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Severe Weather 4/17/26

Doubt they will pull a moderate risk. Every cam would have to consistently show the same outcome, it can happen. But it doesn’t really matter. CIG2 is effectively a moderate risk but low certainty.
Moving on though, looking at the OWS at first light, other than a small area of lake breeze fog, theres not a single cloud deck in the sky.
In this case, it’s best to trust cam models that show the highest surface temps (specifically). The solutions showing temps peaking in the low 70s in Wi are most certainly erroneous at this point.
Expect actual surface temps to peak in the high 70s to even low 80s. This definitely would favor a more organized discrete mode and even higher cape values.
Any chance at overmixing in this event?
 
Any chance at overmixing in this event?
Nope, honestly you would want “overmixing” to really cut down on crapvection.
And the more I look at skew-Ts the more I think the messy storm mode solutions are less on the table.
The latest 11z hrrr is incredible messy but still tornado productive.
But just a single look at what it’s modeling for the vertical profile, it’s easy to see why.
It simply has a very weak to non existent cap. The entire confluence band grows upscale before the cold front itself even convects. Which is a red flag because that’s simply not how inversion layers or forcing mechanisms work.
Looking at current skew-Ts, the edge of the inversion layer is currently in middle IA and advecting north, unless it magically stops its motion then will it be possible for a confluence band to convect before the cold front does. Obviously this is very unlikely to happen.
On uncertain days like this, you have to look at the current reality of what’s going in the mesoscale. You can spot where it’s located by looking where there’s a sudden spike in mid level dry air.
This will continue northward and likely will terminate most crapvection when the forcing mechanism arrives at the yet to be seen confluence band.
 
Also it’s worth noting most cams have only one or two supercells in the OWS and some don’t even bother to convect the OWS at all, keeping it purely a QLCS event.
Then here we have the 11z hrrr having an entire squall line in the OWS.
Gonna let you guys decide which model is going ham on their crackpot.
 
From a chasing perspective, I think setting up around Ponca city is the best option. Northern mode probably has a higher tornado risk but the southern risk looks much better for chasing. It’s slightly conditional but I think we get super cells in OK/kS for a couple hours at least.
 
Also it’s worth noting most cams have only one or two supercells in the OWS and some don’t even bother to convect the OWS at all, keeping it purely a QLCS event.
Then here we have the 11z hrrr having an entire squall line in the OWS.
Gonna let you guys decide which model is going ham on their crackpot.
What outcome do you think is most likely? I know you've already said the event should be more discrete than some models portray but in terms of the event itself, what do you think would be the most likely outcome?
 
What outcome do you think is most likely? I know you've already said the event should be more discrete than some models portray but in terms of the even itself, what do you think would be the most likely outcome?
When making a forecast, it’s best to go with the middle route when there’s major discrepancies in cam model outputs.
I think the most likely outcome is that we get one or two storms that manage to initiate in the OWS, and obviously they will be capable of all hazards including strong tornadoes. The cold front will be bringing in the QLCS threat right behind.
 
yeah, although the enhanced stretched out a bit east to chicago
On that topic, interesting to see the stronger QLCS/embedded TOR signal further into the metro.

In general, have a feeling that even if today isn't a necessarily large outbreak with discrete sups, seeing a strong signal for one to two dominant storms and that may have the potential to produce something big.
 
I know we are in nowcast mode. After 3/15 last year, if all the CAMS are pointing or trending to a more linear presentation, I’m inclined to lean towards that solution.

Much different look being depicted this morning vs yesterday. Can see why the SPC stuck with enhanced.

Plains may actually end up being the play today.

Also, this is a good example of why that tweet posted by Jaydon Shaw was so stupid yesterday. Posting one CAM run the day before and hype posting it only for it to do the uno reverse the very next day. There’s a reason local Mets don’t really start messaging on severe weather until 1 or 2 days prior.
 
Here’s yet another red flag the hrrr is on bs pack.
By 10am, it has most of northern IA blowing up with convection. It will be 10 less than 20 minutes from now and here how it looks in reality.

Edit: it’s now 10am, and not a single storm cloud in sight. Safe to say we’ll have to rely on visual observations now.
 
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