We lost our snowpack practically overnight — well at least in the last 48 hrs. How did this happen? Warm moist air over the colder snow and ground created foggy conditions over the last 2 days. Advection (horizontal transfer of air by wind) of warm moist air over a snow pack is the most efficient way to melt the snow. Why? When the moist air condenses on the snow it releases heat, a process known as the latent heat of condensation. This heat is imparted to the snowpack and helps to increase the melt rate considerably — even more so than a rain on snow event. With an active weather pattern continuing however, we can still keep our fingers crossed for a white Christmas.