Archived

Avalanche Forecast

Dec 10th, 2022–Dec 11th, 2022

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Glacier.

The recent low-density storm snow is settling out and showing increasing signs of slab properties. There is uncertainty that surrounds the persistent layers and when/if they will exhibit wide propagations. Assess the snowpack carefully before stepping out into committing terrain.

Confidence

Low

Avalanche Summary

Several slab avalanches up to size 2 on Saturday were observed along the highway corridor.

A loose dry cycle occurred on Friday from steep rocky terrain up to size 2.

Snowpack Summary

Up to 45cm of new snow now buries the Dec 5 layer, which consists of surface hoar, preserved stellars, facets, and a thin sun crust on steeper solar aspects.

Wind slab is likely to be found in the alpine and in open areas at treeline.

The Nov 17th Surface Hoar is now buried 60-90cm and continues to produce sudden results in snowpack tests.

Weather Summary

Snow flurries are forecasted for Sunday morning with a clearing trend by mid-afternoon as a high-pressure system settles into the region that will likely persist through the week.

Alpine temps of -10 to -6, light ridgetop winds, and a freezing level up to 1000m.

Sunny skies and light wind into next week.

Terrain and Travel Advice

Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Avalanche Problems

Persistent Slabs

The Nov 17 and Dec 5 surface hoar are down ~75cm and ~35cm respectively, and most prevalent around tree line. These layers of surface hoar continue to give 'sudden' results in snowpack tests, and produce dramatic whumpfs in previously untraveled open glades.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Wind Slabs

45cm of recent low density snow is available for transport by the moderate South winds. Watch for slab formation in the alpine and down into open areas at treeline.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2