Avalanche Forecast

A weak weather system will bring light snow, moderate west/southwest winds and cool temps for the weekend ahead of a building high pressure system for Monday / Tuesday.

Saturday night: Cloudy with clear periods and isolated flurries. Alpine low temperatures near -9C and freezing levels valley bottom. Ridgetop wind light to moderate from the west / northwest.

Sunday: A mix of sun and clouds with isolated flurries. Alpine high temperatures near -8C and freezing levels valley bottom. Ridgetop wind light and variable gusting moderate.

Monday: Mix of sun and cloud. Alpine high temperatures near -9C and freezing levels valley bottom. Ridgetop wind light and variable west.

Tuesday: Mix of sun and cloud. Alpine high temperatures near -12 and freezing levels valley bottom. Ridgetop wind light and variable.

From Saturday there were reports of several intentionally triggered small (size 1) soft wind slab avalanches and a small (size 1) explosive triggered avalanche from a cross-loaded alpine feature at treeline. Sluffing of loose dry snow is building mass to size 1 from steep wind sheltered terrain. A nearby neighbour reported a large avalanche (size 2) that imitated as a windslab or cornice failure and stepped down to the December crust on Friday. Another neighbour reported a large (size 2) windslab from a west aspect from cross-loading from recent variable east winds.  

On Thursday there were reports of small (size 1) and large (size 2) windslabs from explosive control within the region and explosive controlled very large (size 3) avalanches and cornice triggered very large (size 2.5-3) avalanches from adjacent regions.  

During the height of the cycle on Wednesday there were numerous storm slabs up to size 1.5 that were triggered with explosives. This MIN from Tunnel creek on Dec 24th also reports numerous large avalanches on cross loaded features at treeline. On Tuesday, a widespread natural avalanche cycle up to size 3 was reported from the lizard range with many avalanches reported from northerly aspects. 

Please consider sharing your observations on the Mountain Information Network. Thank you to those that have already submitted this winter!

30-60 cm of recent snow blanketed the region by Tuesday morning and has been blown by moderate to strong winds in exposed treeline and above since then. Moderate to strong west and southwestern winds created significant ridgetop snow re-distribution onto lee slopes. Wind slabs will likely remain reactive to human triggers, and are the most reactive during periods of moderate to strong winds. Cornice development may be found along ridgecrests and deep windslabs on lee slopes. 

Recent snow fell on a variety of old surfaces including a buried melt-freeze crust reported below 1700m and surface hoar reported around treeline. This Min from Mt. Fernie on Dec 26th found 5-15cm of low density snow above this recent crust while this Min near Tunnel Creek found it down 20cm.  

Buried 60-130cm one can find a variety of weak layers from early December. This persistent weak layer, with facetted crystals and surface hoar crystals above and/or below it is reaching a tipping point. Deeper in the snowpack are two hard melt-freeze crusts that formed in November that may have some weak crystals around them. This potential avalanche problem is dormant at this time, however; it remains on our radar.

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Approach lee and cross-loaded slopes with caution.
• Shooting cracks, whumphs and recent avalanches are strong indicators of an unstable snowpack.
• Minimize your exposure time below cornices.
• Don't let the desire for deep powder pull you into high consequence terrain.