Another day of warm weather and some sunny skies. If the snowpack is wet and mushy it could avalanche easily. Start and finish your day early and avoid sun-exposed terrain.
Summary
Confidence
Weather Forecast
Overnight Wednesday: Mostly clear with some upper-level cloud entering the region. Light northwest wind and freezing levels dropping to 700 m.
Thursday: Mix of sun and cloud with light precipitation 2-5 mm. Ridgetop wind light from the northeast. Alpine temperatures near +3 C and freezing levels 2100 m.
Friday: A mix of sun and cloud. Light winds from the East. Alpine temperatures near +1 C and freezing levels 1800 m.
Saturday: Snow 10-20 cm. Alpine temperatures near -2 and freezing levels 1600 m.
Avalanche Summary
There have been no recent avalanche reports since last Saturday.
Last weekend, reports of natural loose wet avalanches size 2-3 on solar aspects continued. Explosive work produced size 2-3.5 wet slab avalanches, failing on crusts in the upper snowpack and gouging to the ground as they ran to near valley bottom.
Snowpack Summary
The snow surface consists of a melt-freeze crust on all aspects of the mountain top. Only high alpine slopes above 2100 m and due North may still hold some softer, dryer snow. With a limited freeze overnight and rising freezing levels by Thursday afternoon, this crust may break down quickly with mostly wet snow surfaces. There are no layers of concern in the snowpack, which has been melting and settling over the past week. Lower elevations have mostly been isothermal and melting away rapidly.
Large cornices loom along many ridgelines. They are weak and very unpredictable.
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Terrain and Travel
- Avalanche hazard is expected to to increase througout the day, think carefully about your egress.
- Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Loose Wet
Wet loose avalanche activity can also be expected on sun-exposed slopes. These avalanches are generally smaller than wet slabs but they can gather mass as they travel and reach low elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are at their largest at this time of year, and become weaker with warm temperatures and solar radiation.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 22nd, 2021 4:00PM
