2015-06-20 EVENT: IA,IL,WI,MN,MO

[Jared Stenerson]

Saturday is starting to look interesting. With a jet streak sitting over southern WI/Northern IL there should be sufficient forcing for ascent in the right entrance region in eastern Iowa. Also have a 850 mb LLJ of 30-40 knots progged to be over the SE half of Iowa. These combined should make for 0-3km SRH values in the 200-300 range. Add this to the possibility of 3000+ J/kg of SBCAPE and it could be a decent day. Will probably play the outflow boundary from the early convection in MN.

 

[Adam Lucio]

Im not a huge fan of the overall surface pattern, as latest guidance seems to shunt critical surface convergence/features further into SE IA with a more diffuse surface low. Nevertheless, strong instability looks possible as long as Bill remnants don't cut off the good return juice after a cold front slides through the region tonight. Available speed shear is impressive for this time of year though, and with forecast cape values near extreme levels. A potential outflow boundary could serve as a focus for renewed development and given the strong speed shear I would except a pretty intense line of storms to move south/southeastward across eastern Iowa and perhaps into Western/Northern Illinois.

Not seeing much in the way of supercell potential given the largely unidirectional shear, but with an outflow boundary and high CAPE anything is possible. I plan to be out.

 

[Ben Holcomb]

Obviously the instability is looking great per the latest 00Z NAM with 5000 J/KG of CAPE in Southern Iowa/Northern Missouri. The 500mb flow is actually quite nice, especially for this time of year.

As Adam touched on, the surface pattern leaves a lot to be desired, and with a departing anvil level jet I wonder if there will be any negative effects, especially the further south you get. Nevertheless, it's a tempting day to take a drive up I-35, especially considering the double play (Sat & Sunday)

 

[chrisbray]

It's looking more and more like the cap will hold all day until evening and then spawn an MCS along the Missouri/Iowa/Illinois border regions. NAM seems to show really weird surface pattern and I am not sure if it just isn't handling it right, but if it verifies, surface winds start out great but by the time the cap breaks they weaken and veer. I was hoping that some of the other potential local setups would pan out next week, but those are looking worse and worse as after this weekend we basically are stuck with westerly 850s. I may go ahead and make a play Saturday out of desperation

 

[chrisbray]

I doubt anyone is going to make a reports thread for yesterday, so I thought I would post my lightning shot I got local from some elevated storms before the man MCS hit town.

P6204543 by chris bray, on Flickr