Avalanche Forecast
Regions: Purcells.
If you are stepping into bigger terrain, carefully evaluate your line for windslab and loose wet avalanche potential.
Confidence
High - We have a good understanding of the snowpack structure and confidence in the weather forecast
Weather Forecast
FRIDAY NIGHT: Partly cloudy with a drizzle of rain. Light southwest ridgetop winds, trending to moderate west in the high alpine. Freezing level rising to 2000 m through the day.
SATURDAY: Partly cloudy. Possible light rain/snow in the afternoon. Light southwest ridgetop wind trending to moderate west in the high alpine. Freezing level around valley bottom overnight, rising to 2100 m through the day.
SUNDAY: Partly cloudy. Possible light rain/snow. Light southwest ridgetop wind trending to strong in the high alpine. Freezing level around valley bottom overnight, and rising as high as 2700 m through the day.
MONDAY: Mostly cloudy. Possible light rain/snow. Light southwest ridgetop winds with some periods of moderate in the high alpine. Freezing level around 2100 m.Â
Avalanche Summary
No new and notable avalanches were reported before 4 pm on Friday.
On Thursday, many loose wet avalanches up to size 1.5 were reported on slopes getting cooked by the sun. Also, a few large (up to size 3) cornice falls were reported that didn't trigger other avalanches as they fell.Â
Snowpack Summary
Recent snow and moderate wind have formed small pockets of windslab in the alpine . Refrozen crust on all aspects as high as 2300 m, softening in the afternoon at low elevations, and on steep, sunny slopes. Recent warm temperatures, sun, and rain have made the top 5-15 cm of the snowpack moist.
30 to 75 cm below the snow surface, you'll find a frozen sun crust on solar aspects. This layer was buried in early March, and it was a cause of several avalanches last week, but the recent warm weather seems to have helped this layer heal.Â
The lower snowpack is generally strong and well bonded.
Terrain and Travel
- If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
- Be alert to conditions that change with elevation.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
- Avoid steep slopes when air temperatures are warm, it is raining, or solar radiation is strong.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Avalanche Problems
Wind Slabs
Westerly winds have redistributed up to 10 cm of recent snow into small wind slabs on lee features in the alpine and treeline.
Use extra caution near ridgetops, especially when the slope underneath is steep and/or hard. Even a small avalanche can knock you off balance, so consider the consequences of a fast slide down a hard slope.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Loose Wet
Freezing levels are falling overnight, but the surface snow may not solidly refreeze. Loose wet avalanches have been most common on steep, sunny slopes.
Paying close attention to how thick and supportive the surface crust is throughout the day, and sticking to shady slopes if the sun is packing a punch are good ways to avoid any wet loose avalanche problems.
Aspects: South East, South, South West, West.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2