Avalanche Forecast
Issued: Jan 30th, 2018 5:23PM
The alpine rating is Storm Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Due to the number and quality of field observations
Weather Forecast
WEDNESDAY: Isolated flurries with trace accumulations / light to moderate west wind / alpine temperatures around -8 C.THURSDAY: Isolated flurries with trace accumulations / light to moderate west wind / alpine temperatures around -8 C.FRIDAY: Isolated flurries with accumulations of 5-10 cm / moderate west wind / alpine temperatures around -5 C.
Avalanche Summary
Large storm slab and deep persistent slab avalanches continue to be reported every day.On Tuesday, numerous large avalanches (size 2-3.5) were triggered naturally as well as with explosives. Many of the natural avalanches were triggered by cornices falling and releasing slabs on the December and November layers, producing 150-250 cm thick crowns. See the avalanche photos in this Mountain Information Network report.Similar activity over the past few weeks highlights the sustained dangerous conditions in this region.
Snowpack Summary
The most recent snowfall was accompanied with strong gusty winds, leaving touchy slabs in the alpine and large fragile cornices. Warm temperatures on Monday left moist snow and crusts up to 1700 m.About 60-80 cm of settled storm snow now covers a layer of surface hoar on sheltered aspects (especially prominent from 1400-1900 m) and sun crust on solar aspects, that was buried mid-January. Beneath the mid-January interface lie a number of very concerning buried weak layers. A layer of surface hoar from early-January is buried 90-110 cm below the surface. A weak layer buried mid-December (predominantly surface hoar and/or a sun crust) is around 120-160 cm below the surface at treeline and below treeline elevations. A rain crust with sugary facets buried late-November is near the bottom of the snowpack and is now up to 200-250 cm below the surface. All of these layers remain active and have produced recent large, destructive avalanches.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 31st, 2018 2:00PM