2.2.8 Snowpack depth and SWE
Does a deeper snowpack always produce more water? The snow depth on the left side of the graphic is 10 in (25 cm), a dense snowpack with an SLR of 2:1 that would melt down to a SWE of 5 in (13 cm). In contrast, the snow depth on the right is 20 in (51 cm), the SLR for that low-density, fluffy snowpack is 20:1, and the SWE is only 1 in (2.5 cm). The snowpack on the left will produce five times as much snowmelt as the one on the right, even though it's only half as deep.
This map shows how average snowpack density values vary across CONUS. The lower SLR values (the wetter, denser snow) correspond to more maritime climates, while the higher values are characteristic of colder and/or higher elevation snowfalls in the interior of the country.