Avalanche Forecast

Fair - Due to the number and quality of field observations

Freezing levels will drop to valley bottom overnight as a cold front moves across the province.  A ridge of high pressure will build over the coast on Wednesday resulting in clear skies and light SW winds in the interior.  A weak front will move across the province on Friday bringing isolated flurries.

As the temperature drops I expect that avalanche activity will slow down.   The recent snow, rain, and wind were a great test of buried persistent weaknesses in the snowpack and resulted in a widespread avalanche cycle.   The mid-January surface hoar layer has been responsible for the majority of the recent avalanche activity in the region, producing numerous avalanches up to size 3.

I suspect that freezing levels rose to about 2000m during the recent warm spell and that rain saturated the upper snowpack. At higher elevations sustained moderate to strong winds have formed widespread windslabs. Snow moist enough to make snowballs with has been found near the surface below 2200m and as deep as 80cm at lower elevations.  As the freezing level drops back a widespread melt freeze crust will form.  I suspect that at lower elevations warm moist snow may have destroyed the mid-January surface hoar layer.  Where it still exists it can be found down between 40 and 80 cm.  The midpack is broken by the mid-December surface hoar layer that is now 80 to 140cm below the surface.