Tuesday's danger hinges on the snow line. Rain is expected all the way to treeline, so you'll need to increase the rating by one step if you encounter more than 20 cm of new snow at treeline.
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
Tuesday: Periods of rain and wet snow bringing around 60mm to lower elevations and 50-60 cm of new snow to high alpine elevations. Strong southwest winds. Freezing level to 1700 metres with alpine temperatures around 0 to -1. Wednesday: 15mm of rain below about 800 metres, with around 15 cm of new snow above. Moderate southwest winds. Freezing level to 1200 metres with alpine temperatures of -1. Thursday: Flurries bringing 10 cm of new snow. Moderate southwest winds. Freezing level to 900 metres with alpine temperatures of around -2.
Avalanche Summary
No new avalanches have been reported, but it should be noted that the warm, stormy weather has been discouraging some backcountry travel and obscuring visibility into alpine terrain.Looking forward, the primary hazard will exist where new snow is accumulating instead of rain. This will become increasingly relevant as you reach upper treeline elevations or if you are exposed to alpine slopes overhead. As rain continues to fall, ongoing potential also exists for loose wet avalanche activity, especially on steeper slopes. Ongoing rain and snow at higher elevations will also maintain the risk of large avalanches releasing over the late February interface. Large, open terrain features and avalanche paths should be avoided while this potential exists.
Snowpack Summary
Heavy rain has saturated the upper snowpack at all but high alpine elevations after roughly 50mm of precipitation fell over Sunday night and Monday morning. Any new snow that may have accumulated at high alpine elevations is likely to remain reactive to human triggering over the short term. At higher elevations, lingering potential may exist for loading from rain or snow to promote reactivity at the late February interface, roughly 1.5 metres deep. This layer is composed of a sun crust on southerly aspects and surface hoar on shaded aspects. An avalanche on this layer would be large and very destructive. No concerns exist below this interface and the snowpack at treeline and below is generally well settled and strong.
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.
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.
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.