To be awesome on the snow, to gain accreditation for almost super nautral feats on snow or ice. The equivalent of street cred but in cold climates. Snow cred is given out to extreme sportsmen and women who perform outrageous tricks and skills in: Snowboarding, Ice biking, Snowmobiling... etc. It is acknowledgement of the achievements and strides in snow sports.
Man that was some sick sick air you got there, gotta give you snow cred for that.