Avalanche Forecast

Moderate - The weather pattern is stable

As the upper ridge sets up, we move into a period of cooling, drying and fairly light, northerly winds. SUNDAY: Mix of sun and cloud/ alpine temperatures near -8/ generally light winds from the northeast/ freezing level 900 mMONDAY: Cloudy/ alpine temperatures near -10/ ridgetop winds light from the northeast/ freezing levels valley bottomTUESDAY: Mix of sun and cloud/ alpine temperatures -12/ ridgetop winds light from the northeast/ freezing levels valley bottom.

On Saturday, a natural size 3 slab avalanche was seen on Mt. Begbie  (ENE aspect above 2000 m). We suspect that it might have been triggered from rockfall or a cornice above the slope and propagated wide. This avalanche may have failed on the basal crust, which we suspect it may need a large trigger, but if triggered will be very large and destructive.On Friday, two glide slab avalanche releases were reported up to size 2 from north through east aspects at 1600 m and 1900 m. These released to ground in specific geothermal terrain features. On Thursday, a deep persistent slab avalanche was triggered by explosives. This avalanche was a size 2.5 from a northeast aspect in an upper alpine bowl. The avalanche initiated from a shallow, rocky spot with good propagation and failed on the buried crust at the base of the snowpack. This avalanche character is very similar to the human triggered size 3 mentioned below.Last Saturday, a human triggered size 3 avalanche was reported in the region. This avalanche likely ran on the October crust, as it was reported as a full depth avalanche. Two reports on this avalanche can be found on the Mountain Information Network.

40-80 cm of recent snow sits on two layers of feathery surface hoar that are approximately buried 15 cm apart. One or both of these may be associated with a crust on south aspects. The surface hoar is mostly found at treeline, but it may be found in sheltered alpine areas. Snowpack test results on these layers are showing a variety of planar results which indicate that this interface may be susceptible to human triggers.At the base of the snowpack is a crust that formed near the end of October. This crust is associated with sugary weak faceted crystals and has shown some reactivity in the South Columbia region. Suspect slopes and terrain are open bowls that host a rocky thin to thick snowpack in the alpine or upper treeline. Snowpack depths taper quickly with elevation, many areas have over 200 cm in the alpine, between 100-170 cm at treeline, and 10-100 cm below treeline.Check out the FORECASTER BLOG as it will express our uncertainties with the current snowpack in this region.