April 11-13, 2022 | Tornado Outbreak

[Iceresistance]

The high Parameters have increased further south on 4/12, this is the 6z GFS sounding over OKC

[ElectricStorm]

As expected, a slight west shift for Tuesdays slight risk. If we get a bit more model agreement we'll probably see some 30% areas pretty soon. 

I think the GFS is too progressive for Wed and so far the SPC agrees. I wouldn't be surprised to see some west shifts there as well but that one is more uncertain for now. 

[Iceresistance]

6 minutes ago, OKwx_2001 said:

As expected, a slight west shift for Tuesdays slight risk. If we get a bit more model agreement we'll probably see some 30% areas pretty soon. 

I think the GFS is too progressive for Wed and so far the SPC agrees. I wouldn't be surprised to see some west shifts there as well but that one is more uncertain for now. 

Higher risks may be warranted if there is stronger model consistency

Spoiler

...DISCUSSION... A multi-day severe weather event appears likely across parts of the central CONUS from Day 4/Monday through Day 6/Wednesday. Large hail, damaging winds, and tornadoes all appear possible each day.

...Day 4/Monday: Southern Plains into the Ozarks... An upper trough should amplify over the western CONUS on Day 4/Monday. There is still some uncertainty regarding the amplitude and placement of a leading shortwave trough over the Upper Midwest vicinity Monday morning. Some convection aided by strong low-level warm advection may also be ongoing Monday morning over parts of MO. This activity could impact the northward extent of low-level moisture return across the southern Plains and Ozarks through the day. Even with these lingering uncertainties, at least isolated severe thunderstorms should develop by Monday afternoon along and east of a surface dryline which should extend across central OK/TX, as modest ascent preceding the upper trough overspreads the warm sector. Moderate to strong instability and steep mid-level lapse rates combined with adequate deep-layer shear suggest a threat for large hail with any supercells that can develop. Damaging winds may also occur. Given the gradually increasing low-level moisture and strengthening low-level jet Monday evening, some threat for tornadoes should also exist as convection spreads eastward.

...Day 5/Tuesday: Southern/Central Plains into the Mid Mississippi Valley... The large-scale upper trough centered over the western states on Day 5/Tuesday is forecast to amplify as it ejects eastward across the Rockies and adjacent High Plains through Tuesday night. There are still some large differences between various deterministic models regarding the placement and amplitude of this ejecting upper trough. The slower, more amplified solution suggested by the ECMWF and its ensemble mean would suggest the primary surface lee cyclone may focus across the central High Plains through Tuesday evening, with a dryline extending southward across the southern Plains. The faster and more northern placement of the upper trough by the GFS would argue for a more northward warm sector development and farther east surface low placement across the central Plains into mid MO Valley. Regardless of these differences, severe thunderstorms will likely develop by Tuesday afternoon along much of the length of the dryline across the southern/central Plains. The presence of steep lapse rates aloft, diurnal heating of a moist low-level airmass, and gradually strengthening deep-layer shear should support a mix of multicells and supercells capable of producing large hail, damaging winds, and tornadoes through Tuesday evening.

...Day 6/Wednesday: Southern/Central Plains into the Lower/Mid Mississippi Valley... Large differences exist in model guidance by Day 6/Wednesday with the placement of the upper trough/low ejecting across the Plains. The slower, more southern solution offered by the ECMWF and its ensemble mean suggest a substantial severe threat exists along/east of the dryline from KS/OK/TX extending eastward into parts of the lower/mid MS Valley. Strong deep-layer shear combined with moderate to strong instability would support supercells with all severe hazards possible, including tornadoes. The faster, more northern solution indicated by the GFS would shift the greatest severe threat a bit farther east across the lower/mid MS Valley through the day. The solution offered by the ECMWF has been favored with this outlook, as it has had run-to-run consistency and strong ensemble support. Have therefore expanded the 15% severe area to include more of the central Plains and lower/mid MS Valley. If model agreement increases, then greater severe probabilities will likely need to be introduced. An organized severe threat, including the potential for tornadoes, may continue Wednesday evening/night across the lower MS Valley and Mid-South regions as a southerly low-level jet strengthens, enhancing low-level shear in the presence of sufficient boundary-layer instability to support surface-based thunderstorms.

