2022 Short/Medium Range Severe Weather Discussion

[Hoosier]

There were some 80-81 degree dews in Missouri/Illinois earlier, so the modeled dews of near 80 pooling along the front tomorrow seem doable, helping to aid the jacked up CAPE.

[nwohweather]

It's hard to overstate how thermodynamic the instability will be Monday and Monday night...you've got this pristine EML advecting in:



This impressively rich low-level moisture will be advecting into the Ohio Valley, southern Great Lakes, and Upper Mississippi Valley beneath the advecting EML:


Despite the outstanding thermodynamics, the synoptic forcing is fairly modest (some right-entrance support over the Great Lakes) and at the base of the EML will be very warm 700-850mb temperatures acting as a cap:

The cap will be breakable in a narrow zone along and just north of the warm front...but with weak synoptic forcing, more robust convective development and subsequent upscale growth will likely be heavily tied to MCVs leftover from tonight's convection moving out of the Plains. A strong MCV will likely spark a robust subsequent MCS from the Upper Mississippi Valley into parts of the southern Great Lakes, mid or upper Ohio Valley, central Appalachians and perhaps eventually the Mid Atlantic. Given the thermodynamics and shear in place, the potential would exist for such an MCS to produce enough wind damage to be considered a derecho. 
However, CAMs so far struggling to agree on a solution. This is likely due to how sensitive the set-up is to tonight's upstream convection and MCVs it leaves into tomorrow (along with perhaps some modest strengthening of the upper level jet streak glancing the region), along with multiple forcing mechanisms and a rich environment to work with. There may be multiple MCVs, and some modest lift feeding into the right-entrance quadrant glancing the region may also aid some in allowing for convection that initiates to grow upscale:

Can note the multiple subtle vorts/perturbations drifting out of the Plains into the Upper Midwest and Great Lakes as a result from tonight's convection in the Plains...these will likely be very tied to where new activity initiates on Monday.

Can also note the right-entrance quadrant of a jet streak glancing the region, along with some hints that whatever upper level outflow occurs from convection over the Upper Midwest or Great Lakes may positively feedback with that for a time. 
If multiple rounds initiate at about the same time Monday afternoon or evening, there could be enough competition to lower the potential for any one cluster to turn into a particularly long-lasting and potent wind producer. 
Overall, my gut feeling is that at least one cluster will be dominant enough for a time to produce a pretty good swath of wind damage, but this could happen anywhere from the Upper Mississippi Valley to the lower Great Lakes, mid and upper Ohio Valley, central Appalachians or even Mid Atlantic between Monday afternoon and Tuesday morning. Potential exists for a higher-end event to be sure, but several ways it's at least somewhat limited. The MCV running east/southeast quickly may cause initiation earlier than optimal towards the Ohio Valley, slowing moisture/instability return farther north and also not taking full advantage of the environment coming together. Multiple areas of initiation at the same time could limit longevity of anything really potent, as there'd be too much competition eventually as stuff grows upscale. The greatest potential for a derecho to playout would be if initiation occurred mid-late afternoon in the Upper Mississippi Valley with one relatively dominant cluster and little out ahead of it, with the activity spreading through the southern Great Lakes into the evening and into the mid-upper Ohio Valley late evening or towards the overnight.
Given rich theta-e air feeding in from the southwest through Monday night, if we do see one or more MCSs producing robust cold pools, back-building and flash flooding may locally become a problem as the moist and unstable air would get lofted over the shallow cold pools by the low-level jet overnight, possibly causing back-building.
Any initial cellular convection would have a large to perhaps very large hail risk given the robust EML and huge instability...some tornado risk too, both with any initial supercells and with any more robust bowing segments that may play out as stuff grows upscale. 

It’s essentially a Louisiana airmass combining with Midwest dynamics, should make for a hell of a show. Glad you finished touching on the hail threat, with lapse rates approaching 8° it’s definitely a larger threat than usual for this region of the country.

[Chicago Storm]

There is not one CAM that has a handle on the situation as of the 0z runs.

[Chicago Storm]

Not in our sub-forum, but there was a heat-burst with the small MCS/MCV in KS not too long ago.

