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Avalanche Forecast

Mar 9th, 2013–Mar 10th, 2013
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
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
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
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: Sea To Sky.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain on Monday

Weather Forecast

Overnight and Sunday: Increased cloud with trace amounts of new snow / Light southwest winds / Freezing level at 1300mMonday: Moderate to locally heavy snowfall in the south of the region / Moderate to strong west winds / Freezing level at 1300mTuesday: Continued snowfall / Moderate southwest winds / Freezing level at 1100m Note: The track of Monday's system is uncertain with some weather models showing the main pulse having the greatest impact south of the border. We should have a better handle on forecast snowfall amounts on Sunday.

Avalanche Summary

In recent days a size 2.5 slab avalanche was observed above the Squamish River Valley on an east aspect at 2300m  The size of this slide suggests it may have failed on the February 20th interface. Although reports were limited at the time of publishing, there was likely a round of loose wet avalanche activity in response to warming and solar radiation on Saturday.

Snowpack Summary

Dribs and drabs of recent snowfall overlie old wind slabs in exposed areas, and spotty surface hoar or facets in sheltered locations. A sun crust exists on south facing terrain.Below the surface, last week's accumulations of 70-120cm are well settled A weakness of surface hoar and/or a crust exists near the base of last week's snow (now 1-2 m deep in some locations). Although this layer has gained significant strength, it could still be triggered in shallow rocky areas or by large triggers like a cornice fall. I would suggest using increased caution on large unsupported slopes that did not release during last week's large avalanche cycle. Below this interface, the snowpack is strong and well settled.

Avalanche Problems

Persistent Slabs

A buried layer of surface hoar or a sun crust is now down 100-200 cm. Triggering this layer has become unlikely; however, the consequences of a release would be significant.
Conditions have improved, but be mindful that deep instabilities are still present.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 6