Avalanche Forecast
Issued: Mar 25th, 2023 11:30AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
wlewis,
Avalanche Canada
Watch for changing conditions as you travel through different aspects and be aware of active wind loading occurring. Potential for wind slabs exist in all wind affected terrain.
Keep an eye on snow surface conditions throughout the day - brief periods of strong sunshine can quickly increase reactivity on sun affected slopes.
Summary
Confidence
Avalanche Summary
Wind slabs have been reported on all aspects over the last 3 days.
Most recent activity has occurred on west facing slopes from easterly winds redistributing new snow over a crust. Earlier in the week natural wind slab activity was reported on east facing slopes from the previous strong westerly winds.
Check out these MINS for recent conditions, from 10 Mile Valley, near Glenburnie, and Jumbo Brook.
Snowpack Summary
Around 10 cm of fresh storm snow fell on Friday. This falls over a crust at low elevations and on sun affected slopes to ridgeline. In wind affected areas this has been redistributed in to wind slabs sitting on the crust.
Below this crust, up to 50 cm of settling snow from last weekend's storm was heavily redistributed by strong westerly winds into deep deposits on east facing slopes. Other aspects may have been stripped back to hard layers or rock by this wind event.
A widespread thick and supportive crust exists 30-80 cm deep. Recent test results have shown this layer is mostly bonding well to the snow above, however there is potential for avalanches to occur on this layer where the bond is weaker - in thin and rocky snowpack areas. Avalanche activity is unlikely below this crust, as the lower snowpack is dense and bonded with crust layers throughout.
Weather Summary
Saturday: Mostly cloudy with trace amounts of snow possible. Northerly wind 30-40 km/hr. Freezing levels 300 m. Alpine high of -2 °C.
Sunday: Clear skies to start the day, with increasing cloud. Isolated flurries possible. Southeast winds, 30-40 km/hr. Freezing levels 400 m. Alpine high of -1 °C.
Monday: Mostly cloudy with isolated flurries possible. East/southeast winds, 30-50 km/hr. Freezing levels 300 m. Alpine high of -2 °C.
Tuesday: A mix of sun and cloud with isolated flurries possible. Northeast winds, 30-40 km/hr. Freezing levels 200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Wind slabs are most reactive during their formation.
- Carefully evaluate steep lines for wind slabs.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs may be poorly bonded to the underlying crust.
Problems
Wind Slabs
Wind slabs can be found throughout the alpine and treeline, on all aspects due to recent variable winds. Newer wind slabs are forming over a crust from easterly winds, in north and west facing terrain features. Although slabs may be small, these are reactive to human triggers.
East facing slopes have also produced recent wind slab activity, likely to be larger but more stubborn to human triggers.
Approach wind loaded features around ridgelines with caution. Watch for visibly wind affected surfaces (wind ripples, sastrugi) and for dense, drummy sounding snow.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 28th, 2023 11:30AM
