Avalanche Forecast
Issued: Apr 19th, 2023 1:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.
mkoppang,
Avalanche Canada
Convective flurries continue to bring snow to the region with some areas seeing up to 30cm (Aster/Mt Joffre area). Ski quality is good on planar slopes where you are sliding on top of the crust. Any slope that has not yet released should be treated as suspect. Soon we will hopefully be into a good melt freeze spring cycle!!!
Summary
Confidence
High
Avalanche Summary
Numerous loose dry avalanches up to sz 1.5 were observed on all aspects. No new slab avalanche activity was noted but visibility was very limited throughout the day.
Snowpack Summary
Up to 20cm of new snow via convective flurries was seen in the Commonwealth area Wednesday at treeline. Winds were generally calm so there was little in the way of new windslabs developing. The new snow was sluffing easily from steep terrain and in areas where it was overlying the previous melt freeze/rain crust so be aware of the potential for loose dry avalanches to run far and fast. Moist snow was encountered in valley floors by 1100am so continue to start early!Forecasters continue to track persistent weaknesses down anywhere from 40 to 100cm on polar aspects. These weaknesses are highly variable in nature and travelers should take the time to dig down and evaluate the snowpack frequently. Also, the lingering deep persistent slab problem is still alive and well.
If the sun comes out stability will deteriorate quickly so pay attention to the incoming radiation on aspects you are travelling on or under. Early starts and finishes are a great way to deal with some of these issues.
Weather Summary
A murky next few days with convective flurries being the norm for the region. Storms pass over and within a few mins 3-5cm of snow can fall followed by blue sky. This is common in spring and snowfall amounts can vary even by drainage. Winds over the next 24hrs are still in the light range out of the W-NW with overnight lows around -10C. When cloudy conditions persist overnight lows may not be as cold as has been forecast so use the weather stations for the region to assess quality of freeze. If the sun comes out, it quickly packs a punch and moist snow develops in minutes. The intense solar radiation can also decrease stability on solar aspects so keep a close eye on aspect and weather. Lots of weather changes in spring!!!!
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Wind Slabs
Long immediate ridgelines in alpine terrain.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
The persistent layer is down roughly 100cm. May wake up again with increasing precipitation. North aspects is where this layer has been most active.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Shallow snowpack areas are an area of special concern, especially with intense solar radiation and/or daytime heating.
Great evidence of this problem avalanching is easy to find along the spray road right now.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 21st, 2023 4:00PM
