Avalanche Forecast
Issued: Mar 13th, 2015 8:56AM
The alpine rating is Loose Wet, Deep Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Two pulses of precipitation are expected this weekend. The first, on Saturday, brings 5-15 mm rain with strong to gale SW winds and a freezing level near 2400 m. Late on Sunday and into Monday, it looks more hopeful for snow (10-15 cm) with the freezing level closer to 1200 m. Winds switch briefly to the NW before swinging back to the SW. Weather models are not handling the developing situation well, so I have little confidence in the specifics of the weather forecast.
Avalanche Summary
On Tuesday, our field team members in the north Elk Valley experienced several whumpfs on south facing treed terrain at 2200 m. They also experienced a whumpf of a hard slab near ridge top at 2450 m and saw a deep slab release on a sunny aspect that probably occurred some time in the last week. Recent loose wet avalanches up to size 1.5 appeared to have been triggered by solar warming. On Sunday, a skier-triggered slab released on a weak layer near the ground in Kananaskis Country. Rain, snow and wind forecast for the weekend are likely to drive natural avalanche activity.
Snowpack Summary
Rain is likely to weaken the snowpack below about 2000 m on Saturday, and may cause a natural cycle of loose wet or wet slab avalanches. At low elevations, thin snowpack areas may simply melt. On the highest peaks, new snow will probably be shifted by strong winds into slabs lee to the SW. Cornices may develop. The most prominent snowpack feature is a thick crust 10-30cm below the surface, extending up to around 2200m elevation. The support of this crust is breaking down in response to warm temperatures. Persistent weak layers below this crust still react in snowpack tests and could wake up with continued warming or loading.
Problems
Loose Wet
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 14th, 2015 2:00PM