Avalanche Forecast
Issued: Apr 16th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Cornices.
jleblanc,
Avalanche Canada
Large cornices are hard to pinpoint when travelling on a ridge top and can be easily triggered by the weight of a person; so stay well back. Looking at approaching big lines? Make sure to read this new blog.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations. Forecast snowfall amounts are uncertain.
Weather Forecast
A surface low tracking across Montana is spilling over the region tonight. By Sunday, a weak ridge of high pressure will build over, bringing a drier day. Early next week, a low-pressure system from the BC Coast will bring light to moderate precipitation into the interior ranges.
SATURDAY NIGHT: 3-5 cm localized accumulations / light to moderate easterly wind / treeline low around -8 C / freezing level at valley bottom.Â
SUNDAY: Partially cloudy with scattered flurries / light southwest wind / treeline high around +2 C / freezing level rising to 1600 m and back at valley bottom at night.
MONDAY: Increasing cloudiness / moderate south wind gusting 40 km/h / treeline high of +2 C / freezing level rising to 1600 m and remaining elevated at night / moderate overnight snowfall (5-10 cm)
TUESDAY: Snow 5-10 cm at higher elevation / moderate southwesterly wind gusting 50 km/h / treeline high around +1 C / freezing level around 1500 m
Avalanche Summary
Observations are very limited this time of year. On Friday, numerous small loose dry avalanches (up to size 1) were observed on various aspects of Old Glory Mountain. For the current conditions around Rossland, take a look here.Â
If you are getting out in the backcountry, please consider contributing to the Mountain Information Network by sharing snow / riding conditions.Â
Snowpack Summary
Friday, localized areas have seen some convective flurries (up to 5 cm). The recent snow (up to 20 cm) sits on a widespread melt-freeze crust formed on April 8. Periods of strong northeast wind earlier this week have redistributed this recent snow in exposed terrain forming localized wind slabs and hard-pressed snow. Cornices have likely grown large recently, but are expected to be relatively stable with the current cold temperatures. A sun crust has been formed on steep sun-exposed slopes. Multiple crusts exist in the upper snowpack, which is currently well bonded with the ongoing cold conditions. The middle and lower snowpack are currently well settled and strong.
Terrain and Travel
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
- Carefully evaluate steep lines for wind slabs.
- Cornices often break further back than expected; give them a wide berth when traveling on ridgetops.
Problems
Cornices
Cornices have likely grown large recently but are generally not expected to fail naturally with the current and forecasted conditions. However, human-triggered cornices are possible so give cornices a wide berth when travelling on ridges and watch for signs that they may be weakening if they are exposed to extended periods of sun.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 17th, 2022 4:00PM
