Keep it simple ! The warm weather and continued precipitation is beginning to subside. Utilize simple terrain as you give the snowpack time to cool and heal.
Wind loaded features are the primary concern. Watch for wind slabs in sheltered terrain and expect reactivity to be greatest in areas they are sitting over surface hoar.
Strong to extreme westerly winds have likely stripped west facing slopes and deposited snow lower down on north and east facing slopes.
Watch for mid slope terrain features like rollovers. A reactive surface hoar layer can be found down 40cm in protected areas up to 2000 m in elevation.
On Monday explosive avalanche control produced several small (size 1.5) wind slabs
On Sunday 1 large avalanche (size 2) was triggered utilizing explosives on a east aspect at 1850 m. This avalanche ran on a surface composed of facets with a crown depth that was on average 40cm deep and ran for 200 meters.
On Friday, wind slabs were reported to size one from natural and human triggers.
If you are heading into the backcountry please consider filling out a Mountain Information Network report.
The high freezing levels and precipitation in the form of rain has significantly moistened the upper snowpack Strong westerly winds continue to redistribute recent snow and is forming wind slabs at higher elevations. On south facing slopes wind slab could have formed over a sun crust. A layer of surface hoar down around 40cm can be found in sheltered terrain on all aspects up to 2000m. Reactivity will increase where wind slabs sit over this surface hoar, especially as temperatures increase on Tuesday.
A weak layer consisting of facets and a crust formed in November is now buried around 60cm deep.
In general, the snowpack is quite weak and faceted with average snowpack depths of around 150cm at treeline.
Tuesday Night
Cloudy as wet snow and rain continues with another 5 to 15 mm. Strong westerly winds 80 km/h with the freezing levels remaining elevated at 2000 to 2200 m.
Wednesday
Cloudy with light precipitation 1 to 2 mm. Moderate southwesterly winds 30 km/h. Freezing levels are expected to begin to descend to around 700 m near days end.
Thursday
Mostly cloudy some mid day clearing expected, very light snowfall, trace amounts. Moderate southwest winds 30 km/h. Freezing levels remain below 500 m with alpine highs of -4°C.
Friday
Overcast with very light precipitation trace amounts. Moderate southwesterly wind 30 km/h. Freezing levels are expected to remain below 500 m.
More details can be found in the Mountain Weather Forecast.
