No freeze is forecast overnight and light rain is expected. Warm temps, rain and no freeze may all combine to wake up the basal weakness.
Confidence
Moderate - Freezing levels are uncertain on Friday
Weather Forecast
Not much of a freeze is expected overnight and the light rain (at lower elevations) and snow above 2300m is forecast to continue overnight and through the day on Friday. Temps are forecast to climb above zero at 2500m so we may see the heat wake up some of the basal layers in areas that have not released. Ski quality will not likely be all that great on friday and it may be worth taking a pass in many areas until we get a good freeze.
Avalanche Summary
No new slab avalanche activity was observed but there were numerous loose wet slides up to sz 1.
Snowpack Summary
Rain up to 2300m on Thursday with light flurries above this elevation. There was a very minimal freeze overnight on Wednesday and as a result, the top 10-20cm of the snow is wet. Above 2300m there is a widespread crust on solar aspects up to 2600m. Northern aspects are still holding dry snow but we have certainly transitioned into the time wherein if you want dry snow, you must be on a true north aspect. The windslabs seem to be only found in isolated alpine areas but we are still getting moderate sudden collapse sheers in the basal facets down 150-180cm. Pin wheeling was observed on all aspects up to 2500m so ski quality is taking a turn for the worse.
Problems
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.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.