Avalanche Forecast
Issued: Mar 27th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Loose Wet.
zryan,
Avalanche Canada
Tune in to the changing conditions of elevation, aspect, and time of day.
Be cautious in wind-affected terrain and avoid steep sun-exposed slopes and overhead hazard during periods of strong sun.
Summary
Confidence
Avalanche Summary
On Sunday, sledders triggered several small (size 1) wind slabs with highmarks on southwest facing slopes and gullies in the alpine.
On Friday a few loose natural wet avalanches were reported on south aspects in the alpine. These avalanches occurred as a result of strong sun and were large (size 2).
If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.
Snowpack Summary
Strong northerly winds have created hard wind affected surfaces in alpine and exposed treeline terrain. In protected areas up to 30 cm of relatively undisturbed powder may exist. A sun crust exists on steep solar aspects in the alpine and all aspects but north at treeline.
Specific to Haines pass and below 1300 m the 50 cm of storm snow now has a stout and supportive melt freeze crust that has capped it. An additional 5 to 15 cm of new snow now overlies this melt freeze crust.
A buried weak layer of surface hoar can be found about 80 cm deep in Powder Valley, Tutshi, Paddy Peak and Haines pass areas, 150 to 200 cm around White Pass. This layer is most prominent on northerly slopes sheltered from the wind. On other aspects, this layer is a hard melt-freeze crust with weak facets around it. This layer has been most problematic in alpine terrain.
The remainder of the middle of the snowpack is consolidated and strong. Weak faceted grains are found near the base of the snowpack, particularly in thin snowpack areas.
Weather Summary
Monday night
Clear. Alpine temperatures drop to a low of -7 °C. Ridge wind light from the west. Freezing level at valley bottom.
Tuesday
A mix of sun and cloud. Alpine temperatures reach a high of -4 °C. Ridge wind 15-30 km/h from the northwest. Freezing level rises to 500 metres.
Wednesday
A mix of sun and cloud. Alpine temperatures reach a high of -4 °C. Ridge wind south 15-30 km/h. Freezing level rises to 500 metres.
Thursday
Mainly cloudy with isolated flurries. Alpine temperatures reach a high of -7 °C. Ridge wind 30-50 km/h from the south. Freezing level rises to 400 metres.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Wind Slabs
Northeast wind have redistributed the surface snow into fresh wind slabs on southerly aspects and in cross-loaded terrain.
Aspects: North, South East, South, South West, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
A weak layer of surface hoar and/or faceted grains around a hard crust sit in the mid snowpack. This layer is buried around 80 cm in the eastern portions of the region and up to 200 cm around White Pass and Haines Pass.
This layer has previously produced widely propagating avalanches in alpine terrain and it is capable of being remotely triggered from a distance. The most likely area for riders to trigger it is in wind-sheltered, north-facing terrain, and in rocky terrain where the snowpack is thin.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Warm temperatures and strong sun may create wet loose avalanche in steep south-facing terrain.
Keep in mind, that wet loose avalanches may start small but they can grow and push you into dangerous terrain.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 28th, 2023 4:00PM
