Avalanche Forecast

A series of fast moving storms moves through the region with continued precipitation and moderate to strong winds. The highest snowfall amounts and wind are forecast for the storm arriving Friday thru Saturday.

Tuesday night: Cloudy with isolated flurries, trace to 6cm new snow, moderate southwest ridgetop wind gusting strong, alpine low -1 C, freezing level 1100 m.

Wednesday: Cloudy increasing precipitation in the afternoon and overnight, 8-15 cm new snow (or rain), moderate southwest ridgetop wind, alpine high 1 C, freezing level 1400 m.

Thursday: Cloudy with scattered flurries, 5-10 cm, moderate northwest wind, alpine high 2 C & low-2C, freezing level 1400 m.

Friday: Heavy Snow, 20-35cm new snow, moderate south winds gusting strong, alpine high 1 C & low-2C, freezing level 1400 m.

Limited observations from Tuesday have been reported, however natural and explosive controlled avalanches are expected with the recent strong to extreme southwesterly winds and new snow. Avalanche activity will taper with the lull between storms as precipitation lightens and winds ease overnight Tuesday into Wednesday. However, be on guard for changing conditions as the next storm arrives on Wednesday afternoon with fresh snow and winds.

On Friday and Saturday, we received reports of natural and skier controlled loose dry size 1 and storm slabs size 1-1.5. See photos of some touchy remote triggered slabs during the storm Friday in this great MIN from Pump Peak. Continued snowfall (20-40cm) with moderate to strong southwesterly winds on Monday night and Tuesday will likely result in deteriorating avalanche conditions and a natural avalanche cycle.  

Have you been out and about in the mountains? If so please submit your observations to the Mountain Information Network (MIN). It doesn't have to be technical - photos are especially helpful! Thank you so much for all the great MINs submitted so far!

20-50 cm fell with moderate to strong Southwest on the North Shore mountains by end of the day Tuesday bringing storm totals the past week to 40-80 cm. This recent snow sits on a thin melt freeze crust from Monday afternoon, a deeper thin melt freeze crust on solar aspects, and possibly over a layer of weak surface hoar crystals in wind sheltered areas. This MIN from Saturday includes photos of the surface hoar before it was buried.

A layer of weak crystals sitting on a 20 cm thick crust is now covered by 40-70 cm of snow. We have had our eyes on it since it became buried last week. We haven't seen any avalanches on this layer since Saturday and snowpack tests since Sunday have shown no results at this interface.

Below treeline snowfall amounts are approaching threshold for avalanches to occur.

We have very little data and a lot of uncertainty around alpine conditions in the region. If you go out in the mountains, please let us know what you see via the Mountain Information Network (MIN). 

• Watch for fresh storm slabs building throughout the day.
• As the storm slab problem gets trickier, the easy solution is to choose more conservative terrain.
• Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.