Avalanche Forecast

Fair - Intensity of incoming weather is uncertain on Saturday

Thursday:  Continued moist precipitation.  15 -20mm water expected.  Freezing Level: 1800m, lowering throughout the day.  Wind: Moderate to Strong, Southwest.Friday:  Occasional light showers/flurries. 5mm water expected.  Freezing Level 1500m.  Wind Moderate, SW.Saturday:  Another pulse of moisture makes its way inland.  15mm water expected.  Freezing level tops out around 1800m in the afternoon lowering to 1000m Saturday night.  Wind: Light, SW

A widespread natural avalanche cycle to size 2.5 was reported from the Duffey on Wednesday.  The Coquihalla reports several wet naturals from size 1 - 2.5 running to the top of the runouts.  There was a report of a size 2 skier triggered slab avalanche on a steep southwest aspect in the Steep Creek area (Duffey Lake) on March 8th.  Granted, it's a few days old but it highlights the lingering potential for triggering large slab avalanches.

The storm has delivered around 30 cm as of Wednesday afternoon and another 10 - 20 is expected overnight.  This new snow is bonding poorly to the previous snow surface, which includes faceted snow, surface hoar, and/or a crust, but is most concerning where surface hoar is sitting on a crust on previously sun-exposed sheltered treeline slopes. Around a metre below the snow surface is a layer surface hoar buried on February 20th. Although this layer has a history of producing large avalanches, triggering this layer has now become difficult, and would most likely require a very large trigger on a steep, unsupported slope. Below this interface, the snowpack is strong and well settled.