Chris, I just registered today, and this is my first posting.
Get the wheel/bearing checked right away!! I had the same
symptoms you describe after replacing a set of lug nuts, with
cheaper, non-Subaru nuts (which are ~ $11 each). These
looked the same , but turns out these did NOT tighten the
wheel all the way down. It's possible instead of over torquing
the lug nuts (should be ~ 80 ft-lbs) they may be loose!! Jacking
up the car and checking the wheel should tell you. Bearings
typically would wear away slowly, not go bad all of a sudden
with your symptoms.