On average, March is the month with the largest monthly snowfall.
November - 29 inches
December - 33 inches
January - 52 inches
February - 55 inches
March - 57 inches
April - 24 inches
Source -
http://www.killington.com/winter/mountain/mountain_info/historical_weather
That said, the past few seasons have not featured the normally hearty March storms.
You're best bet for skiing powder in the east is to keep a flexible schedule and become a weather nerd. Remember that the difference between the best storm and the biggest bust can happen very dynamically and the ability to change plans on short notice is huge.