Northwest flow brings cold, dry snow. If you see more than 30 cm of new snow in your local area, treat avalanche danger as HIGH in the alpine. In some areas, slabs may fail down to a recently buried crust, resulting in larger than expected avalanches.
Where it hasn't formed a slab, new snow may be prone to sluffing in steep terrain. Sluff can be fun as long as it's managed appropriately in order to avoid getting pushed off your feet or into terrain traps.
New snow and wind are forming fresh and reactive storm slabs. There is potential for slabs to fail down to a recently buried crust, propagate widely and run surprisingly far.
A slew of MINs from the Mt Cain area over the weekend and Monday reported several rider triggered storm/wind slab avalanches up to size 2. With new snow piling on top, this type of activity can be expected to continue, but with potential for larger avalanches running naturally.
If you head into the backcountry please consider sharing your observations on the Mountain Information Network!
New snow is likely being wind loaded into lee terrain features at wind-exposed elevations, while falling soft, cold and dry in sheltered areas.
A thick, widespread crust formed in mid February sits 20-40 cm deep. Near Mt Cain, a poor bond exists between this crust and the overlying snow. Elsewhere it seems to be bonding well. You can check in your local area by performing a simple hand shear test on an isolated block.
The mid and lower snowpack is well consolidated, containing a series of well-bonded crusts.
A northwest flow will deliver the bulk of the snowfall and strongest wind from this system overnight Wednesday. The unstable, convective airmass following in the wake of the cold front will bring locally variable snowfall. Mount Cain is looking promising as a hot spot for Thursday.
Wednesday night
5-15 cm of new snow for most of the region, with up to 30 cm on the west coast. Strong southwest wind. Alpine low of -5 ºC.
Thursday
3-20 cm of new snow, localized distribution. Moderate to strong westerly wind. Alpine high -5 ºC.
Friday
Scattered flurries. Light southwest wind. Alpine high -5 ºC.
Saturday
Flurries. Moderate easterly wind. Alpine high -3 ºC.
More details can be found in the Mountain Weather Forecast.
