What Gives?

Andy, that radar isn't a CURRENT radar! Check out radars for eastern MT on NCAR, CoD, or another of your choosing -- there are plenty o storms in easern MT.
That's what the radar looked like when the watch was issued. Note at the top "initial radar".

The portion that reads "Initial Radar" is a link to click, which will give you the radar when the watch was issued. That is not the first radar image.