The next 48 hours promise to be interesting ones around the Midwest. 2 separate pieces of energy will cross the central Midwest bringing the potential for thunderstorms. Severe weather is also possible, especially Wednesday when a significant round of storms is suggested in some part of my local area.
The first threat for convection gets underway late Tuesday and Tuesday night. A cold front will enter my local area towards evening and then slow as it eventually stalls Wednesday morning near the northern Missouri border. This part of the 2 pronged event could yield scattered strong to severe storms during that period. Shear profiles are marginal so the tornado threat is low until later Wednesday.
It's Wednesday where model data begins to struggle resolving several key issues in the severe weather equation. The problems are not at all unusual at this stage of development. Boundaries are going to be difficult to define until we see the outcome of Tuesday nights storms. Outflow from convectively generated cold pools will determine where the synoptic parameters are situated at peak heating Wednesday. That in turn determines where the best instability (CAPE) is established and where the greatest severe weather threat develops.
At peak heating Wednesday CAPE values (convective available potential energy) look like this on the EURO (my preferred solution)/
These values of instability are based in on highs and dew points that look like this on the EURO late Wednesday.
As I write this the Storm Prediction Center has this area highlighted for severe weather potential.
At this point there are too many unresolved variables for SPC to raise the risk. And, with the issue of convectively induced boundaries from Tuesday night storms in question, it will probably take until Wednesday morning before the true nature of the risk is revealed.
Thus, we wait and watch as the age old marriage of weather variables simmers in the pot! Stay tuned as we await the final product. Roll weather...TS