South Columbia

The snowpack will likely need more time to adjust to the recent load of storm snow. Uncertainty exists around the buried, weak surface hoar layer. We suspect the potential for human triggered avalanches remain high.

Moderate - Due to the number of field observations

The weather trend will start to stabilize as a high pressure system sets up through the forecast period. THURSDAY: Mostly cloudy with new snow 5-10 cm/ alpine temperatures near -4/ generally light winds from the SSW/ freezing level 1300mFRIDAY: Cloudy with sunny periods with a trace of new snow/ alpine temperatures near -9/ ridgetop winds light from the West/ freezing levels 900 mSATURDAY: Mix of sun and cloud/ alpine temperatures -9/ ridgetop winds light from the southwest/ Freezing levels near 800 m

Avalanche activity spiked with the recent storm. This initiated a natural avalanche cycle up to size 2 on most aspects. Reports from the field also noted remote (from afar) human triggered avalanches up to size 1.5. By using explosives, commercial operations were able to trigger larger more destructive avalanches up to size 2.5, mostly on northerly aspects at upper elevations.Natural avalanche activity may taper off as the weather pattern becomes more stable. As the snowpack adjusts to this recent load, it's likely that human triggered avalanches will be the name of the game.Last Saturday (before the storm), 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.

The storm that arrived earlier this week distributed 40-80 cm of new snow by Wednesday morning. The higher accumulations were found in Monashee mountains. This snow sits on a weak layer of surface hoar (feathery crystals) and sun crust on steep south facing slopes. The surface hoar is widespread at treeline and below, but it may be found in sheltered alpine areas.At the base of the snowpack is a crust that formed near the end of October. This crust has shown limited reactivity in the South Columbia region, but with recent additional snow, high winds and warm temperatures, this layer could come into play.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.