Edited April 8, 2022 by Iceresistance

[ClicheVortex2014]

Worth noting that this is the outlook for the day we've been mostly talking about... it's not the one where they mention higher probabilities. (I had to double check myself.) They mention multicells which suggests to me that they're expecting either messy storm mode or borderline shear for supercells... which suggests to me that they're leaning more toward Euro

   ...Day 5/Tuesday: Southern/Central Plains into the Mid Mississippi
   Valley...
   The large-scale upper trough centered over the western states on Day
   5/Tuesday is forecast to amplify as it ejects eastward across the
   Rockies and adjacent High Plains through Tuesday night. There are
   still some large differences between various deterministic models
   regarding the placement and amplitude of this ejecting upper trough.
   The slower, more amplified solution suggested by the ECMWF and its
   ensemble mean would suggest the primary surface lee cyclone may
   focus across the central High Plains through Tuesday evening, with a
   dryline extending southward across the southern Plains. The faster
   and more northern placement of the upper trough by the GFS would
   argue for a more northward warm sector development and farther east
   surface low placement across the central Plains into mid MO Valley.
   Regardless of these differences, severe thunderstorms will likely
   develop by Tuesday afternoon along much of the length of the dryline
   across the southern/central Plains. The presence of steep lapse
   rates aloft, diurnal heating of a moist low-level airmass, and
   gradually strengthening deep-layer shear should support a mix of
   multicells and supercells capable of producing large hail, damaging
   winds, and tornadoes through Tuesday evening.

 

Edited April 8, 2022 by ClicheVortex2014

[Iceresistance]

@Ingyball12z GEFS has a mean Supercell Composite of a 10 in Southern & Central Kansas

[StormfanaticInd]

I haven't seen a spring with this much potential since 2011 to be honest. One outbreak after another 😳

[StormfanaticInd]

 

Plenty of instability for tornado alley.

Edited April 8, 2022 by StormfanaticInd

[ElectricStorm]

CIPS analogues for Tues are starting to get wild. Lots of big days in here

https://www.eas.slu.edu/CIPS/ANALOG/DFHR.php?reg=GP&fhr=F108&rundt=2022040812&map=thbSVR

Still a lot of uncertainties but my concern for Tues is slowly starting to rise. 

Edited April 8, 2022 by OKwx_2001

[Iceresistance]

41 minutes ago, OKwx_2001 said:

CIPS analogues for Tues are starting to get wild. Lots of big days in here

https://www.eas.slu.edu/CIPS/ANALOG/DFHR.php?reg=GP&fhr=F108&rundt=2022040812&map=thbSVR

Still a lot of uncertainties but my concern for Tues is slowly starting to rise. 

I've already put Tuesday as another day to watch, I believe that Wednesday is now dependent for the outcome at the northern end on Tuesday's event.

[ClicheVortex2014]

1 hour ago, OKwx_2001 said:

CIPS analogues for Tues are starting to get wild. Lots of big days in here

https://www.eas.slu.edu/CIPS/ANALOG/DFHR.php?reg=GP&fhr=F108&rundt=2022040812&map=thbSVR

Still a lot of uncertainties but my concern for Tues is slowly starting to rise. 

Euro's starting to show a little more for Tuesday though effective shear is really borderline. Probably good for some cyclical HP supercells. 

 

Some nasty analogs for Wednesday for the mid-MS/lower-OH valley but I'm not willing to really even touch that day until Tuesday is figured out. 

Chances are, whatever happens Tuesday will eventually grow into a MCS of some strength. That'll throw a wrench into Wednesday. The southern states are probably not as likely to be impacted because the MCS should have some northerly motion with it. Regardless, that's part of the reason why I'm surprised SPC mentioned a potential enhanced risk for Wednesday and not Tuesday. I get it, shear will be more favorable and therefore, given instability, the severe threat will be higher. But with overnight convection, is any amount of instability a given at this point? I don't think so 

Edited April 8, 2022 by ClicheVortex2014

[ClicheVortex2014]

Just got a round of small hail or graupel. Got a decent amount of sun today so I'm not too surprised.

[Iceresistance]

Found this sounding on the 18z GFS over town, going to get the Storm Shelter ready very soon.
 

[ElectricStorm]

18z GFS has a slight west shift for the southern part of the dryline for Wed. The rest of the days look similar. Looks like Monday is trending more south so we might see the slight risk trimmed. 

