Severe Weather Threat 5/25-5/26, 2024

[Casuarina Head]

Indeed; that's why even limited convective coverage could prove devastating in environments like tomorrow's.

No doubt. My only contention is that I think tomorrow will be similar to 6 May: overall underperformance relative to expectations, but with one lone supercell that produces a potentially violent/devastating tornado (or two). Given the absence of big outbreaks in this region for a long time, along with a number of “busts” along the way, I would need to see overwhelming indication of a major event before agreeing with a HIGH TOR-wise. Only resolution of mesoscale factors on day one can really address the uncertainty. Until then I will be quite skeptical.

Low-level shear looks to be somewhat weak before 00Z, so timing is an issue, along with the cap. However, in this case overall shear vectors relative to the dry-line look much more conducive than on 6 May, and we will be dealing with a robust surface low as well. Overall the setup definitely seems to offer more potential for widespread discrete mode than 6 May. I would like to see some indication of a weaker EML and better-timed forcing, possibly among some other things, to be really confident as to the likelihood of a HIGH verifying.

 

[jiharris0220]

Yep. Had the squall line not swallowed it up, it’s no telling how long that tornado would’ve stayed on the ground.

Had storms simply remained discrete and lasted into that night, we could’ve had multiple Barnsdall like supercells running down eastern Oklahoma.

It’s seriously eerie how easily that high risk could’ve verified had storms simply remained discrete and low level shear was a bit more veered.

 

[RandomBlue]

Seems like this year we have a lot more drastic changes in forecasts from one day to the next than we have in the past.

 

[CheeselandSkies]

Had storms simply remained discrete and lasted into that night, we could’ve had multiple Barnsdall like supercells running down eastern Oklahoma.

It’s seriously eerie how easily that high risk could’ve verified had storms simply remained discrete and low level shear was a bit more veered.

I'm perhaps being pedantic here, but generally for a supercell wind profile you want your low-level winds to be backed (counterclockwise relative to winds further up, generally out of the south or even southeast) and then veer (turn clockwise, generally to southwesterly, westerly or in the summer, even northwesterly) with increasing height.

I'm not even sure if that was actually an issue on 5/6. I think it was something more along the lines of, storms had more trouble getting off the initiating boundary than expected; and interfered with each other. The difference was subtle, but enough to prohibit more prolific tornado production.

 

[buckeye05]

Honestly, the possibility of limited storm coverage tomorrow doesn’t bring my concern down much, if at all.

Sometimes days where it’s just one of two isolated supercells that have plenty of room to “breathe” and do their thing unimpeded, are days when truly unbelievable tornadic violence can unfold. However, setups where the parameters are insane, yet the radar is too crowded for cells to reach their full potential are often less memorable.

 

[Kds86z]

Had storms simply remained discrete and lasted into that night, we could’ve had multiple Barnsdall like supercells running down eastern Oklahoma.

It’s seriously eerie how easily that high risk could’ve verified had storms simply remained discrete and low level shear was a bit more veered.

April 27 though.. was significant in Oklahoma. 2 Ef3s,1 ef4.

 

[CheeselandSkies]

The difference was subtle, but enough to prohibit more prolific tornado production.

I just now realized my added alliterative appeal.

 

[jiharris0220]

Honestly, the possibility of limited storm coverage tomorrow doesn’t bring my concern down much, if at all.

Sometimes days where it’s just one of two isolated supercells that have plenty of room to “breathe” and do their thing unimpeded, are days when truly unbelievable tornadic violence can unfold. However, setups where the parameters are insane, yet the radar is too crowded for cells to reach their full potential are often less memorable.

It isn’t bad to have expansive storm coverage, it seems like the truly long track violent tornadoes start by having dominant cells go through either a merger or get nudged by the cell behind it.

April 27, 2011 was a semi discrete mode and didn’t have the issues that May 6 had, and we know how that went.

I’m anxious for the 18z runs to see changes occur if any.

 

[jiharris0220]

Also, just to remind people about after Saturday, it isn’t out of the realm of possibility to see another moderate risk the day after.

