It depends
I know from reading what John has wrote in the past, that it would depend on the air temp and other variables as to how much would pile up. The colder it is the smaller the flakes are and the less that it accumulates. As a general rule, I think if you use about 10" of snow per 1" of rain, you will be close. So, you would have about 400" of snow, which would probably settle to about 60" or so, just a guess.