Severe threat 6/10-6/12

[King James]

Nothing but sunny skies here in IKK since daybreak, thought it might be an overcast start to the day

[frostfern]

42 minutes ago, Harry Perry said:

Pretty “meh” feeling over this way. 
 

Lake Michigan and an overturned atmosphere  (downstream) along with debris clouds vs an unusually strong June system. Lots of bust potential here. If things hold out or redevelop over this side of the pond then could be a big evening but timing is getting later and later and models looking messier/disorganized. 
 

I feel pretty confident in the Chicago area for some heavy weather after 7-8PM. 12z HRRR looks ugly. 

Overnight crapvection shunted the real instability south as usual.  Maybe 1-94 but I’m hosed up here.  Michigan.

[homedis]

30 minutes ago, Chicago Storm said:

I believe we will see some changes regarding expectations for today.

Let the HRRR catch up to reality over the next few runs, and we’ll likely see a clearer and different picture painted.

If this initial MCS stays further south, you think the warm front may be closer to I-80 corridor or even further south for the next round? LOT AFD sort of alludes to this.

[Chicago Storm]

If this initial MCS stays further south, you think the warm front may be closer to I-80 corridor or even further south for the next round? LOT AFD sort of alludes to this.

Quite possibly.

The latest HRRR already has a better handle, and never gets the WF back to even I-80.

[King James]

IKK is the spot

[yoda]

 

Mesoscale Discussion 1086
   NWS Storm Prediction Center Norman OK
   0953 AM CDT Thu Jun 11 2026

   Areas affected...eastern Iowa into northwest Illiniois and northeast
   Missouri

   Concerning...Tornado Watch 311...

   Valid 111453Z - 111630Z

   The severe weather threat for Tornado Watch 311 continues.

   SUMMARY...Severe wind gusts remain likely across eastern Iowa,
   northwest Illinois, and northeast Missouri. A tornado risk may
   develop from northeast Missouri into west-central Illinois.

   DISCUSSION...An MCS with a history of producing measured severe wind
   gusts continues to quickly move  across eastern IA. Two main surges
   are evident within this north-south line, with the southeast IA
   portion currently stronger than the section moving into northeast
   IA. Meanwhile, a trailing portion of the MCS extends southwestward
   into northern MO, where backbuilding is occurring.

   It appears the environment farther east across IL and southern WI
   will need to undergo significant destabilization for this existing
   MCS to remain severe into the afternoon. 12Z soundings from DVN and
   ILX show a stabilized air mass from the overnight MCS, with GPS PWAT
   sensors indicating a deeper moisture gradient across central IL.
   However, visible satellite shows strong heating occurring ahead of
   the MCS, and modest southwest winds will allow for moisture to
   gradually return northward across IL and vicinity.

   Some tornado risk exists as well, especially along the
   southern/southeastern fringe of the MCS. Here, 0-1 km SRH will
   remain strongest, and the environment should become more favorable
   later in the day as the air mass become more volatile.

   ..Jewell/Gleason.. 06/11/2026

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...LOT...ILX...LSX...DVN...DMX...EAX...

[hawkeye_wx]

No severe here, but we did get torrential rain.  I got a very quick 1.25".  At its peak it was close to 4"/hr, the heaviest rain I've seen in a while.

[Tim from Springfield, IL]

39 minutes ago, yoda said:

 

Mesoscale Discussion 1086
   NWS Storm Prediction Center Norman OK
   0953 AM CDT Thu Jun 11 2026

   Areas affected...eastern Iowa into northwest Illiniois and northeast
   Missouri

   Concerning...Tornado Watch 311...

   Valid 111453Z - 111630Z

   The severe weather threat for Tornado Watch 311 continues.

   SUMMARY...Severe wind gusts remain likely across eastern Iowa,
   northwest Illinois, and northeast Missouri. A tornado risk may
   develop from northeast Missouri into west-central Illinois.

   DISCUSSION...An MCS with a history of producing measured severe wind
   gusts continues to quickly move  across eastern IA. Two main surges
   are evident within this north-south line, with the southeast IA
   portion currently stronger than the section moving into northeast
   IA. Meanwhile, a trailing portion of the MCS extends southwestward
   into northern MO, where backbuilding is occurring.

   It appears the environment farther east across IL and southern WI
   will need to undergo significant destabilization for this existing
   MCS to remain severe into the afternoon. 12Z soundings from DVN and
   ILX show a stabilized air mass from the overnight MCS, with GPS PWAT
   sensors indicating a deeper moisture gradient across central IL.
   However, visible satellite shows strong heating occurring ahead of
   the MCS, and modest southwest winds will allow for moisture to
   gradually return northward across IL and vicinity.

   Some tornado risk exists as well, especially along the
   southern/southeastern fringe of the MCS. Here, 0-1 km SRH will
   remain strongest, and the environment should become more favorable
   later in the day as the air mass become more volatile.

   ..Jewell/Gleason.. 06/11/2026

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...LOT...ILX...LSX...DVN...DMX...EAX...

ILX might as well locally extend Tornado Watch 311 to everything west of I-55.  Including Bloomington, Jacksonville and yes Springfield--in addition to the rest of the Peoria metro.

[Sciascia]

The currently running 15z HRRR is showing much less intensity for the IL/WI border area regarding the first round of storms at Noon/1pm. Lots of yellow, but no reds & purples.

[Harry Perry]

GRR AFD:
The question is does the convection survive all morning and push
across Lake Michigan during the mid afternoon hours. We will follow
the HREF for guidance on this. The HREF weakens the initial
convection as it moves towards or out over Lake Michigan this
afternoon. This will allow the main surge to move in this evening
out ahead of the main upper wave. If the first round of
convection survives and spreads into Lower Michigan this afternoon
that could modulate our event for the evening. We do not think
that is going to happen.

 

 

[Chicago Storm]

There's not a single 12z CAM that has a handle on evolution of the initial MCS.

[King James]

Moderate nudged south some?

Riding the Bloomington/Pontiac/Kankakee corridor

[ILSNOW]

Chicago NWS Izzi

CAM guidance remains very aggressive with a strongly unstable and
rather large warm/unstable sector ahead of the cold front, though
most CAMs do not seem to be handling the current size/magnitude
of the MCS and associated cold pool well. Recent observational
trends raise significant questions about how realistic the CAM
depictions are. Certainly, given the magnitude of the forcing, we
feel that at least some moderate destabilization will occur and
likely support a strongly forced QLCS developing along the cold
front this afternoon and spreading into northern IL this evening.
Magnitude of the recovery and subsequent destabilization across
northern IL is somewhat unclear ahead of this QLCS, but given the
strong forcing and unseasonably strong deep and low level shear,
there could a damaging wind and QLCS tornado threat even with
somewhat modest instability. Should recovery and instability be
more significant, like many CAMS show, then potential would
increase for a derecho/QLCS tornado threat this evening. We will
be closely monitoring observational trends this afternoon.

[homedis]

Looking to be more of a flash flood event for Chicago versus severe at this point. Not feeling confident for sig severe later.

[cyclone77]

First round quickly converted over to anvil rain on approach.

Let's see what round 2 does.

[Powerball]

What a messy setup.

Funny how the setup yesterday was quietly a lot cleaner, despite shear/dynamics being not as impressive...