Avalanche Forecast

A building ridge will bring cool and clear conditions for the next few days. 

WEDNESDAY NIGHT: Partly cloudy, light southwest wind, alpine temperatures drop to -10 C.

THURSDAY: Mix of sun and cloud, light wind, high temperatures around -5 C.

FRIDAY: Mostly sunny, light wind, high temperatures around -7 C.

SATURDAY: Mostly sunny, moderate west wind, high temperatures around -10 C.

As the weather clears we are uncertain about how quickly the recent snow will gain strength and bond to old interfaces. It likely sits atop a weak layer of surface hoar in wind-sheltered areas at treeline and at upper below treeline elevations (above the extent of the rain crust). Wind slabs likely linger in higher wind-affected terrain.

With little in terms of field observations, a cautious and conservative approach to terrain is needed. Be aware of these new avalanche problems by looking for signs of instability like shooting cracks and whumpfs. Furthermore, an avalanche triggered in the upper snowpack could cause a larger deep persistent slab avalanche.

Our eyes and ears in the mountains are limited this winter due to fewer professional observations. If you go out in the mountains, please share your observations on the Mountain Information Network (MIN).

A warm storm earlier this week has likely reshaped the snowpack. Heavy rain was reported up to 1500 m, so lower elevations will now have a thick surface crust. 15-40 cm of snow fell at higher elevations, with the largest accumulations around Valemount and Blue River. In the alpine this snow has formed thick wind slabs, which should generally be strengthening quickly. Intermediate elevations (below alpine terrain and above the rain line) could have highly variable conditions and perhaps a dangerous problem developing. The most concerning thing at this elevation is if a slab of dry snow has formed above widespread surface hoar layer (or above sun crusts). Carefully assess open slopes at intermediate elevations if you see recent accumulations of dry snow.

The lower snowpack is characterized by a couple of crusts, the most notable of which is sitting near the base of the snowpack, surrounded by a weak layer of sugary facets. It is most likely to be reactive to human triggers on south facing slopes and in shallow, rocky areas in the alpine.

• Choose conservative terrain and watch for clues of instability.
• Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Be aware of the potential for large avalanches due to the presence of a deep persistent slab.