Archived

Avalanche Forecast

Mar 3rd, 2016–Mar 4th, 2016

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

4: High

The avalanche danger rating in the alpine will be high

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Glacier.

It's getting deep out there, but as the storm snow settles into a slab expect it to get touchier. Be especially cautious where the new snow overlies a crust, if triggered avalanches will run far and fast on that bed surface.

Weather Forecast

Unsettled weather will continue for the outlook. Today and tomorrow expect scattered flurries, with 5-10cm a day, freezing levels rising up to ~1600m, and light but gusty SW winds. Saturday another significant pulse will bring up to 20cm of snow with strong winds and freezing levels rising to ~1800m.

Snowpack Summary

Incremental precipitation has brought ~50cm of snow over the past 4 days. Sustained moderate S'ly winds will have further loaded lees and formed soft slabs. The storm snow has buried Feb 27 layer, which is a variable crust on SE-W aspects, widespread surface hoar/stellars on shaded aspects, and in some areas a combination of both.

Avalanche Summary

Numerous size 2-2.5 avalanches from steep avalanche paths with start zones that are loaded by S'ly winds were observed yesterday. A few small avalanches on S'ly aspects were likely triggered by the warming temps causing trees to drop "tree-bombs". In the region loose and slab avalanches have been easily triggered by people, including some remotely.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Avalanche Problems

Storm Slabs

~50cm of snow is settling into a soft slab and sits on a crust on solar aspects and surface hoar. If triggered it will likely run far & fast especially with the crust as a bed surface. Expect it to sluff easily in areas where it hasn't formed a slab.

Use caution on open slopes and convex rolls Ski short pitches and regroup in safe spots.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 3

Wind Slabs

There is lots of new snow available for the sustained S'ly winds to transport. Lee slopes will have deep wind-loaded pockets that may be easily triggered, and if they are have the potential to entrain significant mass with the reactive storm slab.

Use caution in lee areas. Recent wind loading has created wind slabs.Give cornices a wide berth when traveling on ridges.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3