In the past, I combined what I knew about the weather with a guess as to how the school administration would react (emphasis on guess).
Now I have to add a third factor: an increasing randomness in the weather patterns.
Saturday's unexpected two inches is an example. No one really saw it coming until Friday night.
As the atmosphere heats up, the oceans heat up and the ice caps melt. The result is a change in wind and water currents. The old computer models have to change as well, and they aren't there yet.
However, I am going to go out on a limb with a forecast for Tuesday:
So, how about that weekend before Christmas? Larger storms are easier to predict, and it looks like a rainy monster next weekend. Sunday probably rain, changing to ice Sunday night.