Avalanche Forecast

Issued: Apr 20th, 2014 8:30AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs, Loose Wet and Deep Persistent Slabs.

rbuhler, Avalanche Canada

Northwest Inland.

Avalanche danger can rise quickly with afternoon warming and solar radiation. Be aware of changing conditions and overhead hazards.For more insight into spring danger ratings, check out this blog post.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Some areas of the region may receive light precipitation on Monday while other parts may stay dry. A short period of moderate precipitation is expected late-Monday or early Tuesday. Dry, sunny conditions are expected for Wednesday. Monday: Precipitation 0-3mm, freezing level am: 1000m pm: 1500m, ridgetop wind: moderate S decreasing through the dayMon. Night: Precipitation 6-10mm, ridgetop wind: light variableTuesday: Light precipitation 1-4mm, freezing level am: 800m pm: 1500m, ridgetop wind: light variableWednesday: Mostly sunny, convective flurries possible, freezing level am: 700m pm: 1600m, ridgetop wind: light variable

Avalanche Summary

Reports from the north end of the region on Friday include sluffing from steep sun exposed slopes and isolated slab releases from leeward features on ridge crests. We are no longer receiving professional daily reports for the region so public observations are really appreciated right now. If you are out in the mountains, send your observations to forecaster@avalanche.ca

Snowpack Summary

Highly variable spring conditions are expected in the region. At lower below-treeline elevations the snowpack is typically wet and isothermal. It has not been refreezing overnight and is melting quickly. Between roughly 1000 and 1500m, the snowpack is undergoing daily melt-freeze cycles. The same conditions can be expected on sun-exposed slopes all the way to mountain-top. On higher elevation north-facing slopes, dry snow can be found. Recent strong S through W winds have scoured windward slopes and created wind slabs in leeward slopes. The early February crust/facet layer is typically down 1.5m or more. A smaller avalanche or a cornice fall may still have the potential to step down to this layer causing very large, destructive avalanches.

Problems

Wind Slabs

Recent strong S-SW winds have formed wind slabs in leeward alpine features.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.>Be cautious as you transition into wind affected terrain.>

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

Loose wet activity can be expected from steep features during periods of solar warming or rain. Isolated wet slabs may be possible under the same conditions where the recent storm snow is poorly bonded to the underlying crust.

Be cautious of sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

A deeply buried persistent weak layer still has the potential to produce very large avalanches and could be triggered by heavy triggers such as cornice falls or smaller avalanches stepping-down.

Exercise caution on steep, unsupported slopes.>Be aware of the potential for large, deep avalanches due to the presence of buried facets and surface hoar.>Conditions have improved, but be mindful that deep instabilities are still present.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 5

Valid until: Apr 21st, 2014 2:00PM