 

[Tempestas Tonitrua]

It isn’t bad to have expansive storm coverage, it seems like the truly long track violent tornadoes start by having dominant cells go through either a merger or get nudged by the cell behind it.

April 27, 2011 was a semi discrete mode and didn’t have the issues that May 6 had, and we know how that went.

NW Alabama yes, but Smithville, Philadelphia, Cullman, and then the Cordova and Tuscaloosa OWS cells were pretty much the definition of discrete.

If I think of OWS sector, picture perfect supercell my mind goes right to the Cordova storm presentation on rader

 

[hurricaneguy]

Also, just to remind people about after Saturday, it isn’t out of the realm of possibility to see another moderate risk the day after.

Perfect timing during one of the biggest sporting events too. Not good

 

[slenker]

Also, just to remind people about after Saturday, it isn’t out of the realm of possibility to see another moderate risk the day after.

Wow. Looks like it’s being shifted more north-northeast with each new run, which is pretty scary to me. (I’m in central Ohio.)

 

[OhOkayThen]

Also, just to remind people about after Saturday, it isn’t out of the realm of possibility to see another moderate risk the day after.

I think a Moderate for Sunday is pretty much a given at this time. The strong tornado chances don't currently look as high as Saturday, but it will be a much more widespread event.

 

[Brice W]

I think a Moderate for Sunday is pretty much a given at this time. The strong tornado chances don't currently look as high as Saturday, but it will be a much more widespread event.

That’s a huge area good lord.

 

[jiharris0220]

NW Alabama yes, but Smithville, Cullman, and then the Cordova and Tuscaloosa OWS cells were pretty much the definition of discrete.

If I think of OWS sector, picture perfect supercell my mind goes right to the Cordova storm presentation on rader

Discrete yes, but even most of those cells had nudgers that aided in their development.

 

[Evan]

Discrete yes, but even most of those cells had nudgers that aided in their development.
View attachment 27674

I hope to never again see a radar image like that.

 

[OhOkayThen]

Discrete yes, but even most of those cells had a nudgers that aided in their development.
View attachment 27674

I pee myself a little bit everytime I see this scan from that day. And I didn't even live in that area. Sometimes I go back and look in awe at the SPC reports and how Northern Alabama was literally just coated in red from so many tornado reports.

 

[cincywx]

digesting the 18z hrrr, it's impressive how quick the low-level winds improve from 22z to 01z in central/east oklahoma. the hrrr has held pretty solid with its depiction of one or two lone supercells in oklahoma so that will need to be watched, as will the possibility of a delay in the arrival of the low level backing of the winds. one thing's for certain - no shortage of ingredients for anything that does develop tomorrow evening.

 

[andyhb]

No doubt. My only contention is that I think tomorrow will be similar to 6 May: overall underperformance relative to expectations, but with one lone supercell that produces a potentially violent/devastating tornado (or two). Given the absence of big outbreaks in this region for a long time, along with a number of “busts” along the way, I would need to see overwhelming indication of a major event before agreeing with a HIGH TOR-wise. Only resolution of mesoscale factors on day one can really address the uncertainty. Until then I will be quite skeptical.

Low-level shear looks to be somewhat weak before 00Z, so timing is an issue, along with the cap. However, in this case overall shear vectors relative to the dry-line look much more conducive than on 6 May, and we will be dealing with a robust surface low as well. Overall the setup definitely seems to offer more potential for widespread discrete mode than 6 May. I would like to see some indication of a weaker EML and better-timed forcing, possibly among some other things, to be really confident as to the likelihood of a HIGH verifying.

No, it isn't.

 

[KCweatherboy]

I agree, but only from an analog standpoint. The same concerns with capping are still evident in my eyes - I wouldn’t entirely write off the CAMs yet if they’re still not showing much storm coverage. I mean, were there a whole lot of people saying May 20 2019 was going to be a major cap Forecasted Convective Amplification Deficiency?

I slightly disagree here, I don't think 5/3/99 is a good analog as the type of trough is rather different the placement of the surface low is forecasted to be further south than it was that day. Also different than 5/20/19.