Where. If you mean any of the resorts in Bulgaria you can't tell until closer to the time and I mean a week beforehand. Only thing you can safely say is that you will be able to ski.
this is one of those how long is a piece of string questions, last year in pamps was good coverage to start with then we got rain and the bottom part of the mountain was a bit patchy, we lost two days one due to heavy rain and one due to power problems and lifts were closed but had a great time. Bansko shouldnt be a problem, but then the other year in italy there were worries in Jan there wouldnt be enough snow for the olympics so you never know!!!!!!!!