A recent size 3 avalanche on Friday on Ha Ling reminds us that destructive spring time avalanches are possible. Stability will decrease throughout the day as temps warm up, especially if the sun comes out so use caution.
Confidence
Good - Freezing levels are uncertain on Saturday
Weather Forecast
An upper trough is being pushed into the forecast region by a high pressure ridge in BC and as a result, we will see some isolated flurries throughout the day on Saturday. Precipitation amounts will likely only be 5-10cm but this precip should fall as snow and not as rain.
Avalanche Summary
1 size 3 avalanche on a NE aspect on Ha Ling. Slide was 1000m long with a fracture width of 300m. Depths of the crown were variable from 1.5m to 60cm. Slide ran full path taking out mature timber. Numerous loose wet slides were observed below 2000m due to the recent rain. Two loose wet slides covered the closed section of HWY 742 below the EEOR overnight. Observations were limited in the southern part of the forecast region due to limited visibility.
Snowpack Summary
An isothermal snow pack can now be found at lower elevations. New snow that fell over the past 24hrs was rapidly settling into a soft slab due to the mild temperatures.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.