Avalanche Forecast
Issued: Feb 19th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
ahanna,
Avalanche Canada
The sun is getting higher in the sky at this time of year and can pack a punch so be ready to step back from steep south aspects showing signs of solar warming. Keep avoiding shallow rocky or wind affected start zones.
Summary
Confidence
Weather Forecast
Wednesday night: Clear. Light to moderate west wind. Alpine low -14 C. Freezing level valley bottom.
Thursday: Sunny. Moderate to strong west wind. Alpine high -3 C. Freezing level 1500 m.
Friday: Sunny. Moderate to strong west wind. Alpine high -3 C. Freezing level 1500 m.
Saturday: Sunny. Moderate to strong west wind. Alpine high -3 C. Freezing level 1500 m.
Avalanche Summary
Wednesday saw some minor loose wet activity originating from rock bands on steep solar slopes.
Natural size 2 persistent slab avalanches on the February rain crust were observed Monday and Tuesday. One was a case of a wind slab stepping down in a fan.
There have been no reports of deep persistent slab activity on the basal weak layers for over a week. The most recent is described in this MIN report from February 11 and this MIN on February 9th.
Snowpack Summary
A thin sun crust may be found on steep solar aspects. Alpine and exposed treeline areas have seen extensive wind effect, involving multiple layers of wind slab. Soft snow can still be found in sheltered areas.
A thick rain crust from early February sits 20-70 cm below the surface up to 2100 m. Recent avalanche activity has been observed at the faceting interface between this crust and overlying snow.
A well consolidated mid-pack overlies generally weak basal facets that may be possible to trigger in isolated shallow rocky start zones or with large loads.
Terrain and Travel
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
- Caution around slopes that are exposed to cornices overhead.
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Wind Slabs
Where soft snow remains available for transport in the alpine, wind slab development will likely resume as winds pick up in the afternoon. Freshly wind loaded pockets will be most reactive to human triggers. Keep in mind that if triggered, wind slab avalanches can serve as triggers for deeper layers.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 20th, 2020 5:00PM
