August 9-12, 2021 Severe Threats

[Chicago Storm]

1 hour ago, UMB WX said:

Sucks man.. still time to make it up to Caledonia.. i have no bbq or booze though.

can head up to the palm kingdom for that.

[UMB WX]

16 minutes ago, Chicago Storm said:

can head up to the palm kingdom for that.

Good times.  he snow gunned mountains to unboxing the palms in spring.  

Always got a kick out of his slant sticked snow totals to the NWS.

[Stebo]

Solid MCS here for the Detroit area, Detroit Metro 62, Selfridge 75, Ann Arbor 58, Pontiac 54, Willow Run 60.

[nwohweather]

My old stomping grounds were under three separate Severe T-Storm Warnings today, I don’t know if that has ever happened before. Lots of damage in the hometown by the 3 AM line, another line of severe storms hit the Toledo area around breakfast, and then this afternoon’s events.

[CheeselandSkies]

Sitting in Mt. Horeb, WI waiting on this severe warned mess. How anticlimactic after the seeming rapid ramp up in potential late this morning.

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[Malacka11]

11 minutes ago, CheeselandSkies said:

Sitting in Mt. Horeb, WI waiting on this severe warned mess. How anticlimactic after the seeming rapid ramp up in potential late this morning.

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Same boat here, a little bit farther west. 

[hawkeye_wx]

Cells are trying to pop along the front over here, but the cap is too strong.

[IWXwx]

4 hours ago, purduewx80 said:

 

 

2 hours ago, Hoosier said:

Up to 85/67 at ORD.

This outage sucks.  

 

[CheeselandSkies]

Same boat here, a little bit farther west. 

Storm near Mineral Point looks momentarily interesting on radar.

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[Mogget]

Woot!  Just got the Tornado Warning screech over the iPhone!

[purduewx80]

Destabilizing very quickly now thanks to incredibly steep mid-level lapse rates and strong low-level moisture transport. I don't really see the stratus the SPC mentions in their latest discussion as a hindrance to an increase in TS development this evening given the advective processes ahead of several well-established mesocyclones.

Confirmed tornado east of Mineral Point now - in the worst spot for radar detection, but the meso is obviously impressive (via KDVN).

[Malacka11]

I saw it drop for literally ten seconds and retract again, still rotating hard

[Chicago Storm]

21 minutes ago, purduewx80 said:

Destabilizing very quickly now thanks to incredibly steep mid-level lapse rates and strong low-level moisture transport. I don't really see the stratus the SPC mentions in their latest discussion as a hindrance to an increase in TS development this evening given the advective processes ahead of several well-established mesocyclones.


Confirmed tornado east of Mineral Point now - in the worst spot for radar detection, but the meso is obviously impressive (via KDVN).

I believe they more-so meant it is a sign that the atmosphere is still somewhat stable to a degree, which meso-analysis supports (If you believe it).

0z DVN sounding coming in shows capping still in place as well, which is likely the reason the activity is struggling in the great environment across E IA.

Edit: I'll add that obviously we are still destabilizing a bit more.
.

[Malacka11]

Not sure what happened, this thing had a crazy looking mesocyclone for a few minutes and now it looks a like a bunch of innocent clouds. Hoping it can wrap up again but

[SchaumburgStormer]

Cap bust incoming. Yawn. 

[Chicago Storm]

19 minutes ago, SchaumburgStormer said:

Cap bust incoming. Yawn. 

Counting this morning, it was the 3rd quality day in a row... So it was bound to end at some point.

[Chicago Storm]

As mentioned before, the 0z DVN sounding shows capping is still in place.

[CheeselandSkies]

I saw it drop for literally ten seconds and retract again, still rotating hard

Argh, I probably could have seen this had I started going for the storm as soon as I took note of it, but I really didn't expect it to do anything and didn't want to backtrack further from home after making a big loop back from the Lake Delton area after an aborted attempt to get to the early cells to the north. I had of course just left Mt. Horeb eastbound for home and had to spin a frantic uie on 151. Hauled butt to Hollandale where it still had a neat looking rain free base with RFD cut but quickly died after that.

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[sbnwx85]

I was going to ask if storms could develop if the cap can erode after sunset. Latest SPC discussion answers that with a "maybe?"

Mesoscale Discussion 1492
   NWS Storm Prediction Center Norman OK
   0735 PM CDT Wed Aug 11 2021

   Areas affected...Eastern IA...Northern IL...Far Southern
   WI...Northwest IN...Southwest Lower MI

   Concerning...Severe potential...Watch possible 

   Valid 120035Z - 120200Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Storm coverage is expected to increase this evening, with
   at least an isolated severe threat into late tonight. New watch
   issuance is possible by 01-02Z.

   DISCUSSION...Earlier supercells over eastern IA, southwest WI, and
   northwest IL have weakened over the last hour, likely due to
   generally weak large-scale ascent and modest capping noted in 00Z
   DVN sounding. However, regional soundings and VWPs also depict a
   rather strong southwesterly low-level jet across the area, which is
   generally forecast to intensify further tonight as it veers to a
   more westerly direction. Storm coverage is expected to increase with
   time later this evening within this warm advection regime, as
   airmass recovery continues across northern IL/IN and a surface
   boundary moves southeastward across the region. 

