North Columbia

As winds increase from the south, hazard will worsen throughout the day. Be especially cautious anywhere higher snowfall amounts (near 25 cm) are found or wind is actively transporting snow. Remember, fresh wind slabs will be touchy anywhere they sit on slippery surface hoar.

Active weather will bring light snow to the region with increasing winds and warmer temperatures. Stormier conditions, warmer temperatures and heavier snow is forecast for the southern zones.

Friday night: Cloudy clear periods, light southwest ridge wind and alpine low temperature around -10C.

Saturday: Cloudy with sun breaks and isolated flurries, trace to 5 cm new snow, light to moderate southerly wind and alpine high temperatures around -8C. An additional 2-10 cm is forecast late afternoon and overnight. Freezing level 800 m.   

Sunday: Cloudy with scattered flurries, 5-20 cm new snow, light to moderate southeast wind and alpine high temperatures around -7C. Freezing level 700-1000 m.  

Monday: Southern regions: heavy snow, 10-25 cm new snow, light southwest wind gusting strong, alpine high temperatures near -3C and freezing levels rising to 900 m.  

Northern regions: a mix of sun and clouds with isolated flurries and trace new snow, light to moderate southeast wind, alpine high temperatures around -6C and freezing levels valley bottom.

There were no new avalanche observations from from Friday, although data sources are limited at the time of publishing. On Thursday there were isolated reports of newly formed small (size 1) storm and wind slabs releasing with skier traffic as a result of recent flurries and wind. Loose dry avalanches (sluffs) to size 1 of recent low density snow overlying a slippery surface hoar layer in steep terrain has been more widely reported, particularly below tree line. 

We're continuing to track a layer of surface hoar from early January, the most recent activity reported on this layer was January 17 from Clemina Creek documenting cracking and propagation in sheltered treeline and below treeline areas on surface hoar buried 40-50 cm deep. Although it has followed a trend toward being unreactive, this layer continues to sporadically produce easier, more sudden snowpack test results that make it worthy of continued monitoring.

15-25 cm of recent low density snow has covered a widespread layer of weak surface hoar. The highest snowfall amounts were reported in the south Monashees while in the far north there are regions with even less recent new snow, as reported in this MIN from Clemina. This surface hoar grew up to size 15 mm on a variety of surfaces that include heavily wind affected surfaces in exposed terrain, a thin sun crust on steep solar as well as more variable wind affected and faceted snow in sheltered spots. Below 1600 m, 20-30 cm of snow is settling above a decomposing melt freeze crust. 

Observers continue to find a deeper preserved layer of surface hoar down 40-80 cm in sheltered, open slopes at and below treeline. Recent snowpack tests have produced sudden results on this layer, other tests have found it unreactive, as such it continues to warrant slope-specific assessment. 

Deeper in the snowpack, a couple of older persistent weak layers may still be identifiable from late and early December, consisting of surface hoar and a crust with faceted snow and buried anywhere from 100-200 cm deep. Prolonged periods of inactivity and unreactive snowpack test results suggest that these layers have trended towards dormancy. 

• Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.