The Storm Prediction Center is monitoring the area for a possible watch, most likely a Severe Thunderstorm Watch.
According to their discussion, damaging wind and large hail would be the primary threat of any storms in the watch area. (I've been home sick the last two days so I haven't had a chance to look too deeply in to the models. I am going straight from their discussion.)
At 3pm, temperatures are widely spread. It is 55° in Farmington, Missouri and 73° in Carbondale, Illinois. Obviously, we have a cold front set up over the top of the area. Ahead of the front, dew points are in the middle 60's. Behind the front dew points are in the upper 40's to lower 50's.