Avalanche Forecast

Moderate -

On Tuesday, sunny conditions are expected with light alpine wind from the southwest in the morning becoming moderate to strong in the afternoon. Freezing levels are forecast to reach around 2800 m with a temperature inversion keeping the valleys colder than the alpine. A layer of valley fog may also develop. On Wednesday, mostly cloudy conditions are expected with light rain beginning in the afternoon. Alpine wind is forecast to be moderate to strong from the southwest and freezing levels are expected to remain at around 2500 m. Light rain is forecast to continue Wednesday night and Thursday. 3-6 mm of precipitation is currently forecast between Wednesday afternoon and Thursday evening. Freezing levels are forecast to drop to around 2000 m on Thursday.

On Sunday, a couple natural size 1.5-2.5 wind slabs were observed. Two remotely triggered size 2-2.5 storm slab released from up to 30 m away. A ski cut on a northeast aspect at 1300 m elevation triggered a size 1.5 deep persistent slab which failed on an old layer near the bottom of the snowpack. Explosives triggered numerous storm slabs up to size 2.5 as well as two deep persistent slabs up to size 3.5 which released down 200 cm, most likely on the November crust. On Friday, explosives triggered two deep persistent slab avalanches which released down 200 cm. On Tuesday, storm slabs overlying a weak layer are expected to remain reactive to human triggering. It also appears that the November crust layer is beginning to wake up with the warm conditions and deep persistent slab avalanches are becoming a serious concern. Extra caution is recommended during the heat of the afternoon, especially on sun exposed slopes. This will become increasingly important through the week as freezing levels remain very high. We have entered the first period of substantial warming following months of sustained cold conditions and lingering weaknesses in the snowpack are once again becoming reactive.

The storm snow from Thursday and Friday is settling quickly due to the recent mild temperatures. The snow surface is expected to have undergoing some melting on Monday afternoon on sun exposed slopes. Recent strong winds from the south and west had redistributed the recent storm snow in exposed terrain forming touchy wind slabs. The early February interface is now down 60-80 cm and includes sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. A persistent weakness buried mid January is now down 80-150 cm and the November crust is down around 200 cm. These deep persistent weaknesses appear to be waking up with the warmer temperatures and several avalanches have recently released up to 2 m deep.