Discussion... At around 11 PM- 1 AM CDT, EHI (instability and spinning index) will spike in the area noted above. At the same time, shearing in the atmosphere will appear to the tune of around 50 knots in some levels from the surface to that level in the atmosphere. However, here's the thing: that will only be happening in the Surface-to-500 millibars and no other levels. It would be ideal to have more shearing in other levels of the atmosphere. Instability will be elevated, to the point of around 1500-2250 j/kg. However, it will only be elevated in western areas of the TornadoTrack.
So, why did we put up a pretty good tornado threat? Because of the front and surface winds. Surface winds, while weak, will be haywire, and that enhances the tornado threat. That, combined with the EHI could make for a potentially tornadic situation.
Today is like one of those 'it-happens-or-it-doesn't' days. There certainly is potential, but there's also potential for this situation not to happen.