Bring an assessment mindset when you head up to check on the aftermath of the storm. Surface snow may still be saturated enough for wet avalanches. Double your caution if you find dry snow.
Areas of the highest alpine where new snow remains dry or minimally affected by rain may hold reactive wind slabs scattered around leeward terrain features.
A 40 cm-deep combo of surface hoar, facets, and crust saw a big test with Saturday's storm. Until we know it's either been cleaned out or capped by crust, be wary of larger triggers like falling cornices or machines in north-facing alpine.
Saturated surface snow at lower elevations may still produce wet avalanches with a trigger in steep terrain on Sunday, particularly with any solar warming. Surface crust formation, where it occurs, will neutralize this problem.
On Thursday, several small (up to size 1) natural and human triggered wind slab avalanches were reported in the recent storm snow.
Natural avalanche activity should peak on Saturday. Sunday will be a day to reassess what problems may still be in play.
Mixed precipitation, mainly rain, will continue making a mix of saturated (below treeline), wet new snow (treeline), and deep, heavy, but likely rain affected (alpine) surface conditions Saturday night.
As temperatures cool, anywhere new snow remains dry will likely hold reactive surface instabilities like wind slabs. Crust formation should soon neutralize wet loose problems and cap storm instabilities at lower elevations.
A sandwich of surface hoar and faceted snow overlying the late January crust 40 cm deep (and counting) has produced concerning snowpack test results though the week. High elevation rain is putting it to the test Saturday. Will it survive?
The lower snowpack is well settled.
Saturday Night
A few cm of wet snow accumulating after heavy rain to the alpine. 50 to 70 km/h southwest ridgetop wind. Freezing level falling to 1300 m.
Sunday
Mostly cloudy with wet flurries and rain beginning in the afternoon, minimal accumulation. 30 to 50 km/h south ridgetop wind. Freezing level 1300 m - 1600 m.
Monday
Mostly cloudy with scattered wet flurries, up to about 5 cm accumulation. 40 to 70 km/h variable ridgetop wind. Freezing level around 1300 m.
Tuesday
Cloudy with scattered wet flurries continuing from overnight, 10 - 20 cm total accumulation, mainly in the alpine. 40 - 60 km/h variable ridgetop wind. Freezing level reaching 1400 m.
More details can be found in the Mountain Weather Forecast.
