Steve and I debate this all of the time. I've seen some literature defending both sides. I missed out on the snow this recent go-around and my lawn went bonkers the last couple of days as well. I think a deep soaking natural event is what really helped. Plenty of nitrates serve as condensation nuclei so I'm not sure how much of a difference there is between snow falling and melting on contact here versus accumulating a couple inches down there before melting. Like Steve says, maybe the slow release of the nitrates in the melting snow gives a steadier supply of food to the lawn over a 2-3 day span.
Regardless, we green.