Persistent instabilities are still a concern - avoid areas where the snowpack thins and manage large slopes at treeline conservatively.
Avalanche danger is decreasing, make sure to evaluate conditions as you travel.
Recent strong winds from the SW through NW have formed wind slabs in exposed terrain at higher elevations. These slabs are more reactive where they overlie buried surface hoar or a smooth crust.
10-40 cm of settling snow sits over the January 30 surface hoar and crust layer. This layer has produced large natural and human triggered avalanches last week. The mid January crust/facet layer is buried 50-70 cm and could be triggered in shallow snow pack areas or by a large load such as a cornice or step down avalanche.
A cooling trend lowers freezing levels this week and a weak front brings light snowfall on Monday.
SUNDAY NIGHT: Cloudy with freezing levels dropping to 500m. Moderate southwest winds.
MONDAY: Cloudy with light snowfall delivering 5cm over the day. Strong southwest winds. Freezing levels reach 1200m. Alpine high of -2.
TUESDAY: 5-10cm possible snowfall overnight into Tuesday morning. A mix of sun and cloud with light westerly winds. Chance of flurries. Freezing levels reach 1200m. Alpine high of -3.
WEDNESDAY: A mix of sun and cloudy with light westerly winds. Freezing levels reach 1500m, alpine high of -1.
A large persistent slab avalanche was reported in the Steeples on Saturday afternoon, on a south facing aspect at 2300 m. This avalanche had wide propagation and ran 2 km in length and is believed to have occurred on the late January persistent weak layer, crowns were estimated at 50 cm deep.
A recent MIN reported a human triggered size 1 persistent slab avalanche on the same layer on a south aspect at treeline.
Several natural and human triggered wind slab avalanches to size 2 have been reported this week, on north through east facing slopes.
Exposed terrain at alpine and treeline elevations hold dense wind effected surfaces with large cornices from westerly winds. Sheltered areas and lower elevations hold a widespread melt freeze crust.
The late January interface is buried 15-40cm deep, and consists of a melt-freeze crust at lower elevations and on solar aspects extending into the alpine. Surface hoar sits above the crust in sheltered areas at treeline and below.
The widespread January 18 rain crust is now around 40-100cm deep with weak faceted snow above. It is most prominent in the Lizard range. In heavily wind scoured areas at treeline and above this crust may even be found on the surface.
The snowpack below is well consolidated, with the early-December crust/facet persistent weak layer buried 100-200 cm deep. It is currently considered dormant. We expect this layer to become active later this season, check out the forecaster blog for more information.