   Even if storms remain somewhat elevated tonight, steep midlevel
   lapse rates and rich low-level moisture will still support large
   MUCAPE, with sufficient deep-layer shear for some organized storm
   structures. A mix of cells and clusters will be possible, posing a
   threat of at least isolated hail and damaging wind. A conditional
   tornado threat will also be present with any storm that can become
   rooted in the boundary layer, which would be most likely for a few
   hours this evening before MLCINH becomes increasingly prohibitive
   late tonight. 

   While some uncertainty remains regarding the convective evolution
   and coverage of the severe threat later tonight, watch issuance is
   possible by 01-02Z, in advance of the expected increase in storm
   coverage.

   ..Dean/Goss.. 08/12/2021

[CheeselandSkies]

1 hour ago, Malacka11 said:

Not sure what happened, this thing had a crazy looking mesocyclone for a few minutes and now it looks a like a bunch of innocent clouds. Hoping it can wrap up again but

It hit the stable air/stronger cap. Guessing you probably passed me/I passed you several times on County A near Daleyville?

[Malacka11]

1 hour ago, CheeselandSkies said:

It hit the stable air/stronger cap. Guessing you probably passed me/I passed you several times on County A near Daleyville?

Quite likely, we were driving a gray 2003 Civic

 

I have some low quality footage that I'll try to upload when I get home. Though the tornado only lasted for 10 seconds the supercell was incredibly picturesque. 

[CheeselandSkies]

1 minute ago, Malacka11 said:

Quite likely, we were driving a gray 2003 Civic

 

I have some low quality footage that I'll try to upload when I get home. Though the tornado only lasted for 10 seconds the supercell was incredibly picturesque. 

Red Toyota Corolla, had my phone on a dash mount running an app that lets me stream live video back to the Madison TV station I work for (when there's sufficient data coverage, which is spotty in that area, heck even basic voice is for me on US Cellular).

[A-L-E-K]

Looks like some cute garden variety moving in

[Malacka11]

3 minutes ago, CheeselandSkies said:

Red Toyota Corolla, had my phone on a dash mount running an app that lets me stream live video back to the Madison TV station I work for (when there's sufficient data coverage, which is spotty in that area, heck even basic voice is for me on US Cellular).

That sounds very familiar, my friend says he remembers one parked on the side of the road. Dunno if that was you though lol. Still cool to think about though

[Jim Martin]

 

[Jim Martin]

[michsnowfreak]

The squall line had about 70 mph winds as it blew through. Rainfall itself was nothing special, 0.34", but the storm itself was probably the most destruction we've had from a thunderstorm since May 3, 2018.

[Hoosier]

1 hour ago, A-L-E-K said:

Looks like some cute garden variety moving in

I watched a radar loop and wow, that thing fell apart fast.

[Malacka11]

In case anyone's interested, here are a couple horrible pictures that we managed to take . I'm pretty sure two distinct funnels are visible in the first picture. The entire thing presented more as like a mutli-vortex wall cloud that damn near just collapsed to the ground. Briefly, this condensation funnel emerged, but it lasted for literally less than fifteen seconds, and we were trying to get over a hill for a better view, hence why we couldn't get a halfway decent photo. In the second, equally low-resolution image, the entire base of the meso seems to be visible. It was quite the sight; my very first textbook supercell, and honestly, seeing the whole thing form was easily as exciting as the tornado itself. Unfortunately, I left my camera at home today, and the very rapid formation and movement of the wall cloud meant that there was basically nothing we could do to take decent pictures on our phones either until minutes after the wall cloud retracted again. T'was a good experience, but not one worth driving over 550 miles for. Granted half of that was picking someone up from Milwaukee. Didn't help that we left at like 12:30 either. We barely managed to get something worthwhile out of this trip. Dunno what I'd do if we would have gone out that far for nothing. 

Also, to the Wisconsin posters here... Wow. Your state is beautiful.

[CheeselandSkies]

Beautiful, but very tough to chase in except for a small area* which is manageable. Once you get into the Wisconsin River Valley, in northern Iowa/Sauk/Grant/Crawford Counties, fugheddaboutit.

Mad I probably could have gotten that tornado had I left for the storm about 20 minutes earlier, when I first thought it was starting to look interesting, but again, figured it would collapse (like it ultimately ended up doing) and really didn't want to get suckered further from home after what had already been a letdown of a day. At least from the point where I realized the storm was dying, I was like 20 minutes from home.

*Most of Dane County is relatively decent, except for the far southwest corner (which of course is where yesterday's storm tracked into just before it collapsed) and the immediate Madison vicinity where you have all the usual problems with metro chasing. Green/Rock, southern Columbia, Dodge, Jefferson and western Walworth Counties are OK terrain-wise, but southeastern Rock County into Walworth County the road network is really bad. Once you get into the Lake Geneva area, it's really bad trees lining the roads again. The rural parts of the far southeastern counties are OK, but you have limited space before you run into the metro areas of Milwaukee/Racine/Kenosha and then of course the big lake.

As I said basically anything along the Wisconsin River and the Driftless Area is horrible, which of course is where most of the best storms (including Boscobel) during this sequence have been.

The only significant tornado, to my knowledge, to track through that relatively small area of manageable chase terrain in recent decades is the Stoughton tornado of August, 2005.