Danger was on the rise Friday as fresh slabs formed with new snow at the high end of forecast amounts. More overnight snow and wind should keep slabs primed for human triggers on Saturday. Be ready to step back if snowfall exceeds the forecast. It wouldn't be the first time!
New snow and southwest wind will likely form touchy new wind slabs over Friday night and possibly into Saturday. Winds are expected to shift north in the Saturday evening to complicate slab distribution. Increase caution and identify leeward slopes likely to hold new slabs if you're entering exposed terrain.
Friday night: Cloudy with continuing flurries bringing about 5 more cm of new snow. Moderate southwest winds.
Saturday: Cloudy with easing flurries bringing up to 5 cm of new snow, increasing again overnight. Light to moderate southwest winds, easing over the day and increasing, shifting north again overnight. Alpine high temperatures around -10.
Sunday: A mix of sun and cloud. Moderate to strong north winds easing over the day. Alpine high temperatures around -14.
Monday: Becoming cloudy. Moderate southwest winds. Alpine high temperatures around -10.
Reports from the White Pass area over the midweek showed fairly minimal wind slab reactivity in areas where wind has actively been moving loose snow around.
A rapid change in conditions was observed Friday morning as flurries and elevated winds initiated a new period of wind slab development. This pattern of light accumulation amid elevated, shifting winds should sustain through Saturday night.
Light new snow amounts and elevated winds reignited wind slab formation in the White Pass area on Friday morning. Similar conditions will prevail through the first couple of days of the forecast period.
The new snow has mainly buried wind affected surfaces in exposed areas. Previous wind slabs have largely stabilized, but concern still exists for the ability of large triggers like cornices or machines to trigger older large, hard wind slabs in alpine areas that are now obscured by new snow.
There are no deeper concerns around White Pass.
Substantial spatial variability likely still exists in the snowpack around the Tutshi Lake/Paddy Peak area. Terrain here should be assessed on a slope by slope basis, as lingering snowpack weaknesses may still exist.
The Wheaton's continental snowpack is dominated by hard wind slabs overlying sugary facets and depth hoar. It's an untrustworthy snowpack structure that requires conservative terrain selection and diligent travel habits.
