Avalanche Forecast
Regions: Purcells.
Confidence
Fair - Due to limited field observations
Weather Forecast
An upper trough will move through the Interior tomorrow, while the NW flow will bring cooler, dryer air and decent pulses of precipitation.Saturday: Overcast. Light-moderate precipitation amounts. Ridgetop winds blowing moderate from the NW. Freezing levels near 1600 m.Sunday/Monday: A ridge of high pressure will bring a mix of sun and cloud, with cooling and dryer conditions. Freezing levels will be near 1000 m during the afternoon and falling to valley bottom overnight.
Avalanche Summary
No new avalanche activity has been reported.
Snowpack Summary
Up to 10 cm of new snow overlies a variety of old snow surfaces. These consist of melt-freeze crusts, buried surface hoar and surface facets. Touchy wind slabs exist on lee slopes and behind terrain features. Cornices on ridgelines have grown large, and pose a threat to slopes below.Deeper in the snowpack a weak interface buried in early April is down about 60-120 cm and consists of a crust on solar aspects, and surface hoar on high-elevation northerly aspects. Earlier this week, very large avalanches were reactive on this interface in the neighboring Glacier National Park. The bond may be getting stronger, but I would still use caution and be suspicious of large, steep upper elevation slopes.
Avalanche Problems
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 4
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 1 - 6