An interesting weather pattern will be setting up this week. We are moving into what many meteorologists call an "Omega Block." A quick explanation from the KSHB blog here:

"The symbol ω (lower-case letter) is used to represent what we call an Omega Block. A huge, unseasonably strong upper low is now forming over the western part of the nation.  It is helping throw up a big ridge in the middle part of the country which in turn is helping fuel a deep upper low over the Great Lakes.  Look below at the forecast map for Thursday morning and notice the letter omega":
     

This pattern would normal be very warm and dry for this part of the country, with the huge ridge of high pressure building all the way up into Canada. But this week, a storm system will get caught up underneath the flow, and will cause a warm front to set up to our south. We will have easterly breezes bringing in cooler air north of the front, while south of the front it will be very hot and humid. Map posted below.

This warm air trying to force itself northward into the cool air will likely cause showers and thunderstorms to form Wednesday night into Thursday morning. There could be some heavy rainfall. The GFS gives us between .5 and 1 inch of rain, while the NAM, posted below, gives up almost 2 inches! This will be very interesting to watch develop over the next couple of days, as the models want to keep rain in the forecast through Saturday!