Avalanche Forecast
Issued: Apr 13th, 2023 4:00PM
The alpine rating is Wind Slabs, Persistent Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeBig temperature swings are the norm these days. Expect a rapid decrease in stability/increase in hazard as the sun comes out, or if air temperatures increase.
Summary
Confidence
Moderate
Avalanche Summary
The natural cycle continued today, although its hard to figure out what's new and what's old. A sz2.5 solar triggered avalanche was witnessed today on a steep alpine slope.
Snowpack Summary
Cooler temperatures have helped stabilize the snowpack where previously it lacked structure and was rain soaked. This is mainly below 2200m or just below treeline. Above this elevation the snow was drier and windslabs formed with the strong SW flow. These windslabs are overlying a variety of different surfaces from crusts on solar aspects to dry snow on more polar. Carefully evaluate this bond as you travel. A deeper persistent layer down 1m was active in many avalanches over the past few days. This layer was most active on N and E aspects. Treat any area that have not slid as suspect and requires careful evaluation or imply avoidance. Deeper in the snowpack the weak facets and depth hoar at the base of the snowpack is still there. As temps warm up and this layer begins to settle and squish out it will improve and begin to bond but for now, its still a layer to think about as you travel. Thin areas is where you may be able to trigger this weakness.
Weather Summary
Tomorrow will start with mostly clear skies, but by mid morning clouds will build. An overnight low of about -13 is expected with a rise in temperatures later in the morning. The high will be -3, but with the sun factored in low elevation areas will be above zero by noon. Convective flurries will appear in the afternoon, giving a modest 2cm. Winds will be light from the SW. Freezing level 2100m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
Windslabs in the recent storm snow should be expected at treeline and above. Evaluate the bond with the underlying snowpack which is highly variable. There is lots of uncertainty at this interface currently.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
The persistent layer down 1m has been active due to recent snow loads. It also appears to be sensitive to heat.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
This layer has calmed down a bit, but if it warms up quickly expect it to come back to life.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 14th, 2023 4:00PM