Avalanche Forecast
Issued: Jan 19th, 2023 4:00PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeUpdated at 7:10 AM Pacific: Another storm hit Pine Pass overnight creating ongoing dangerous avalanche conditions. Choose conservative terrain and give the storm snow a little more time to settle before stepping out.
Summary
Confidence
Moderate
Avalanche Summary
No new avalanches were reported in the past few days in the region.
On Saturday, a large (size 2) avalanche was observed at Hassler. It was potentially remotely triggered by a snowmobiler, and propagated widely across a sparsely treed slope.
Although there has been a decline in observed avalanche activity, triggering a large persistent slab avalanche remains possible and terrain should be chosen with care.
Snowpack Summary
15 cm of new snow fell overnight at Pine Pass.
Storm slabs will likely be found on exposed terrain at treeline and above. At lower elevations, a rain crust exists near the surface, with reported elevations extending up roughly 1200 m.
Snowpack depths are shallower than normal, and several buried weak layers have been a concern over the past few weeks. One is a recently buried surface hoar layer found 20 to 40 cm deep in sheltered terrain features at treeline and above. At this same depth, a crust exists on steep south facing slopes. Another layer of facets, crust, and surface hoar was buried around Christmas and is now 40 to 70 cm deep. Finally, a layer of large, weak facets buried in November is found near the bottom of the snowpack. This layer is likely most problematic in alpine terrain, where shallower avalanches could scrub down to these basal facets.
Recent observations suggest the buried weak layers are gaining strength, but not enough to trust them in high consequence terrain.
Weather Summary
Thursday Night
Mostly cloudy with flurries bringing up to 5cm of new snow. Strong westerly winds and a low of -6 at 1500m.
Friday
Mostly cloudy with flurries bringing around 5cm of new snow. Strong west winds and a high of -2 at 1500m.
Saturday
Cloudy with up to 15cm of new snow. Strong southwest winds and a high of -3 at 1500m.
Sunday
A mix of sun and cloud with light flurries bringing trace amounts of new snow. Light to moderate northwest winds and a high of -5 at 1500m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Dial back your terrain choices if you are seeing more than 20 cm of new snow.
- Be carefull around freshly wind loaded features.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Problems
Storm Slabs
Rider triggerable storm slabs can be found at upper elevations, especially in exposed terrain at treeline and above from southerly winds.
Be aware that storm slab avalanches could step down to deeper layers resulting in a larger and more destructive avalanche.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Several buried weak layers remain a concern for human triggering. At treeline elevations, the main concern is surface hoar and crust layers in the middle of the snowpack, especially on steep convex openings. In the alpine, the main concern is weak facets at the bottom of the snowpack, especially on rocky slopes with variable snow depths.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 20th, 2023 4:00PM