Archived

Avalanche Forecast

Apr 24th, 2014–Apr 25th, 2014

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

1: Low

The avalanche danger rating below treeline will be low

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Regions: South Coast.

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.

Confidence

Fair - Intensity of incoming weather systems is uncertain on Friday

Weather Forecast

Overnight and Friday: Winter continues in the mountains. Light snow overnight (5-8 cm) above 1200 metres combined with moderate Southerly winds. Mostly cloudy with light Easterly winds during the day as freezing levels climb to 1700 metres.Saturday: Good crust recovery is expected overnight as the freezing level drops down to 1100 metres. Light Southerly winds becoming moderate in the afternoon. Chance of flurries during the day.Sunday: Freezing levels dropping to 1000 metres overnight and rising to 1500 metres during the day. Expect 3-5 cm of snow during the day combined with moderate Southwest winds.

Avalanche Summary

No new avalanches reported. We are no longer receiving professional field reports from this region so public observations are really appreciated. If you are out in the mountains, please send your observations to [email protected].

Snowpack Summary

A highly variable spring snowpack exists across the region and conditions can change rapidly throughout the day. At lower elevations below-treeline, the snowpack is isothermal and melting rapidly. At mid elevations, between roughly 1500 and 2000m (and higher on sunny slopes), the snowpack is undergoing daily melt-freeze cycles. In the mornings, a refrozen surface generally means good stability. In the afternoon when the surface melts, the stability can deteriorate quickly, especially on sunny slopes. The recent storm has produced dry snow in the alpine resulting in the formation of storm slabs and wind slabs which sit on an old crust. The stability of these slabs has generally been improving but on the first really sunny day, stability is expected to deteriorate rapidly and natural avalanche activity is likely, especially on sunny slopes. Large cornices remain a concern and are expected to become reactive during periods of solar warming. The early-Feb facet/crust layer (down ~2m) and a weak basal layer are both dormant but remain a concern during periods of intense warming, especially in thinner snowpack areas, when large spring avalanches may step down to these layers.

Avalanche Problems

Wind Slabs

Another pulse of new snow and wind is expected to continue to develop new wind slabs in the alpine and at treeline. Expect winter conditions in the alpine.

Be cautious as you transition into wind affected terrain.>The new snow will require several days to settle and stabilize.>

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

Elevations: Alpine, Treeline.

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 in steep terrain. Avoid slopes with glide cracks.

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

Cornices

The added load from new snow and wind may cause cornices to fall off naturally. Cornices are more likely to release during periods of day time warming, or when there is no overnight freeze.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 4