|American GFS model MSLP anomaly forecast for 10 days|
|European ECMWF model 500mb anomaly forecast for 10 days|
General atmospheric flow in both images is highly meridional, and the lack of a positive tilt (highest vorticity pointing towards the southwest) means that this system should quickly occlude and shoot north into the Plains towards Canada. When this occlusion happens, an accompanying cold front is likely to begin forcing the massive high pressure system out. Based on temperature forecasts from American model and European ensemble system, temperatures surpassing 60 would be common in and south of the Great Lakes. This could set the stage for a severe weather event. European model itself has cities like Chicago and Des Moines flirting with the upper 70's as the high pressure system takes over as illustrated in the above images, while the American model has those cities closer to the 60's.