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Avalanche Forecast

Mar 10th, 2014–Mar 11th, 2014
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: South Rockies.

Warming temperatures and Solar radiation will play a leading role in the avalanche hazard in the coming days. Pay special attention to large ripe cornices !

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Synopsis: The Pineapple express that plowed its way across the province in the last few days has moved south and east leaving us with a high pressure ridge for the next few days.Tonight: Cloudy with light to locally moderate precipitation, freezing level should drop to valley bottom. ridge top winds light to moderate from the north west.Tuesday: Mix of sun and clouds, no precipitation in the forecast, light to moderate winds at ridge tops, freezing level climbs to 1500m, and possibly above.Wednesday: Sunny with cloudy periods, no precipitation in the forecast, freezing level rising to 1800m. winds from the south west, light to moderate.Thursday:  Sunny with cloudy periods, possibility of flurries, freezing level rising to 1800m. Light ridge top winds.

Avalanche Summary

There was a report that the Morrisey slidepaths near Fernie ran to nearly full path on Sunday. Also on Sunday, near neighbors in the Lizard Range report storm slabs and loose wet avalanches to size 2.5.There is concern for an ongoing natural and human triggered avalanche cycle on Monday with more snow in the south, and solar radiation hitting the slopes when we get some blue skies. Cornices have gotten large and tender and may trigger slabs if they fail.Avalanches in the region have the potential to run full path as dryer storm slabs from the alpine entrain moist snow as they descend. Avalanches in clearcuts, road banks, lower angle terrain and non obvious avalanche paths continue to surprise backcountry enthusiasts throughout the region, so consider them carefully in your travel plans through the forecast period.

Snowpack Summary

Storm slabs continue to build on top of the March 2nd weak layer which consists of facets, surface hoar and/or crusts, depending on your elevation and aspect. There is now 70-100cm of snow on this layer in the deeper snow-pack zones in the south of our region (Flathead and around Fernie).The mid pack contains the February 10th persistent weak layer, which in some of the deeper snowpack regions, could be up to 2 meters deep. In the shallower snow packs it is likely about a meter deep, and is becoming a more isolated problem, and probably could only be triggered by a large load, a cornice failure or storm a slab in motion.  Be aware of slopes that have not yet not run on the February 10th layer... but those areas are getting harder to find.In the lower elevations (below 1600m) in the south of the region, expect the snowpack to be rain soaked and loosing cohesion. Below tree line the snow pack is most likely close to isothermal in rain affected areas, and at least moist everywhere else.

Avalanche Problems

Storm Slabs

Rising freezing levels and solar radiation for the first time since the last storm may trigger storm slabs or cornice failures. New snow and continued warm temperatures will add to the storm slab problem in the south of the region.
The new snow will require several days to settle and stabilize.>Avoid freshly wind loaded features.>Caution required around loaded road banks, cutblocks and other non obvious avalanche terrain>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very 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

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 3 - 6