Buried weak layers may become increasingly reactive with rising temperatures this weekend. Be ready to dial back your terrain choices Saturday if freezing levels rise above treeline.
Wind slabs sitting over a weak layer of facets have shown wide propagation and sensitivity to human triggers. Avoid areas of wind-loaded snow in leeward terrain features at upper elevations.
This problem encompasses two active weak layers. A layer of facets is buried 30-50 cm deep and a crust/facet/surface hoar layer 60-90 cm deep. Avalanches have been observed on both of these layers in recent days.
Wind slabs and persistent slabs have been reactive in recent days, both naturally and to human triggers. Slabs have shown high sensitivity with wide propagation and remote triggers, averaging size 1.5-2, but up to size 3 (very large).
30-50 cm of recent snow sits on facets formed during the mid January cold snap. At upper elevations, this snow has been redistributed by wind.
A few layers of note exist in the mid snowpack. Another crust/facet/surface hoar layer buried in early January is now 60-90 cm deep. A layer of surface hoar buried in early December is now 130+ cm deep. This layer is of most concern above 2000 m where a robust crust doesn't exist above it.
Friday night
Mostly cloudy with flurries bringing around 5 cm of new snow. Southwest alpine wind 40-50 km/h. Treeline temperature -3 °C.
Saturday
Mostly cloudy with scattered flurries brining up to 5 cm of new snow. Southwest alpine wind 30-40 km/h. Treeline temperature 0 °C. Freezing level 1700 m.
Sunday
5-10 mm of mixed precip then a mix of sun and cloud. Southwest alpine wind 40-50 km/h. Treeline temperature +1 °C. Freezing level 2300 m.
Monday
Mostly cloudy with around 10 mm of mixed precip. Southwest alpine wind 30-40 km/h. Treeline temperature +3 °C. Freezing level 3000 m.
More details can be found in the Mountain Weather Forecast.
