As a commercial pilot nearly all my adult life, one of the first paying jobs I had flying aircraft here in the western U.S. was for a hydrologist in the back country of the northern Rocky Mountains measuring the snowpack. We used a small Super Cub aircraft on skis (like this:
http://www.super-cub-...-cub-kits-on-skis.jpg )and made numerous flights throughout the winter. By we, I refer to the licensed hydrologist that always accompanied me.
I found from him (sometimes a her) that the water content of snow is highly variable. The wind velocity and temperature during the snowfall is most the controlling of factors. Additionally, the source of the moisture forming the snow has a lot of influence. The snow that falls on the lee (eastern) side of the Rockies tends to be "dryer" than say snow falling on the windward (west) side of the Cascades or other Pacific coastal mountains. The snow content can easily vary from around .04 to .10 water to snow ratio.
Here's a site that may be of interest (applicable to the U.S. of course):
http://www.nohrsc.nws.gov/index.html
By the way, most snow pack measurements today are done remotely through radio or satellite transmitted data... but it was realy fun while it lasted and besides, they were willing to pay me for it...