Avalanche Forecast

Issued: Apr 24th, 2014 8:41AM

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

triley, Avalanche Canada

Northwest Inland.

Due to a lack of field observations, we are starting to transition to bulletins without Danger Ratings. Check out this Blog Post for more information on spring ratings.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain on Friday

Weather Forecast

Overnight and Friday: Expect 5-10 cm overnight as the freezing levels drop down to 700 metres and the winds become light from the East. Overcast with flurries during the day with the freezing level rising to 1500 metres. Winds becoming moderate Southeast in the evening.Saturday: Unsettled winter conditions are expected to continue. Light snow with moderate Southeast winds. Freezing levels at 800 metres overnight and rising to 1400 metres during the day.Sunday: Continued cloudy with light snow and moderate Southwest winds. Freezing level may not drop below 1000 metres overnight.

Avalanche Summary

We have a report that there are a couple of avalanche fracture lines on a South aspect of the Kathlyn glacier visible from the road. We are not sure of the size, but it is suspected that they released on a deep persistent weak layer. 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, especially during warm sunny periods.

Problems

Wind Slabs

Forecast new snow may develop new wind slabs in the alpine. Recent wind slabs have been reported to be stiff and may continue to be triggered by human activity.

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, South.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

Snow may become moist or wet during periods of day time warming. Loose wet snow may release naturally from steep terrain.

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

Deeply buried persistent weak layers continue to be a concern for isolated hard to predict avalanches. Avalanches releasing on these deep layers may be more likely during periods of strong solar radiation, or when there is no overnight freeze.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 5

Valid until: Apr 25th, 2014 2:00PM