630 am update: New snow and wind are forming reactive storm slabs. Stick to simple, low angle, wind sheltered terrain free from overhead hazard.
New snow and wind are forming fresh storm slabs. The deepest and touchiest deposits are likely to be found in lee terrain features at wind affected elevations.
Low density snow that hasn't formed a slab will be prone to loose dry sluffing in steep terrain at all elevations.
A variety of buried weak layers will be stressed by the sudden hit of new snow load. Very large, destructive avalanches are possible.
Storm and wind slabs have been reactive recently. In the past few days, we've had reports of naturals size 2-3 and skier triggered storm slabs up to size 2, some remotely triggered from a distance.
Looking forward, we are expecting a widespread natural cycle with potential to step down to buried weak layers, possibly resulting in very large avalanches.
30-60 cm is forecast to fall by the end of Thursday. The new snow is likely being wind loaded into lee terrain features at wind-exposed elevations, while falling light and fluffy in sheltered areas.
A layer of small surface hoar or facets is now buried over 80 cm deep. A facet/crust layer formed in late January exists around 150 cm deep. Large avalanches were suspected to have run on this layer over a week ago.
The lower snowpack is generally well consolidated but as you move further inland where the snowpack is thinner, basal instabilities linger.
The total height of snow in the alpine varies between 450 cm near the coast and 250 cm further inland.
A juicy northwest flow will deliver the bulk of the snowfall and strongest wind from this system overnight Wednesday. On Thursday, the unstable, convective airmass following in the wake of the cold front will bring locally variable snowfall through the day, tapering overnight and clearing on Friday.
Wednesday night
20-40 cm of new snow. Strong southwest wind peaking in the early evening. Alpine temperatures around -8ºC.
Thursday
5-20 cm of new snow. Moderate southwest wind. Alpine high -10 ºC.
Friday
A mix of sun and cloud. Light to moderate westerly wind. Alpine high -10 ºC.
Saturday
Mostly sunny. Light to moderate easterly wind. Alpine high -8 ºC.
More details can be found in the Mountain Weather Forecast.