Oakley, KS (KOEL) peaked at 94/29 with a 56MPH wind gust.

[Hoosier]

11 minutes ago, Chicago Storm said:

There is not one CAM that has a handle on the situation as of the 0z runs.

Suggests that observational trends may matter even more than usual.

[Hoosier]

New day 1 outlook kept it at slight risk.

No guarantees, but I feel that it's highly likely/almost inevitable that we'll get an upgrade when the uncertainty lessens.  Setup is certainly capable of an ENH type event, if not more.

[HillsdaleMIWeather]

[HillsdaleMIWeather]

Enhanced introduced 

[SolidIcewx]

2 minutes ago, HillsdaleMIWeather said:

Enhanced introduced 

Looking spicy today

[buckeye]

Models are all over the place. 

[Baum]

amateur hour word for now: diffuse.

[geddyweather]

Models are not going to be of much help, going the old fashioned way seems to be the play today. CAPE gradient already developing along the warm front which should continue to advect NE-ward as the afternoon goes on. Storms in southern MN slowly getting together on the flank of the seemingly stronger of the MCVs would be what I'd keep an eye on currently. Current mean winds suggest this initial activity turns to the SE as it moves into central WI. SPC seems to support this becoming the main show as this is around where the ENH corridor begins.

[CheeselandSkies]

Sun back out in Madison after some overcast in the 7:30-8:30 AM timeframe.

Edit: 12Z HRRR essentially lost the bow echo again...what a joke.

[OHweather]

The models are still inconsistent with how they are handling/near term convection and how that impacts what happens this afternoon and tonight. The instability gradient will gradually shift east/northeast today and tonight, so the later we go before we see attempts at new upscale growth, the farther east/northeast the threat may play out. 

Seems like particular points of uncertainty involve how the ongoing activity currently over MN and northern IA, along with the rain over MO. If the rain over MO holds together and is able to eventually cause new storms to develop over the Ohio Valley this afternoon, that will slow the advance of the warm front and shave off the northern/eastern extent of the threat into tonight. Some CAMs have consistently shown that, though given how weak the activity is now and warming mid-level temps farther south we'll see if that can develop into much. 

The best synoptic forcing actually moves through the upper Midwest late this afternoon or evening and into the Great Lakes tonight. That will probably try to spark new convection along the instability gradient/warm front that would have a good shot at growing upscale, but the current activity over MN/IA adds quite a bit of uncertainty. That activity may become more surface based through this afternoon as it tracks towards the southern Great Lakes, and if that happened could grow upscale enough to either limit or delay the development of evening convection over the Upper Midwest. That's what the 12z HRRR did and why it suddenly shifted the derecho looking thing farther northeast and a few hours later. The 12z FV3 takes it to the extreme and actually makes the ongoing activity the dominant MCS and doesn't develop much behind it later today over the upper Midwest. However, if the ongoing activity stays elevated and lifts out before really growing upscale this afternoon, it could point to new initiation earlier that would probably dive farther southwest into this evening. 

Will probably need to watch trends for at least a few more hours before truly ruling out any of the shown solutions. 

[CheeselandSkies]

Stuff in NE IA/SE MN may get a boost from daytime heating before it comes through here, although it'll still be a few hours earlier than ideal and indications still are it will remain to the cool side of the warm front.

[frostfern]

It's really up in the air at this point.  If the elevated stuff currently over southern Minnesota reaches my side of the lake this afternoon there could be a supercell or two that becomes surface based.  The surface wind will certainly be backed along the warm front, pooling some higher dewpoints up against the lake meso-high.  Even without discrete cells, a lake-breeze / warm-front combo can produce QLCS tornadoes and/or mesocyclone wind damage.  That has happened more than once here, even later at night.

[Hoosier]

Oy vey.  Was hoping for more clarity at this point.  

[Baum]

my fears of June 30,2012 redux are beginning to subside.

[CheeselandSkies]

5 minutes ago, Baum said:

my fears of June 30,2012 redux are beginning to subside.

