Avalanche Forecast

Issued: Mar 13th, 2014 9:35AM

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

bcorrigan, Avalanche Canada

South Rockies.

Sun drenched slopes will have a higher danger rating than sheltered north aspects. For more insight into the current tricky conditions, see the most recent:Forecasters Blog.

Summary

Confidence

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

Weather Forecast

Synopsis: The ridge of high pressure begins to breakdown with the coming Pacific frontal system. Snow in the forecast !Tonight: Clear periods, no precipitation in the forecast, freezing level around 1300 metres. ridge top winds moderate from the west, occasionally gusting to strong.Friday: Cloudy with sunny periods, 5 to 10cm of precipitation, freezing level around 1800 metres, winds from the southwest , light to moderate, occasionally gusting to strong.Saturday: Cloudy with flurries, freezing level around 1600 metres, ridge top winds moderate to strong from the south west.Sunday: Cloudy with precipitation, 10 to 20cm possible, freezing level around1800 metres.

Avalanche Summary

No reports of avalanches in the forecast region from yesterday. Cornices have gotten large and mature and may trigger large destructive avalanches if they fail. There have been two reports recently where human triggered avalanches were initiated from roads below clear-cuts and ran full path with destructive consequences.

Snowpack Summary

Night time cooling will help to stabilize the snowpack when there's a good freeze, but recently freezing levels have been above the valley bottom in most parts of the forecast area, leaving us with a water-saturated snow pack between valley bottom and 1600 metres in some places. When the surface crust beaks down with daytime heating any disturbance could trigger a wet dense avalanche on this type of snow. Above 1600m the previously mentioned weak layers still exist, especially on north aspects. The weak layers buried in this years snow pack are not going away soon, and may not go away until the seasons snow has completely melted, especially on north aspects.

Problems

Storm Slabs

Rising freezing levels and solar input are major concerns right now. Wet surface snow avalanches may create a big enough load to trigger the weak layers buried deep in the snow pack. North slopes still have touchy storm slabs over weak layers.

Caution required around loaded road banks, cutblocks and other non obvious avalanche terrain>Avoid freshly wind loaded features.>Avoid exposure to sun exposed slopes.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Wet Slabs

Incoming storms are likely to be rain below 1800 metres, further adding to the water saturation in the lower elevations snow-pack. Daytime heating and nighttime cooling are a critical part of the daily hazard evaluation.

Avoid steep unsupported terrain below treeline especially if the snow is moist or wet.>Assess start zones carefully and use safe travel techniques.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

Consider the consequences of the terrain if an avalanche steps down to a persistent weakness.>Use conservative route selection, resist venturing out into complex terrain even if you observe no obvious signs of unstable snow.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Mar 14th, 2014 2:00PM