Yep, the valve cover gaskets are a common problem. I would blow out the snow as already suggested before it can melt and cause rust or drip in further. Once thats done with all the spark plugs removed spin the engine over a few times(by hand) to make sure no water is in the cylinders. Then the last step when its all back together in the car and running do an oil change right away, and maybe even another oil change very soon.
Good luck and stay warm.