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Avalanche Forecast

Mar 8th, 2015–Mar 9th, 2015
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
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
1: Low
The avalanche danger rating in the alpine will be low
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

Regions: South Rockies.

Use increased caution on sun-exposed slopes during the afternoon heat. Deep weaknesses have the potential to wake-up with the strong warming.

Confidence

Fair - Due to the number of field observations

Weather Forecast

The ridge of high pressure will be the prominent feature for Monday and Tuesday before a weak coastal storm system pushes cloud into the region on Wednesday. On Monday, mainly sunny conditions are expected with freezing levels as high as 2300m. Alpine winds are expected to be moderate-to-strong from the W-NW. On Tuesday, a mix of sun and cloud is expected with freezing levels reaching around 2500m. Alpine winds are forecast to be moderate from the SW-W. On Wednesday, cloudy conditions are expected and light snowfall/rain is possible.

Avalanche Summary

On Sunday in Kananaskis Country, a skier-trigger slab released on a weak layer near the ground. On Saturday, wet sluffing was reported from steep sun exposed slopes in the Lizard range.  Similar activity is still possible on Monday as the heat and sun continues.  Human-triggering of old wind slabs also remains possible in isolated areas.

Snowpack Summary

Variable snow surface consists of wind-affected snow or wind-scoured crusts in exposed alpine areas, moist snow or sun crust on sun-exposed slopes, or 5-10cm of dry snow overlying an old crust in shady and sheltered areas. At higher elevations, ongoing winds may be continuing to build thin wind slabs in leeward features. Lower elevations are undergoing daily springtime melt-freeze cycles. The most prominent snowpack feature is a thick supportive crust 10-30cm below the surface. It extends up to around 2200m elevation. Below this elevation the crust is effectively capping the snowpack, preventing riders from stressing deeper persistent weak layers. In alpine areas where the crust is not present or is less thick, dormant persistent weak layers may still be lingering and could wake-up with heavy loading or strong warming.

Avalanche Problems

Wind Slabs

Ongoing variable winds continue to build thin wind slabs in exposed leeward terrain features at higher elevations. Afternoon sun and warming may increase the sensitivity of triggering these wind slabs.
Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2

Deep Persistent Slabs

Deeper weaknesses still exist and remain a concern in shallow rocky areas or anywhere the thick near-surface crust is weakening or non-existent, specially north aspects above 2200m.
Be aware of thin areas and rock outcroppings where it may be possible to initiate an avalanche that fails on one of the deeply buried weak layers.>

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood: Unlikely

Expected Size: 3 - 6