Avalanche Forecast

Issued: Mar 11th, 2014 9:36AM

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

bcorrigan, Avalanche Canada

South Rockies.

Rain soaked and moist upper elevation snow packs may take a while to cool off and stabilize. Pay close attention to daytime heating and mature cornices. For more information on the tricky conditions see the latest:South Rockies Blog

Summary

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

Synopsis: A upper level ridge is building over the interior of BC and will bring clear skies and warm spring-like conditions for the next few days.Tonight: Clear periods, freezing level will drop to valley bottom. ridge top winds light from the west.Wednesday: Sunny with cloudy periods, no precipitation in the forecast, freezing level rising to 1800m. winds from the west, light to moderate.Thursday: Sunny with cloudy periods, possibility of flurries, freezing level rising to 1700m. Light ridge top winds.Friday: Cloudy with sunny periods, trace of precipitation, freezing level around 1800 metres, winds from the southwest , light to moderate, gusting to strong.

Avalanche Summary

Numerous reports of large wet avalanches in the forecast area, some running full path beyond their historical run-out zone. Cornices have gotten large and ripe and may trigger large destructive avalanches if they fail.Avalanches in clear-cuts, road banks, lower angle terrain, and non obvious avalanche paths continue to surprise back country enthusiasts throughout the region, so consider them carefully in your travel plans through the forecast period.

Snowpack Summary

Night time cooling will help to stabilize the tricky conditions as the storm slab settles and gains strength. Daytime heating will again put the weak layers up for action as the snowpack adjusts to the warming and cooling, especially the weak layer closest to the surface from March 2nd. Any activity on this layer may create a big enough load to trigger the lower weak layers with the possibility of a very large destructive avalanche. Slopes gaining heat from the strong spring sun should be highly suspect, and treated with respect and caution. 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 aspectsIn the lower elevations (below 1600m) in the south of the region, expect the snowpack to be rain soaked and losing cohesion. Below tree line the snow pack is most likely close to isothermal in rain affected areas, and at least moist everywhere else.

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.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Wet Slabs

Wet slabs are a concern on slopes with rain soaked snow now sitting over weak layers. Wet loose avalanches are also expected where rain soaked snow has lost its cohesion. Warm temperatures and solar radiation will contribute to the hazard.

Avoid steep unsupported terrain below treeline especially if the snow is moist or wet.>

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 12th, 2014 2:00PM