July 17-19 Severe Weather

[Hoosier]

Between the 3 km NAM and recent HRRR, something is going to be massively off later on.  3 km NAM does fit the expected scenario better.

[Chicago Storm]

8 minutes ago, Chicago Storm said:

Struggling to maintain, with shear lacking and best flow north.

This is probably the best it'll get.

And just like that, it's steadily fading now.

[Chicago Storm]

2 minutes ago, Hoosier said:

Between the 3 km NAM and recent HRRR, something is going to be massively off later on.  3 km NAM does fit the expected scenario better.

ARW/NMM/NSSL all bring in a fading MCS later, so that's likely the route to go. Not expecting any severe threat with it at all.

[Stebo]

25 minutes ago, Hoosier said:

Between the 3 km NAM and recent HRRR, something is going to be massively off later on.  3 km NAM does fit the expected scenario better.

Of the two handling the current situation the HRRR is doing better. 

[Indystorm]

I'll take a stab and say that both referenced models may be slightly off.  Yes, I expect t storms in Chicago metro in the wee hours of the morning, but SPC in their mid day discussion says they expect rapid t storm development in the Upper Midwest in the 20-23z time period and possibly the extension of the enhanced more se into se MN and central WI.  I didn't think the models had the storms initially firing that early in the time period.

 

[Hoosier]

16 minutes ago, Stebo said:

Of the two handling the current situation the HRRR is doing better. 

Here's what it has at 10z Sun.  No complex anywhere near southern WI, northern IL, southern Lake Michigan, etc.  Seems unlikely given other models (and the Euro which has had storms moving into the aforementioned area for days now)

 

[Chicago Storm]

HRRR failed miserably last night, and will be doing so yet again tonight.


.

[Indystorm]

Looks like our lone cell south of Rockford may be strengthening once again.

[SchaumburgStormer]

3 minutes ago, Indystorm said:

Looks like our lone cell south of Rockford may be strengthening once again.

Velocity showing some nice gusts 

[Indystorm]

Now svr warned for DeKalb county.

 

[wisconsinwx]

Perked up right before the lake with a very solid garden variety storm.  Tons of heavy rain and lightning, about 40mph gusts.

[Stebo]

30 minutes ago, Hoosier said:

Here's what it has at 10z Sun.  No complex anywhere near southern WI, northern IL, southern Lake Michigan, etc.  Seems unlikely given other models (and the Euro which has had storms moving into the aforementioned area for days now)

 

Yeah I am just going on the currents comparatively. Who knows what happens tonight at this rate

[RyanDe680]

Went from meh to zzzzzzz

[snowlover2]

They expanded the slight risk for tomorrow to now include se MI, most of Ohio and most of central IN.

Quote

...Great Lakes and Ohio Valley region...

   A shortwave trough will move through the Great Lakes on Sunday
   accompanied by a cold front. By 12Z Sunday the front should extend
   from a surface low in Ontario, southwest through the upper Great
   Lakes and central Plains. This boundary will move east and southeast
   during the day, likely extending from the lower Great Lakes through
   the Ohio Valley. A moist boundary layer with upper 60s to around 70
   F dewpoints will reside in the pre-frontal warm sector, contributing
   to moderate instability with 2000-2500 J/kg MLCAPE as the boundary
   layer warms. Thunderstorms will likely be ongoing, mainly across
   portions of MI. It is possible some of this activity might pose an
   ongoing threat for a few strong wind gusts, but it will most likely
   weaken during the morning. Additional storms are expected to develop
   along the cold front and residual outflow boundary across the OH
   Valley region. This area will reside south of stronger winds aloft
   with weak vertical shear expected. However, the thermodynamic
   environment may be sufficient for a threat of isolated locally
   strong wind gusts with multicell lines and clusters during the
   afternoon. 

 

[Powerball]

17 minutes ago, snowlover2 said:

They expanded the slight risk for tomorrow to now include se MI, most of Ohio and most of central IN.

 

Called it.  

[UMB WX]

2 hours ago, wisconsinwx said:

Perked up right before the lake with a very solid garden variety storm.  Tons of heavy rain and lightning, about 40mph gusts.

Cool and unexpected little event.  Gust were dam close to 50 it seemed.   She got a little hairy when it moved through. Power outages were dancing through my head. 

KMWC @ 54mph gust

KMKE @ 47mph 

[Chicago Storm]

There is not a single piece of guidance that has a handle on the current situation over the region.

[purduewx80]

That right-mover near Minneapolis should be poised to follow the MLCAPE gradient into WI. Often these supercells grow upscale into an MCV, so this is more than likely the start of the MCS the Euro has been advertising. 

[OrdIowPitMsp]

^ That cell has a tor warning and has been producing quarter size hail across the north metro. Looks like a line is trying to develop but probably will come together east of me. It's sunny in my backyard

[Stebo]

1 hour ago, Chicago Storm said:

There is not a single piece of guidance that has a handle on the current situation over the region.

HRRR/12kmNAM aren't far off, all those models blowing up massive MCSs by now are definitely wrong though.

[Stebo]

850mb temp of 22-24 and moreso 700mb temps of 14c would cap nearly any environment though and that is what you have from SE MN down to SE NE.

[purduewx80]

Nice soundings out of MPX (Minne) and DVN (Quad Cities) this evening. The classic 700-500mb lapse rates don't necessarily tell the story; LR are very steep just below there. Looks like the capping inversion was near 850mb at DVN and around 800mb at MPX. 

[Chicago Storm]

2 hours ago, Stebo said:

HRRR/12kmNAM aren't far off, all those models blowing up massive MCSs by now are definitely wrong though.

From worst to first.

HRRR was horrid last night, but it easily the closest to reality this evening.

[Hoosier]

LOT evening update sounded fairly uncertain about convective evolution.

[Stebo]

3 minutes ago, Hoosier said:

LOT evening update sounded fairly uncertain about convective evolution.

I don't see the 3km NAM being right at this point, so we could eliminate that one.

[Stebo]

The 12k NAM is a bit better but I don't know if I buy the front being dragged so quickly East with no significant convection. The evolution of the model is right but I would take what happens overnight and tomorrow and drag it back West/Northwest about 100-200 miles.

[purduewx80]

Might have to rely on that shortwave in SW Iowa or the cluster in KS/NE to help light up the front tomorrow morning. 

[Malacka11]

Just got home from work, and it's a total cumulus/lightning fest right now. Clouds are mushrooming all around me

[Powerball]

Looks like clear skies ahead of the QLCS. Should allow for quick heating.

The more interesting thing to see will be if the QLCS maintains its integirty and reintensifies for a formidable severe threat. The 06z NAM certainly hints at this outcome.

The instability is already there, and good moisture advection is ongoing.

[A-L-E-K]

Best climo