Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain

SATURDAY: Mix of sun, cloud and isolated flurries / Light to moderate southwest wind / Alpine temperature -9 / Freezing level 1100m SUNDAY: Flurries, accumulation10-15cm / Moderate to strong southwest wind / Alpine temperature -10 / Freezing level 900m MONDAY: Scattered flurries, accumulation 5cm / Light west wind / Alpine temperature -10 / Freezing level 800m

Avalanche activity on Thursday included wind slabs, storm slabs and persistent slabs. Several wind slabs and storm slabs were reported to be running to size 2.5 on all aspects in the alpine and tree line. These were mostly natural triggers with a few human triggered to size 1.5. Additionally, there were a few persistent slab avalanches remotely triggered to size 2 on northerly aspects at tree line.On Wednesday wind slab avalanches to size 1.5 were human triggered on northwest, north and northeast facing features between 2000 m and 2150 m. A size 2.0 persistent slab avalanche was human triggered on a northeast facing feature at 2200 m, this slab failed on the early January weak layer. There was also a natural size 2.5 glide crack failure on a southeast/east facing feature at 1600 m. Bear in mind that this activity occurred before the storm.

The current snowpack is complex, we now have three active weak layers that we are monitoring. 20-40cm of storm snow now sits on a newly formed crust and/or surface hoar interface. Prior to the storm the crust was reportedly widespread; high elevation north is likely one of the few crust-free zones. The now buried surface hoar is 5 to 20mm in size and was reportedly present at all elevations before the storm. Looking deeper, a persistent weak layer known as the early January interface is 50 to 90 cm below the surface. It is composed of surface hoar on sheltered slopes as well as sun crust on steep solar aspects and was present to at least 2100 m, possibly higher. Recent snowpack tests have shown sudden results with moderate loads. Additionally, yet another persistent weak layer buried mid-December consisting of a facet/surface hoar/crust combination, is buried 80 to 150 cm deep. It is most problematic at and below tree line. This interface is not thought to be present in the alpine. A rain crust buried in November is 150 to 200cm deep and is thought to have gone dormant for the time being.