I'm having a hard time remembering what the cloud cover/precip situation was just ahead of the Sept 2012 event. Based on the SPC events page, it looks like that might have been an event that started earlier in the day. We had mesoscale discussions by mid morning it seems.
It seems the guidance wants to track the low nearby or even to the southeast. The low being SE of us is going to probably nix any severe potential. We'll need to see if that trends back north and west a bit.