Avalanche Forecast

Issued: Feb 11th, 2016 7:33AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Persistent Slabs.

Avalanche Canada esharp, Avalanche Canada

Avalanche conditions could vary dramatically between aspects and elevations Decision making may be more tricky than the Moderate danger rating implies. There is a chance that the forecast rain could wake up a layer of buried surface hoar at treeline.

Summary

Confidence

Low - Freezing levels are uncertain on Friday

Weather Forecast

FRIDAY: rain or wet snow, up to 15cm overnight and through the day, light southerly winds, freezing level of 2000m. SATURDAY: another 5-10cm of snow overnight, becoming scattered flurries through the day, light westerly winds, freezing level of 1500m. SUNDAY up to 15cm new snow, light westerly winds, freezing level of 1700m.

Avalanche Summary

Loose wet avalanche activity up to size 2 has been associated with the warm temperatures and strong solar radiation.

Snowpack Summary

Wet or moist snow can be found on solar aspects capped by a melt freeze crust that may break down through the day. Pockets of dry snow can still be found on high north facing slope where increasingly hard to trigger wind slabs can be found at ridge line. An older burred crust can be found down 40cm that extends well up into the alpine. Below this, a thick slab rests on a layer of surface hoar that was buried earlier in January and is now down 80-130 cm. This layer continues to pose a low probability high consequence threat, producing sudden planar fractures in snowpack tests under moderate to heavy loads. I'm going to keep it on my radar until the snowpack cools off again. A rain crust from early December sits near the base of the snowpack.

Problems

Storm Slabs

An icon showing Storm Slabs
The forecast rain and/or snow will make for variable conditions. Small fresh wind slabs are expected to form through the day in the alpine.  Freezing levels are uncertain, if rain falls on dry snow (high north aspects) expect reactive slabs.
Avoid avalanche terrain during periods of rain.>Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>Be alert to conditions that change with elevation.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
I'm still concerned about the layer of surface hoar buried back in January.  Could the forecast storm be the straw that breaks the camels back? I'm not sure! Given this uncertainty I would avoid open features around treeline tomorrow.
Be aware of the potential for large avalanches due to the presence of buried surface hoar. >

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

3 - 5

Valid until: Feb 12th, 2016 2:00PM

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