Likes been said, snow is like a blanket of insulation. A heavy blanket. The weight also forces water up through cracks & holes making slush. Which weakens existing ice underneath and when it freezes makes poor white ice on top. Full of air like the snow. Not a good feeling to walk out on partially frozen slush. A thin layer of frozen slush, a layer of water (obviously above freezing temp.) and weakened ice underneath. Bad scenario. Likes been said also, a descent amount if ice isn't so bad, but on thinner ice, not good.