Now the weather is getting colder your PS fluid is thicker first thing in the morning.
I would suggest that you check the tension on the PAS belt. I think that is what you are seeing smoking as it slips.
Probably better to replace the belt if this has happened much as the heat generated when it has been slipping could have carbonised the pressure surface and this would have taken on a polish. Once polished you will never get it to return to origional "grippy" finish.