19 Jan 2012

Sublimation of the snow at ridge tops is common as it moves up into the atmosphere driven by the wind.
Sublimation is the process of transition of a substance from the solid phase to the gas phase without passing through an intermediate liquid phase. Sublimation is an endothermic phase transition that occurs at temperatures and pressures below a substance's triple point in its phase diagram.
With the cold temperatures we have been having, snow making is pumping out the snow !! or is it? Yesterday morning many of the guns on Blackcomb were turned off because of sublimation. The very cold temperature's and humidity affected the snow production.  In the morning it appeared that 40 %-60% of the snow coming out of the guns was sublimating. There were great turns to be had on the man made snow yesterday!!!

Snow gun at full production on Cruiser run at the end of the day on Wednesday.
The snow is rising into the atmosphere and sublimating.
At 2280 meters the temperature at 06:00 was -14.5, winds were 25-35 KPH from the south. At 1550 there is a trace of new snow, the temperature was -18.5, relative humidity was 88% and the barometer is on a slight decline. In the valley it is -18.

For an up to date Avalanche Advisory click here: Avalanche Advisory

Check out this video of extended column test on Dec 12, 2011 surface hoar down 40 cm at Panorama Ski Resort.

For more information on how much snow is lost in sublimation click here: Sublimation in Snow