Too early to give you the lowdown on what's open and /or the conditions of the runs, however I can tell you that the cannons are still on and it looks like it will be a beautiful (albeit very cold) sunny day!
I will post in about an hour once the lift operators have done their first run and let you know the conditions....
According to BoroSport website (http://www.borovets-bg.com/en/tracks/) only 3 runs and the snowpark are closed. It says it was updated today, anyone know if this is indeed kept accurate?