Avalanche Forecast
Issued: Apr 11th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Loose Wet.
jsmith,
Avalanche Canada
Lingering wind slabs may remain reactive to human triggers on lee aspects at treeline and above.
Watch for recently formed and reactive wind slabs as you transition into wind affected terrain.
Summary
Confidence
Moderate
Avalanche Summary
Several skier triggered small (size 1) 20 cm deep wind slabs were reported on northerly aspects at treeline near Mt. Washington on Monday.
Observations are limited at this time of year, please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.
Snowpack Summary
Around 25-50 cm of heavy, wet new snow exists between 1000-1400 m. Above 1400 m, dry snow has likely been redistributed into deeper deposits on north-facing terrain features by strong southerly winds. Below 1000 m, rain has saturated the snowpack.
The storm snow sits over a melt-freeze crust at mid-elevations, and over settling dry snow at high elevations on shaded slopes. The middle and lower snowpack is strong and well-bonded.
Weather Summary
Tuesday night
Partly cloudy with flurries; 5-10 cm / 20 km/h south ridgetop wind / Temperature at treeline around -3 C / Freezing level 600 m
Wednesday
Sunny / 10 km/h northwest ridgetop wind / Temperature at treeline around 3 C / Freezing level rising to 1400 m
Thursday
Cloudy / 10 km/h southwest ridgetop wind / Temperature at treeline around 0 C / Freezing level 1000 m
Friday
Mostly cloudy with isolated flurries; 3-10 cm / 30 km/h south ridgetop wind / Temperature at treeline around 1 C / Freezing level 1100 m
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, rocky, and wind effected areas where triggering slabs is more likely.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Problems
Wind Slabs
Lingering wind slabs may remain reactive to human triggers on lee aspects at treeline and above.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Expect the sunshine to trigger small wet loose avalanches on slopes that are still holding dry snow at upper elevations.
Aspects: East, South East, South, South West, West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 12th, 2023 4:00PM
