Watch out for wind slabs they're likely reactive to human triggers at upper elevations. Choose conservative terrain and watch for signs of instability such as whumphing, cracking and recent avalanches.
Strong southwest wind is forecast for the rest of the week along with a bit of new snow. Use caution near ridges and avoid leeward slopes, particularly where you find stiff wind affected snow. Loose-dry sluffing from steep terrain features.
30-50 cm of snow currently sits above a buried crust from early December. Sugary, facets above and/or below the crust may weaken the bond and the persistent slab may become reactive, especially to human triggers.
Friday: Snow amounts 5cm with alpine temperatures near -7. Ridgetop wind strong-extreme from the southwest and freezing levels valley bottom.
Saturday: Snow 5-10 cm with alpine temperatures near -7. Strong-extreme wind from the West and freezing levels 1000-1500 m.
Sunday: Snow amounts 10-20 cm. Alpine temperatures -1 and freezing levels 2000 m. Extreme 65-105Km/hr wind from the southwest.
No new reports on Thursday. Avalanche control using explosives in the Lizard range produced several slabs up to size 2 in alpine terrain and a size 1.5 in treeline terrain. This may indicate that slabs may be sensitive to human triggers on Friday.
Please consider sharing your observations on the Mountain Information Network. Thank you to those that have already submitted this winter.
Up to 20 cm of new snow and strong to extreme southwest wind have likely formed reactive wind slabs at treeline and in the alpine. The recent snow brings 30-50 cm above the early December crust which exists in the snowpack up to 2000 m. Use caution if you find cohesive snow above the crust, particularly if there are weak, sugary faceted grains immediately above or below the crust. With slab cohesion adding stress and load on that interface we may see this persistent slab avalanche problem come to life.
The snowpack depth varies substantially in the region and has been described as thin, wind-hammered, variable, and tapering rapidly at lower elevations. The average snowpack depth at treeline is approximately 100 cm.
The middle of the snowpack has been reported as being well-consolidated and may host another hard melt-freeze crust.
The base of the snowpack consists of a hard melt-freeze crust from early-November that may have faceted grains around it. There has not been recent avalanche activity on this layer but it remains on our radar. The most likely spot to trigger it would be on thin and rocky slopes.
