Avalanche Forecast

Moderate - Timing or intensity of solar radiation is uncertain

Continued snowfall is expected Saturday night as an unstable air mass fuels convective precipitation. A ridge is expected to build offshore Sunday allowing the entire province to dry out. A more spring-like pattern begins to take shape on Monday with freezing levels creeping towards 2000 m by Tuesday.SATURDAY NIGHT: Overcast, freezing level around 500 m, light to moderate west/southwest wind, 4 to 10 cm of snow possible. SUNDAY: Overcast, freezing level beginning near valley bottom rising to about 2000 m, light to moderate northwest wind, 1 to 2 cm of snow possible. MONDAY: Scattered cloud cover, freezing level beginning around 1000 m rising to about 2100 m, light west/southwest wind, no significant precipitation expected. TUESDAY: Scattered cloud cover, freezing level holding around 2000 m, moderate to strong southerly wind, trace of precipitation possible.

Only small loose dry avalanches (sluffing) to size 1 were reported from east facing aspects around treeline on Friday.Reported avalanche activity on Thursday was limited to a size 2 natural cornice failure on a southeast facing slope at 2900 m. On Wednesday a natural size 3 cornice failure was observed on an unknown aspect, the cornice did not initiate any other avalanche activity. Small loose dry sluffing was also observed on south facing aspects between 1500 and 2100 m suggesting that the cool temperatures are preserving cold snow, even on southerly aspects.

Warming temperatures and time have helped to settle the upper snowpack and have likely formed a weak surface crust on all aspects below about 1800 m. This crust likely extends higher on south facing slopes. On north facing slopes above 2000 m, temperatures have remained cold and the snowpack is still quite "winter-like."The main concern is the mid-March Persistent Weak Layer (PWL), which is now 60 to 100 cm below the surface. This layer is composed of a crust on all aspects at low elevations. At upper elevations the layer presents as a crust on solar aspects (those that face south and west) and buried surface hoar on polar aspects (those that face north and east). The reactivity of this interface has been steadily decreasing and while the likelihood of triggering a deeper persistent slab avalanche is lowering, the consequence of doing so remains high. Solar aspects are expected to be the most suspect as the freezing level begins to rise over the next few days.Deeper persistent weak layers from January and December are still being reported by professional observers, but are generally considered dormant.