Avalanche Forecast
Issued: Mar 26th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Persistent Slabs and Wind Slabs.
zryan,
Avalanche Canada
Warm air and rain may destabilize the snowpack at lower elevations, with new wind slabs potentially forming up high.
Head out with a conservative mindset and adjust your travel plans accordingly to the changing conditions of elevation and time of day.
Summary
Confidence
Weather Forecast
SATURDAY NIGHT: Cloudy with precipitation, 5 cm of new snow accumulation at higher elevations. 15-40km/h southwest winds. Freezing level around 1000 m.
SUNDAY: Cloudy with precipitation, 5-10 cm of new snow accumulation at higher elevations. 20-45 km/h southwest winds. Freezing level rising to 2200 m.
MONDAY: Cloudy with precipitation, 5-10 cm of new snow accumulation at higher elevations. 15-40 km/h northwest winds. Freezing level around 1800 m.
TUESDAY: Mainly clear. 10-30 km/h southwest winds. Freezing level rising to 2200 m.
Avalanche Summary
Two persistent slab avalanches were reported on Friday. One was a large (size 3) natural avalanche that was observed at 2000 m on an east aspect. The other was a result of explosive control on a cornice that initiated a large persistent slab avalanche (size 3) on a northeast aspect in the alpine. Explosive control also produced several large (size 2-3) cornices that did not initiate slab avalanches on the slopes below.
Two persistent slab avalanches were reported on Thursday, both on south-facing alpine slopes. One was a large (size 2.5) natural avalanche and the other was a small (size 1.5) slab remotely triggered by riders.
Widespread loose wet and wet slab avalanche activity occurred during the warm-up on Wednesday and Thursday.
Snowpack Summary
Above 2000 m, 5 to 15 cm of recent snow and southwest winds may have formed small wind slabs in lee terrain features. Below 2000 m a refrozen crust can be found. This crust is expected to break down throughout the day at low elevations with rain and warm temperatures. Below the crust, the top 10-30 cm of the snowpack is moist. At very low elevations, the snowpack may become wet and isothermal.
A weak layer may be found around 50 to 100 cm deep. The layer consists of surface hoar crystals in treeline terrain on northerly aspects or weak faceted grains above a hard melt-freeze crust on sun-exposed slopes (i.e., east, south, west). It has been reactive between 1800 and 2300 m but given the recent rain, it is most likely to be triggered between 2000 and 2300 m. It should still be treated as suspect if you find it in your riding area.
The remainder of the snowpack is well-bonded.
Terrain and Travel
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Carefully evaluate steep lines for wind slabs.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Problems
Loose Wet
Rain at lower elevations may cause the surface crust to break down. Pay attention to how thick and supportive the crust is, and avoid steep slopes when the crust starts to weaken and become unsupportive to your weight.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Persistent Slabs
A weak layer may be found around 50 to 100 cm deep. The layer is most likely to be triggered between 2000 and 2300 m, on all aspects. The likelihood of triggering this layer is decreasing, but the consequence of doing so would be high.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Wind slabs may be found in steep, lee terrain features in the alpine and exposed treeline.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 27th, 2022 4:00PM
