paranoid about rental cars; I've had too many times when I got a vehicle with the oil life down near zero, or tires with insufficient tread, or a tire that was lower pressure than the others. (This happened to me again recently in Boston for my eclipse chase). At the Kansas City airport there should be a bigger selection in case I have an issue with the vehicle they want to give me and need to swap it out.

There are several things to like about this setup, but I'm concerned about moisture quality and LCLs being a significant limiting factor. The wave currently progressing across the S Plains today will amplify some as it translates east, and is forecast still to be over FL by Sunday. As such, the "real juice" stays largely confined to the TX Gulf Coast region well into the weekend, then attempts to surge back into the heart of the Plains during the day Sunday. With such zonal flow in place over the target area, it's easy to imagine this shallow last-minute moisture mixing a lot near the DL. This has echoes of May 6, as does the tendency I see on the ECMWF and UKMET for surface winds not to back much beyond due S in many areas along the DL. Combine this with relatively warm temperatures in the 700-850 mb layer and drought across C KS, and my expectations for long-lived, discrete, surface-based supercells with higher end tornado potential are decidedly tempered for now.

The good news is that my track record so far this year with commentary in FCST threads has been abysmal, so make sure to move those chasecation flights up to Saturday now!

Well, I agree that "high-end long-lived tornadoes" are not super likely, but given the strong hodograph curvature forecast I would think very good structure and maybe a non-strong tornado is possible, and for me, that would do just fine.

 

[Mike Smith]

I also considered Wichita, but I cannot get in there until 3:30 (well, there is a way to get in earlier, but I'm not willing to leave the house at 4am for a 6:20am flight and it requires a connection ) .


Hi Matthew, I don't know if you have a refundable ticket but (since your tag says you are in ATL), you can get to ICT pretty conveniently on Sunday. While there are several non-stops, the one at 9:16a, which arrives ICT at 10:32, would seem to work fine.

 

[Matthew Crowther]

I also considered Wichita, but I cannot get in there until 3:30 (well, there is a way to get in earlier, but I'm not willing to leave the house at 4am for a 6:20am flight and it requires a connection ) .


Hi Matthew, I don't know if you have a refundable ticket but (since your tag says you are in ATL), you can get to ICT pretty conveniently on Sunday. While there are several non-stops, the one at 9:16a, which arrives ICT at 10:32, would seem to work fine.

I am not flying, it is Jim Caruso. I am driving, leaving Saturday.

 

[JamesCaruso]

I’m not trying to put too fine a point on my analysis at this range, but I think we may be overestimating the potential here, as a result of seeing some necessary ingredients finally return to prime chase territory for the first time in what will be two weeks by Sunday. Among the NAM, GFS and Euro, only the NAM shows any sharpness and decent convergence along the dryline - and that’s toward the KS/OK border where the cap is not likely to break. Midlevel temps are quite warm so I see capping as a definite issue, without much dryline convergence to overcome it. The midlevel wave is compact and there is a relatively small area of stronger (i.e. 50 kt) 500mb flow. While hodographs generally have favorable shapes, midlevel shear is weak in many spots; in areas where it is stronger, the thermodynamic profile is less favorable, with strong capping and minimal 3CAPE. Question is whether instability and shear will overlap. I’m sure they will in spots, but there is still enough variability among these three models; it will be interesting to see what the CAMs say as we get closer. SPC does not seem too enthusiastic, nor does the ICT AFD.

It should be a good chase day no doubt, but let’s just say it’s not the type of setup where I’m all pissed off that I can’t fly in on Saturday instead and I’m not about to force my son to bail on his Saturday night valet parking shift For me landing in KC at 1pm, probably hitting the road no earlier than 2pm by the time we get our luggage and rental, my target is going to be more about the best one i can get to, rather than the best one overall. But I like the idea of being towards the NEB border on the edge of the stronger cap, which will also be easier to reach from KC. Maybe it will turn out to be more of a nowcasting situation by the time I get on the road, although I suspect the cap will hold things off.

 

[Matt Hunt]

FWIW, the 12z NAMNST is breaking out convection all the way down into OK. Something to watch day of will be any outflow boundary from overnight convection. I see this as a day that could go either way. The lack of adequate moisture, and possibility of a strong cap could lead to weak storms or even no storms, but depending on the mesoscale details, we could also get a nice tornado or two.

I'll likely be driving to Denver tomorrow, possibly continuing on to Limon, which should put me in a good position to get to any possible target on Sunday morning.

 

[Andy Wehrle]

Unlike some prior setups this year (notably April 15th), I'm not seeing moisture depth being an issue across the board on forecast soundings; at least not where the moisture tongue hits the WF and curls back toward the triple point, which is the spot that has my interest for this day and wherever that sets up (north-central KS seems most likely, and has for a while IMO) is my target.

First sniff of the NAMNST is rather encouraging, as it seems the likely outcome is a happy medium somewhere between what it shows, and a cap bust.

Just the EHI plots on the GFS and NAM and their consistency with them remind me of May 26th, 2021. I had been focused on the target I described above, which was plotted over southwest Nebraska, but en route I caved and went down the dryline into west-central KS, and anyone who chased that day knows how that turned out.

 

[Brett Nickeson]

Just the EHI plots on the GFS and NAM and their consistency with them remind me of May 26th, 2021. I had been focused on the target I described above, which was plotted over southwest Nebraska, but en route I caved and went down the dryline into west-central KS, and anyone who chased that day knows how that turned out.

Ha, that was the exact chase day that came to mind when looking at this setup. Bit different WF orientation but similar look. Maybe it's just PTSD though...