Warm temperature and sunshine will destabilize the snowpack throughout the day, especially on steep slopes that are baking in the sun. Timing, thoughtful terrain choices and conservative decision-making are essential for safe travel in the backcountry.
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.
Warm temperatures may cause cornices to become weak. Cornice failures are dangerous on their own, but also have the potential to trigger larger avalanches on the slopes below.
Wtih minimal overnight cooling forecasted, the surface snow may not solidly refreeze at lower elevations. 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.
A frontal wave draped across southern B.C. will keep the southeast regions mostly dry for Sunday.
SATURDAY NIGHT: Partly cloudy. No precipitation. 10-20 km/h southwesterly winds. Low alpine temperature -3 C with freezing level around 2000 m.
SUNDAY: A mix of sun and cloud. No precipitation. 10-15 km/h southwesterly winds. High alpine temperature +7 C with freezing level around 2700 m.
MONDAY: A mix of sun and cloud with isolated flurries. Trace of precipitation. High alpine temperature +5 C with freezing level around 2300 m.
TUESDAY: A mix of sun and cloud with isolated flurries. Trace of precipitation. High alpine temperature +3 C with freezing level around 1200 m.
On Friday, a wind slab avalanche was triggered by a skier on a steep north facing slope in the alpine. Numerous cornice falls (up to size 2.5) both natural and explosive-triggered were reported on northerly aspects in the alpine. Several wet loose avalanches up to size 2 were observed on solar aspects.
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. At very low elevations, the snowpack may be wet and isothermal, depending on overnight freezing levels.
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.
The lower snowpack is generally strong and well bonded.