[ClicheVortex2014]

Gotta hand it to GFS for being extremely consistent in the past day and a half. Could be consistently wrong but... hey. Still impressive to be this consistent

Edited April 8, 2022 by ClicheVortex2014

[ClicheVortex2014]

Gonna be mass storm chaser convergence on E OK/SW MO/NW AR

 

Edited April 8, 2022 by ClicheVortex2014

[1816]

4 minutes ago, ClicheVortex2014 said:

Gotta hand it to GFS for being extremely consistent in the past day and a half. Could be consistently wrong but... hey. Still impressive to be this consistent

After the winter we just observed I think it's safe to say the gfs isn't the laughingstock it once was. Based on the observations we saw it may adjust at the last minute but when it stays locked on it has a good chance of being in the ballpark. I trust it a lot more than I used to. 

[Iceresistance]

1 hour ago, ClicheVortex2014 said:

Gonna be mass storm chaser convergence on E OK/SW MO/NW AR

 

It's been a while since I've seen something like this in Tornado Alley

[Ingyball]

Was gone this past week for the New Hire Course in KC. Only just now catching back up with everything. Tuesday is definitely interesting, but I need to look into it a bit more. Seems more like a May setup on the GFS though.

[Iceresistance]

7 hours ago, OKwx_2001 said:

CIPS analogues for Tues are starting to get wild. Lots of big days in here

https://www.eas.slu.edu/CIPS/ANALOG/DFHR.php?reg=GP&fhr=F108&rundt=2022040812&map=thbSVR

Still a lot of uncertainties but my concern for Tues is slowly starting to rise. 

Really does look like a a big event for Oklahoma as well

[Iceresistance]

Welp, I did not noticed this dangerous sounding over OKC on the 18z GFS until now, it appears that the sounding is even more favorable for Powerful Supercells than a good portion of Kansas!

I don't know how the sounding is not screaming "PDS TORNADO" on the Hazard type, maybe it's just shy of it, but still, it appears that Tuesday is looking even more dangerous than Wednesday for Oklahoma.

Strongly considering getting the Storm Shelter ready for this.

Edited April 9, 2022 by Iceresistance

[ElectricStorm]

10 minutes ago, Iceresistance said:

Really does look like a a big event for Oklahoma as well

I think the biggest question is if the cap will be too strong or not. It definitely could be, and as we've seen pretty recently, a strong cap can ruin even the biggest of setups. I think we will be looking at a few scattered supercells with tornado potential, but I'm hesitant to go with anything more than that for now.

Edited April 9, 2022 by OKwx_2001

[Iceresistance]

5 minutes ago, OKwx_2001 said:

I think the biggest question is if the cap will be too strong or not. It definitely could be, and as we've seen pretty recently, a strong cap can ruin even the biggest of setups. I think we will be looking at a few scattered supercells with tornado potential, but I'm hesitant to go with anything more than that for now.

It appears that April 10th is likely capped, but the Local TV met mentioned that any storm that will be able to break the cap will become severe very quickly.

It also appears that April 13th is out of the equation for my area on the Local TV forecast as well, because the timing is off, but April 12th's timing appears to be perfect for an outbreak, & strong destabilization from the Daylight heating will weaken the cap.

EDIT: Forgot to mention that the Cap must be at the right levels for a solid outbreak, if it's too weak, then the storms are more likely to be linear & a smaller tornado threat (Unless a QLCS outbreak is expected), & if it's too strong, no storms will be able to develop. It appears that the cap must be strong enough to only allow the strongest updrafts to become the Supercellular, but weak enough to allow them to develop. (And if we don't want an outbreak, then a very strong or very weak cap will mess up the forecasts)

Edited April 9, 2022 by Iceresistance

[ClicheVortex2014]

0z NAM for 12z Tuesday is in. Beautiful loaded gun profile in central KS and OK. That 20C inversion at Wichita and OKC is suspicious though. May, probably not a big deal. April? Ehh

 

Wichita, KS

 

Topeka, KS

 

OKC

Edited April 9, 2022 by ClicheVortex2014

[Ingyball]

42 minutes ago, ClicheVortex2014 said:

0z NAM for 12z Tuesday is in. Beautiful loaded gun profile in central KS and OK. That 20C inversion at Wichita and OKC is suspicious though. May, probably not a big deal. April? Ehh

 

Wichita, KS

 

Topeka, KS

 

OKC

I guess the main thing to look for will be if this system has any mid-level cooling. Otherwise that's definitely a strong cap. If it does break it could be quite explosive. 

[ClicheVortex2014]

Pinks are gone on GFS but it looks like capping is weaker

SW IA

Outside of Topeka

North-central OK