Regions
South Coast Inland.
A wet and wild winter storm system with heavy snow, strong winds and mild temperatures is increasing the avalanche hazard. Travel in avalanche terrain is not recommend until the new snow has had a chance to settle and bond to the old surface.
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
TONIGHT: Snow. Accumulation 15-25 cm. Ridge wind extreme, southwest. Temperature near 0. Freezing level lowering to 1300 m.THURSDAY: Snow. Accumulation 10-20 cm. Ridge wind strong, southwest. Temperature -2. Freezing level 1300 m.FRIDAY: Cloudy, flurries. Accumulation 2-8 cm. Ridge wind moderate, southwest. Temperature -2. Freezing level 1000 m.SATURDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind moderate southwest. Temperature -2. Freezing level 1000 m.
Avalanche Summary
Reports from Tuesday indicate that the new snow had formed thin wind slabs that were reactive to skier triggers but had little mass or consequence. Expect this to change as new snow amounts accumulate with the approaching storm.On Sunday there was a report of a skier triggered size 2.5 slab avalanche in the northern part of the region that initiated as a 30 cm thick wind slab then stepped down to approximately 70 cm thick (likely the mid December layer) on a north-east aspect at 2050 m.
Snowpack Summary
A new snow (up to 25 cm in the northern areas and about 5 cm in southern parts) has buried the most recent, January 15th crust. This crust exists on almost all aspects and elevations with the exception of northerly aspects above 1850 m where the snow surface remained dry during the alpine inversion event on the weekend.Below the January 15th crust about 30-50 cm of snow overlies a 1 cm thick crust that was buried on January 6th which exists up to about 2000m. Mid and lower snowpack layers including the mid December and late November crust layers have produced moderate to hard, sudden results in snowpack tests in the northern part of the region last week and may be a concern for step-down potential.
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.