Expect to see reactive storm slab conditions, especially in wind loaded areas. Choose conservative terrain and avoid overhead hazard.
50-70 cm of snow sits on a persistent weak layer that was buried near the end of January. This layer consits of a melt freeze crust in some areas, surface hoar in shetered areas, and facets in some areas as well.
Storm slabs will likely continue to be reactive on Tuesday, especially in wind loaded areas.
MONDAY NIGHT - Flurries, 10-15 cm / strong southwest wind / alpine low temperature near -4 / freezing level 1600 m
TUESDAY - Flurries, 5 cm / moderate to strong southwest wind / alpine high temperature near -5 / freezing level 1500 m, dropping to valley bottom overnight
WEDNESDAY - A mix of sun and cloud / light northwest wind / alpine high temperature near -10
THURSDAY - Mainly cloudy with a few flurries / moderate west wind / alpine high temperature near -9
Human triggered avalanches are expected to be easy to trigger on Tuesday, especially in wind loaded areas.
At the time of publishing, there were a few reports of size 1.5-2 explosives triggered storm slab avalanches in the region on Monday.
There were numerous size 1-1.5 human and explosives triggered avalanches reported on Sunday. Several of these were reported to have failed on the recently buried persistent weak layer.
On Thursday and Friday, there were numerous reports of size 1-2 human triggered avalanches. These avalanches failed on the persistent weak layer of surface hoar that was buried in late January.
10-15 cm of snow is expected on Monday night, with another 5 cm on Tuesday.
There is now about 50-70 cm of recent storm snow sitting above a persistent weak layer that consists of a melt-freeze crust in many areas, on a sun crust on steep south-facing slopes, and large surface hoar in sheltered areas.
There are potentially several more layers of surface hoar in the upper snowpack, with the most notable one down about 60-120 cm. This layer was buried in early January.
A couple of crusts surrounded by weak faceted grains are buried deep within the snowpack. The upper layer is 150 to 200 cm deep and the lower one is near the ground.
