Winter weather has hit the northeast with record snowfalls in December, January and on track for more snow in February. I have gotten many calls from sellers and past buyers with concerns about ice damming on their roofs. The best advise I can give is to keep you roof edges free of snow build up and if you have already had ice pockets form and large icicles please be very careful in trying to remove them. Forcing them off roof edges could damage your shingle and gutters. You may have to wait it out until the ice melts and keep a close on on interior drips. I have known roof shingles to settle back down after the ice is gone and then you may simply be left with interior clean up.
If the condition is severe of course call a qualified roofer. Think spring everyone!