Avalanche Forecast

Sunday night: Mostly cloudy, scattered flurries with 2-5 cm of snow, light southwest winds, alpine temperature -10 C.

Monday: Decreasing cloud, light northwest winds, alpine high temperature -9 C. 

Tuesday: Increasing cloud, light southwest winds, alpine high temperature -10 C.

Wednesday: Cloudy, 5-10 cm of snow, light southwest winds, gusting at ridge-top, alpine high temperature -9 C.  

During the storm, numerous size 2-3.5 avalanches released naturally in the storm snow. These avalanches primarily occurred on leeward aspects and mainly at treeline and alpine elevations. Reports also indicate that cornices may be reaching their breaking point and may act as triggers for these avalanches. Below tree line, large wet loose avalanches were releasing naturally on Friday and into Saturday.

Over the last week, there have been two notable natural avalanches reported in the south of the region. These were large (size 2.5) avalanches breaking 200 cm deep on both northeast and northwest slopes above 2300 m. Although unlikely, these avalanches are a reminder that a deeper instability may linger in isolated areas where the snowpack transitions from thick to thin. Easier-to-trigger wind slab avalanches or cornice fall may have the potential to step-down to this layer. 

There have been substantial changes to the snowpack over the past few days from wind, snow, and warming. Snow accumulation varied widely across the region, with higher amounts falling in the eastern half. Anywhere from 30-70+ cm of storm snow has accumulated at upper elevations (generally above 1900 m). Strong winds originating from the southwest and shifting to the northwest have created a tricky loading pattern above tree line and have elevated concern for cornice triggers. These winds drifted the snow into deeper, stiffer slabs on leeward terrain features that may be possible to human trigger. During a warming event Saturday night, rain saturated snow surfaces up to around 1900 m that have since refrozen with cooling temperatures.

The mid and lower snowpack is generally well settled and strong. Although isolated, there are two deeper layers that may still persist. A layer surface hoar currently buried 100 to 180 cm deep from late December and a facet/crust layer from November near the ground. 

• Remember that the snowpack will be significantly different at higher elevations than lower down.
• Stay off recently wind loaded slopes until they have had a chance to stabilize.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.