Liquid water content is defined as the amount of water within the snow that is in the liquid phase. This parameter is synonymous with the free-water content of a snow sample. Liquid water in snow originates from either melt, rain, or a combination of the two. Measurements of liquid water content or wetness are expressed as either a volume (LWC_V) or mass (LWC_m) fraction. Both can be reported as a percent (%), which usually requires a separate measurement of density (Fierz et al., 2009)

http://costsnow.fmi.fi/index.php?page=A1