snowpack 
noun
A mass of lying snow that is compressed and hardened by its own weight: the snowpack is melting a decent depth of snowpack...
- Spring came and the snowpack melted like an ice cube on hot asphalt, instead of compacting and forming the vast fields of perfect-corn snow we expected.
- The next day, the bright Arizona sunshine was back in action, melting the snowpack in the Huachuca Mountains.
- He digs snow pits to look for weak layers in the snowpack, and cuts sections of the slope with his skis to see if he can dislodge unstable pockets.