Avalanche Forecast
Issued: Mar 26th, 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
Northerly winds may have formed fresh, reactive wind slabs in exposed areas.
Be cautious as you enter wind-affected terrain and avoid steep sun-exposed slopes and overhead hazard during periods of strong sun.
Summary
Confidence
Avalanche Summary
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).
On Thursday a few loose dry avalanches were reported on all aspects in the alpine. These avalanches were small (size 1.5).
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
Variable strong winds have redistributed 50 cm of recent storm snow creating hard wind affected surfaces in alpine and exposed treeline terrain. In protected areas in the alpine 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
Sunday night
Clear with cloudy periods. Alpine temperatures drop to a low of -15 °C. Ridge wind northeast 20 to 50 km/h. Freezing level at valley bottom.
Monday
Mainly sunny. Alpine temperatures reach a high of -5 °C. Ridge wind 10-20 km/h from the west. Freezing level rises to 400 metres.
Tuesday
A mix of sun and cloud. Alpine temperatures reach a high of -5 °C. Ridge wind 15 to 40 km/h from the northwest. Freezing level rises to 400 metres.
Wednesday
Sunny with cloudy periods. Alpine temperatures reach a high of -5 °C. Ridge wind southwest 20-45 km/h. Freezing level rises to 500 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
Yesterday's northerly outflow winds may have redistributed the surface snow into fresh, reactive wind slabs on southerly aspects and in cross-loaded terrain. Previously wind was out of the south and older, stubborn wind slabs may still be found on a variety of aspects.
Aspects: All aspects.
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 27th, 2023 4:00PM