This sub is weird because different parts of it can experience the same season so differently. I remember 2012 as the most boring and stormless summer of my adult life; all those derechos went south/southeast of here. I've experienced a lot more thunderstorms this year than I had by this point in 2021 (although chasing is a part of that, since I drove to some storms I wouldn't have experienced at home), while others like @hardypalmguy are still getting the shaft.

[Hoosier]

Fairly widespread 80-82 degree dews in central/southern IL now helps the case for building extreme CAPE and trying to overcome capping later as this airmass advects farther north.  

[Powerball]

Y'all should already know, these setups rarely come easy.

[beavis1729]

3 minutes ago, Hoosier said:

Fairly widespread 80-82 degree dews in central/southern IL now helps the case for building extreme CAPE and trying to overcome capping later as this airmass advects farther north.  

Yep. The dew at ORD has already increased by 14 degrees over the past 4 hours (49 to 63)...with much more to come. And the dew at IKK is up to 75.

[CheeselandSkies]

13Z HRRR run put a supercell practically right over my house. 14Z goes back to snoozer for WI/IL/most of IN, with MI/OH/extreme NE IN action not getting going until late.

[Hoosier]

Flirting with a capping problem, but 

Northern IL

[frostfern]

5 minutes ago, CheeselandSkies said:

This sub is weird because different parts of it can experience the same season so differently. I remember 2012 as the most boring and stormless summer of my adult life; all those derechos went south/southeast of here. I've experienced a lot more thunderstorms this year than I had by this point in 2021 (although chasing is a part of that, since I drove to some storms I wouldn't have experienced at home), while others like @hardypalmguy are still getting the shaft.

The Morch, April, May had some amazing lightning shows and of course the surprise tornado.  After that it was just off-and-on heat, underperforming dewpoints, and weak dry cold fronts.  Spring was interesting, summer was boring.  Lately it has been the opposite.  Most severe opportunities are mid-June or later... more like typical climatology.

[Powerball]

8 minutes ago, frostfern said:

The Morch, April, May had some amazing lightning shows and of course the surprise tornado.  After that it was just off-and-on heat, underperforming dewpoints, and weak dry cold fronts.  Spring was interesting, summer was boring.  Lately it has been the opposite.  Most severe opportunities are mid-June or later... more like typical climatology.

In 2012, August finally cooled down, but I remember May through July being a wall-to-wall torches as well while April was fairly pedestrian. If I'm not mistaken, 2012 ended up being the warmest Summer on record in Detroit at the time, even surpassing 2011. 

Detroit was closer to the NE edge of the ridge as well, so we also had more severe episodes than maybe your area (although the derecho was a wide miss to the south).

 

[frostfern]

I have never seen a 30 C at 850 mb over a low spot like KC before.

[Chicago Storm]

Looks like activity will generally be limited to MI/NE IN/OH, with development that occurs much later today.

The pair of MCV’s that have been of focus are poorly timed and will have ended up tracking on an unfavorable trajectory to be useful.

Would expect to see some fairly significant adjustments in the next two SPC SWODY1 updates.

[frostfern]

14 minutes ago, Powerball said:

In 2012, August finally cooled down, but I remember May through July being a wall-to-wall torches as well while April was fairly pedestrian. If I'm not mistaken, 2012 ended up being the warmest Summer on record in Detroit at the time, even surpassing 2011. 

Detroit was closer to the NE edge of the ridge as well, so we also had more severe episodes than maybe your area (although the derecho was a wide miss to the south).

 

Summer 2012 was extremely warm, but it was a dry heat most of the time.  Rain was very hit and miss with all the post-torch cold fronts because dewpoints were mixing down into the upper 50s a lot in the afternoon and the lake shadow effect was strong.  When gulf moisture did occasionally make it north of the OV, the MCS track was mostly south of Michigan.

[CheeselandSkies]

18 minutes ago, Chicago Storm said:

Looks like activity will generally be limited to MI/NE IN/OH, with development that occurs much later today.

The pair of MCV’s that have been of focus are poorly timed and will have ended up tracking on an unfavorable trajectory to be useful.

Would expect to see some fairly significant adjustments in the next two SPC SWODY1 updates.

To the extent that any CAM wasn't awful with today, HRRR portrayed something like this with every other run or so.