I live in Colorado and we get quite a bit of snow.  I was concerned about how the artificial turf would hold up with snow and the drainage with the spring melt.  I found a company online named Global Syn Turf that explained the following.  Artificial turf can easily withstand the weight of the snow pack in winter.  The synthetic grass also have very sufficient drainage for when the snow melts in the spring.  This information really put my mind at ease and had the Colorado supplier for Global Syn Turf install our turf last week.  A+ rating for Global Syn Turf's synthetic grass.