Pattern change leads to first cold front in more than a week, but does it bring severe weather?

It's been more than two years since my last blog entry, but we'll try to start this thing back up and maybe we can build a bit of a reader base. If there's anything you'd like to see more of in these entries, always feel free to drop me a line on Facebook, Twitter, or email. To the weather:

Over the last week, there's been little in the way of change in the atmosphere over Southern Illinois and really the entire Central U.S., but all that is getting ready to shift. Attached first is Sunday morning's 500mb chart. The thing to notice is the storm system that's been camped over the Lower Mississippi Valley has died off and high pressure over the Mid-Atlantic and a dominate ridge have become the pronounced features.

The ridge that is so pronounced Sunday morning, starts to break down early in the week as the overall pattern shifts. The mid-level southwest flow turns to a westerly flow that drops south over the Ohio River Valley with several pulses of energy riding the flow. (see below: note shortwave in the 500mb flow in South Dakota)

At the surface, this pulse of energy noted above will be riding a cold front set to drop south into Southern Illinois late Wednesday evening into Thursday morning. With models indicating surface CAPE (Convective Available Potential Energy) in excess of 2500J/kg, a LLJ pushing moisture north resulting in PWats pushing 1.90, and the increase in shear, the atmosphere may be able to sustain severe storms and needs to be monitored. In this day and age, forecasting has come lightyears from where it used to be, however, forecasting severe weather is still very challenging and finer details won't be available for a few days.