Avalanche Forecast

FRIDAY Night: Cloudy with snowfall, accumulation of 5 to 10 cm. Winds moderate southwest gusting strong. Alpine temperature around -12 C with freezing level dropping to valley bottom as cold front passes.

SATURDAY: Cloudy with sunny periods and isolated flurries. Trace precipitation up to 5cm. Winds light to moderate West / Northwest. Alpine high temperature -10 C with freezing level 900 m.

SUNDAY:Mostly cloudy with isolated flurries, trace accumulation. Winds light to moderate west. Alpine high temperature -11 C and lows near -15 C with freezing levels at valley bottom.

MONDAY: Cloudy with snow flurries, accumulation 5 -10 cm. Alpine high temperatures -10 and lows of -14 C. Freezing Level 800m.

A few small to large (size 1 to 2) wind slabs and a few storm slabs were triggered naturally and by humans on Wednesday and Thursday. On Thursday numerous small and a couple large avalanches on the surface hoar layer were reactive to skier traffic on steep and unsupported or convex features. On Wednesday they generally occurred on northerly aspects between 2000 and 2300 m and were 20 to 50 cm thick.  

Wind slabs were most reactive in the Northeast portion of the region and were from recent wind loading while persistent slabs released in the south of the region on the surface hoar layer described in the snowpack summary.

Friday night's 5-10cm of new snow will fall with moderate to strong winds and a cooling trend. This will bring total snowfall overlying the widespread layer of surface hoar that was reported to be between 5 and 15 mm in size to 20-45cm.  

Recent warm temperatures have built slab like properties in this snow, particularly at mid and low elevations, making the persistent layer more reactive as evidenced in the avalanche discussion. There is variability in the reactivity and distribution of this layer, particularly in the northern half of the region. In the southern half, this layer exists on all aspects and elevations except for steep, sun-exposed aspects where it was melted by sun and formed a melt-freeze crust. So far, the overlying snow has been reactive to human activity where the wind has redistributed it, forming a slab. This has been most common around treeline and alpine elevations in the south of the region. 

The mid and lower snowpack is generally well-settled and strong.

• Stick to simple terrain or small features with limited consequence.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Be aware of the potential for large avalanches due to the presence of buried surface hoar.