Avalanche Forecast

Moderate -

THURSDAY NIGHT: Cloudy with isolated flurries and a trace of new snow. Light to moderate southwest winds increasing into the morning.

FRIDAY: Cloudy with scattered flurries and a trace to 5 cm of new snow, increasing a bit overnight. Light to moderate southwest winds, becoming strong at ridgetop. Alpine high temperatures around -7 with freezing levels rising to 1000 m.

SATURDAY: Cloudy with continuing flurries bringing about 5 cm of new snow and new snow totals to 10-15 cm. Flurries continuing overnight. Moderate southwest winds, becoming strong at ridgetop and increasing overnight. Alpine high temperatures around -5 with freezing levels rising to 1300 m.

SUNDAY: Cloudy with continuing flurries bringing 5-15 cm of new snow with 3-day snow totals reaching 20-40 cm. Light to moderate southwest winds, becoming strong at ridgetop. Alpine high temperatures around -4 with freezing levels rising to 1600 metres.

A skier triggered avalanche was reported in the Golden area on Wednesday. Check out the MIN report HERE. The 50 cm failure plane depth matches up with the persistent weak layers discussed in our snowpack summary. The report also suggests that in some areas more recent wind slabs may be quite reactive.

On Monday, a size 1.5 skier triggered persistent slab avalanche on a NE aspect in the alpine was reported near the Gorman area. It was reported to have failed on a crust.

On Sunday, a size 2.5 explosive triggered persistent slab avalanche was reported on a north aspect near Golden. Another reminder that on the wrong piece of terrain, very large avalanches are still possible to trigger.

A skiff of new snow has buried a new layer of surface hoar in many parts of the region. This will be a key interface to watch as new snow piles up over the weekend.

Also at the surface, winds blowing from a variety of directions last week formed wind slabs in lee features at treeline and above.

There are currently several critical layers of concern. The early December surface hoar is down 30 to 80 cm. It has recently been sensitive to remote triggering which is well illustrated in this MIN post from the Golden area.

Below, or near the surface hoar you may encounter a crust. This crust has been observed as high as 2400 m. in the south of the region and 1800 m. in the north.  

The lower snowpack is characterized by more crusts, the most notable is a rain crust from early November that is 50 to 130 cm deep. This crust 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 in steep, shallow, rocky areas with a thin to thick snowpack.

• Uncertainty is best managed through conservative terrain choices at this time.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
• Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
• Remote triggering is a concern, watch out for adjacent and overhead slopes.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.