Avalanche Forecast
Issued: Jan 9th, 2017 4:32PM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeRidgetop wind speeds are uncertain for Tuesday. If northerly winds are strong, new wind slabs can be expected on all aspects.
Summary
Confidence
Moderate - Wind speed and direction is uncertain on Tuesday
Weather Forecast
Tuesday: Mix of sun and cloud / Moderate north winds / Alpine temperature at -25Wednesday: Clear skies / Moderate north winds / Alpine temperature at -18Thursday: Mix of sun and cloud / Strong northwest winds / Alpine temperature at -14
Avalanche Summary
No new avalanches were reported on Sunday. I'd expect a new round of wind slab activity in response to new snow and wind on Sunday night and Monday. Northerly winds on Tuesday may promote a reverse loading pattern increasing the likelihood of wind slab activity on a variety of aspects.
Snowpack Summary
Up to 20 cm of low density snow fell on Sunday night and Monday. Moderate to strong southwest winds are expected to have shifted these fresh accumulations into wind slabs at treeline and above. Recent snow has also covered old, thicker wind and hard slabs from previous wind events. Persistent and deep persistent weakness in the mid and lower snowpack are giving variable results in snowpack tests, but are generally most touchy in shallow snowpack areas. Recent snowpack tests gave moderate but resistant results on facets and/or surface hoar buried mid-December where it was found down 45 cm, and hard but sudden collapse results on the facet/crust weakness down 116 cm near the base of the snowpack.
Problems
Wind Slabs
New snow on Monday was likely shifted by southwest winds into reactive wind slabs in exposed high elevation terrain. On Tuesday, a switch to northerly winds may promote a reverse loading pattern and fresh wind slabs may exist on all aspects.
Be cautious as you transition into wind affected terrain.Avoid areas where the snow feels stiff or slabby.Be alert to conditions that change with aspect and elevation.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Triggering a weak layer of facets and/or surface hoar buried mid-December may still be possible in parts of the region where the snowpack is shallower. Dig down and test for weaknesses before committing to larger terrain features.
Choose regroup spots that are out of avalanche terrain.Avoid likely trigger spots such as steep and rocky areas with a shallow snowpack.Only expose one person at a time to larger slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 10th, 2017 2:00PM