06 outback traction question

I have an 06 Outback wagon with 28k miles on it. It still has OEM Bridgestone tires that came with the car. The tires appear to have plenty of treadware left.

I live in northern Michigan where snow averages 150"/year. Of late we have two periods of very slippery road surfaces. No snow, just slick; maybe black ice.

When I drive it during these conditions, I notice a definate movement of the vehicle where it seems to be sliding side to side ever so imperceptilby. The sensation is almost like the vehicle is floating. Others in the vehicle have noticed too. It's almost as the wheels are hunting for the best traction.

Is this sliding/movement sensation common? If not, any ideas as what would cause this? And the fix?

This has happened to me twice and it very disconcerting. I have had other 4wd and awd vehicles and never had this happen before.

Any thoughts would be appreciated.

if it is indeed black ice most cars would slide a little...nature of the beast... but chances are its the crappy tire selection that subaru has made for years... i know from my own personal experience that those bridgestone tires are horrible in almost all conditions especially snow... my suggestion get a good set of tires... im sure you will be happy with the result!