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 and Cornices.
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.
Summary
Confidence
Weather Forecast
Wednesday night: Clear. Light southwest winds. Alpine low -16 C. Freezing level 1000 m.
Thursday: Sunny. Light west wind increasing to strong at ridgetop. Alpine high -2 C. Freezing level 1300 m.
Friday: Sunny. Moderate west wind, strong at ridgetop. Alpine high -2 C. Freezing level 1400 m.
Saturday: Sunny. Moderate west wind, strong at ridgetop. Alpine high -1 C. Freezing level 1500 m.
Avalanche Summary
Explosive control work Monday and Tuesday produced mostly size 2 cornices, some triggering thin slabs on slopes below.
There have been two reports of avalanches running on the early February rain crust. Explosive control work produced a size 2 with crown depth up to 80 cm on Tuesday. A skier triggered size 2 on a southeast aspect is described in this MIN report from Sunday.
Snowpack Summary
A thin sun crust may be found at the surface on steep solar aspects. Variable wind affect in the alpine and near treeline with soft slabs in immediate lees.
A thick rain crust sits 30-60 cm below the surface, up to 2100 m. Recent avalanche activity has been observed at the faceting interface between this crust and overlying snow.
The bottom 20 cm of the snowpack consists of basal facets and decomposing crusts that have not been an active avalanche problem since December, but could reemerge as a problem after sustained warming.
Terrain and Travel
- Avoid exposure to slopes that have cornices overhead.
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
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 deposits will be most reactive to human triggers.
Below 2100 m, deep wind slabs sit on a thick melt freeze crust which could serve as an excellent bed surface.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Natural cornice falls have been reported recently and will likely continue as the sun stays out over the next few days. Cornice falls are dangerous in their own right but they may also trigger avalanches on slopes they impact.
Aspects: North, North East, East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 20th, 2020 5:00PM
