Severe WX Severe Weather Threat June 6-14

[andyhb]

Anyways, so about low level lapse rates. They are often only a major problem when a) there is not enough forcing for ascent and b) capping is too strong. Neither of those is the case today.

You also always need to factor in that 0-3 km lapse rates often include the base of the inversion, which is by definition going to decrease the lapse rate because it is warm air aloft.

 

[buckeye05]

Damage images coming in from the Dwight area tornado

 

[Kds86z]

 

[Grand Poo Bah]

User submission to Ryan Hall of the Streator tornado

 

[buckeye05]

Main tornado producing cell is now pushing into the tornado-weary Kankakee micropolitan area. Doesn’t look quite as menacing now, so fingers crossed.

 

[buckeye05]

With that said, this could be a productive cell merger in progress near Manteno. Bears watching to see how this unfolds.

 

[kcyalater]

down to one TOR. thankful!

 

[buckeye05]

In fact, all of the cells at the IL/IN border have hooks and mesos. We aren’t quite out of the woods yet.

 

[Grand Poo Bah]

There's still tons of OWS convection ongoing, and the trough is FLYING. I think we're going to really stretch the edges of the SPC risk area. As far as I can tell there's nothing stopping this lone cell in Indiana from popping off.

 

[buckeye05]

The Manteno cell appears to have multiple updrafts currently. If one becomes dominant, it could produce again.

 

[WeathermanLeprechaun]

Smaller updrafts = better ventilated supercells. Peak intensity method suggests 120-150. Prefrontals aren't done at all with significant t intense tornado threat.

 

[jiharris0220]

Today really reminds me of the April 2, 2025 Tornado Outbreak, as both of them really were make or break and relied solely upon the fact that their would be OWS supercells just out ahead of a powerful QLCS.
Both of those days had a very strong forcing mechanism impinging on little to no inversion layer, a very moist vertical profile and low LFCs.
What makes today different however is that the LLLR were very meager and upper level ventilation is weak, so there was even more uncertainty with this event verifying.
Most importantly, the boundary left behind from the afternoon MCS is what likely pulled today off. It’s pretty obvious the OWS supercells that managed to produce latched onto this boundary were there’s enhanced streamwiseness and backed surface winds. Only then could those storms sufficiently vertically stretch the low levels into usable vorticity.

 

[buckeye05]

New cell rapidly going tornadic near Beaverville

 

[WeathermanLeprechaun]

Beaverville, IL cell is looking highly dangerous with strong merger in its rear flank. Strong to intense tornado short term.

Edit: got the wrong town name for the cell I meant

 

[WeathermanLeprechaun]

Today really reminds me of the April 2, 2025 Tornado Outbreak, as both of them really were make or break and relied solely upon the fact that their would be OWS supercells just out ahead of a powerful QLCS.
Both of those days had a very strong forcing mechanism impinging on little to no inversion layer, a very moist vertical profile and low LFCs.
What makes today different however is that the LLLR were very meager and upper level ventilation is weak, so there was even more uncertainty with this event verifying.
Most importantly, the boundary left behind from the afternoon MCS is what likely pulled today off. It’s pretty obvious the OWS supercells that managed to produce latched onto this boundary were there’s enhanced streamwiseness and backed surface winds. Only then could those storms sufficiently vertically stretch the low levels into usable vorticity.
View attachment 53277

Also, smaller updrafts meant better ventilation for supercells. Had we got grungy HP messes like to the west, this event wouldn't have performed at all.

 

[buckeye05]

Man if that Crete cell goes, it will be in a bad spot. That’s encroaching on a densely populated suburban area.

 

[Grand Poo Bah]

There's still 3000 J/KG ML CAPE behind this QLCS too lol. 1800 SB CAPE

 

[jiharris0220]

Also, smaller updrafts meant better ventilation for supercells. Had we got grungy HP messes like to the west, this event wouldn't have performed at all.

Nine times out of ten, the smaller updrafts wouldn’t have worked out. (Especially with how high the shear is)
The low LFC is responsible for the skinny updrafts, even if laspe rates were higher, it wouldn’t have solved that specific problem.
In this case, the very strong forcing mechanism, (the 500mb jet max) combined with the lack of an inversion layer really came in handy.
And again, the left over boundary most certainly was the final nail in the coffin for a b#st scenario.
Good example of just how important it is to have favorable Synoptics and a lucky mesoscale setting.

 

[buckeye05]

Manteno cell merger seems to have been productive. If there’s another big inflow surge it could produce.

 

[warneagle]

Obviously small potatoes compared to what’s going on out west but we’re about to get rocked by a SVR-warned squall line here on the east coast