Tornado Watch issued for western and central lower MI, severe threat likely to move eastward through evening

The Storm Prediction Center has issued a TORNADO WATCH for most of southwest lower Michigan as a very wicked looking squall line crosses into the state. 

I fully expect the severe threat to propagate eastward throughout the evening hours, as it will continue to be warm, humid and unstable.  I'm on the road right now, so unfortunately I can't delve any deeper.  Expext more info when I can delve deeper into model data and observations.