Any major body of water, including the ocean, can experience snow. If temperatures are cold enough, snow forms over warm bodies of water as cold air moves into the area.
Cool air over warm water causes rapid condensation. The warm, wet air at the water's surface rises and begins to cool down quickly, forming snow clouds in cold temperatures. When this phenomenon occurs over a lake, it is called lake-effect snow and can lead to heavy snowfall and dangerous weather conditions. When it occurs over the ocean, it is considered ocean-effect snow and usually results in weaker storm systems and smaller snow totals.