Avalanche Forecast

Issued: Mar 9th, 2015 8:52AM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Wind Slabs, Loose Wet and Deep Persistent Slabs.

Peter, Avalanche Canada

South Rockies.

Sunshine and warm temperatures on Tuesday could lead to slightly higher danger ratings in the afternoon. If the snow is getting moist or wet then move to cooler, shadier slopes.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Tuesday: Mainly sunny with clouds developing late in the day. The freezing level is around 2400-2800 m. Ridge winds are light from the SW. Wednesday: Cloudy with a chance of showers or flurries. The freezing level starts near 2800 m and should lower to 2200 m. Winds are moderate from the W-SW. Thursday: A mix of sun and cloud with a slight chance of showers or flurries. The freezing level is steady at 2200 m and winds are moderate from the West.

Avalanche Summary

On Sunday, a skier-triggered slab released on a weak layer near the ground in Kananaskis Country. Otherwise there has been no new avalanche activity reported.

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.

Problems

Wind Slabs

Ongoing variable winds continue to build thin wind slabs in exposed leeward terrain at higher elevations. Afternoon sun and warming may increase the sensitivity of triggering these wind slabs.

Use ridges or ribs to avoid pockets of wind loaded snow.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Wet

Loose wet sluffs and cornice collapses remain possible with continued warm temperatures and sunshine.

Be cautious of sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely

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

Valid until: Mar 10th, 2015 2:00PM