Continued warm temps may cause cornices to fail and initiate wet loose avalanches.
Expect these larger triggers to increase the likelihood of releasing the persistent slab.
Up to 20 cm of recent snow has formed slabs in wind-loaded areas at upper elevations. These slabs have been most reactive where they overlie a crust.
Very large natural persistent slab avalanches have recently been reported, primarily on northerly aspects in the alpine.
Wet loose avalanches are likely when the snow remains unconsolidated and temperatures are warm.
On Saturday, 2 small (size 1) wind slab avalanches where reported near blue river, with one being remotely triggered from a ridge line.
In the past week, there have been several recent cornice falls triggering very large persistent slabs in this region.
NOTE: Observations in this region are currently very limited.
On the surface, up to 30 cm of recent snow exists on northerly aspects in the alpine and due to warm temperatures and elevated freezing levels is settling and becoming moist. Solar aspects continue to hold a melt freeze crust and at lower elevations on all aspects will present as moist snow.
Below this, a 5 to 25 cm variable strength crust from the late March rain event is present. This is capping a moist upper snowpack.
The primary weak layer of concern is a surface hoar, facet, and crust layer from early March, buried 60 to 120 cm deep.
The lower snowpack is generally well-settled and strong in most areas.
Sunday Night
Cloudy with light snow showers and rain 1 to 5 cm. 30 to 50 km/h southwest ridgetop wind. Treeline temperature +5 °C. Freezing level 2500 m.
Monday
Mostly cloudy with snow and rain 5 to 10 cm. 30 to 50 km/h southwest ridgetop wind. Treeline temperature +2 °C. Freezing level 1800 m.
Tuesday
Cloudy with light snow showers and rain 1 to 2 cm. 30 to 50 km/h southwest ridgetop wind. Treeline temperature +1 °C. Freezing level 1500 m.
Wednesday
Mix of sun and cloud. 30 to 50 km/h southwest ridgetop wind. Treeline temperature +1 °C. Freezing level 1500 m.
More details can be found in the Mountain Weather Forecast.
