I found this, which was intriguing since it relates back to what Grassley was tweeting about (frigid cold weather/ Polar Vortex):

Fluffy snows are expected today and tonight, producing accumulations with very little water. Commonly, the percentage of water to snow is called the "snow ratio". An old rule of thumb was that for every 10 inches of snow, there would be 1 inch of water (10:1).