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Avalanche Forecast

Mar 15th, 2016–Mar 16th, 2016
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
2: Moderate
The avalanche danger rating in the alpine will be moderate
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
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: Sea To Sky.

Lingering storm slabs and cornices are expected to become weak with sun exposure and afternoon warming.  Use extra caution on sun exposed slopes when the solar radiation is strong.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Unsettled conditions are expected for Wednesday as a ridge of high pressure builds over the coast. Cloudy conditions with light flurries are expected for the morning and a mix of sun and cloud is expected for the afternoon. Afternoon freezing levels are expected to be around 1300m and alpine winds are forecast to be moderate from the northwest. Sunny conditions are expected for Thursday with afternoon freezing levels around 1500m and light to moderate outflow winds. A mix of sun and cloud is forecast for Friday with freezing levels climbing as high as 2500m and moderate southerly winds in the alpine.

Avalanche Summary

On Monday, a natural cornice fall triggered a size 1.5 storm slab on a northeast aspect at 2000m. Another size 2 cornice release was reported but it did not trigger a slab. A skier triggered a size 1 storm slab on a convex wind loaded feature which was 20-50cm thick. Another skier remotely triggered a size 1.5 storm slab from 10m away on a southeast aspect at 1800m elevation which was 35cm thick. Explosives triggered several cornices size 2-3. Natural and artificially triggered avalanche activity up to size 2.5 was reported from across the region over the weekend. If the sun comes out on Wednesday, cornices and lingering slabs are expected to become weak, and could even fail naturally.  Loose sluffing is expected from steep sun exposed slopes.

Snowpack Summary

Up to 120cm of snow fell over the last week.  This snow is reported to be settling and gaining strength, but lingering storm instabilities may still exist, especially in recently wind loaded terrain features.  Cornices are reported to be large and fragile. Isolated sun crusts can already be found on steep sun exposed slopes, with widespread sun crust formation expected in the next couple days.  The mid and lower snowpack are generally strong and well-settled.

Avalanche Problems

Storm Slabs

Lingering storm slabs may remain reactive to human-triggering, especially in wind loaded areas. Sun and afternoon warming may increase the reactivity of these slabs.
The new snow may require several days to settle and stabilize. >Be cautious as you transition into wind affected terrain. >Minimize exposure to sun exposed slopes when the solar radiation is strong. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4

Cornices

Cornices are reported to be large and weak. Natural cornice releases are possible with sun exposure and warming.
Give cornices a wide berth when travelling on or below ridges.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 5

Loose Dry

Loose sluffing is expected from steep sun exposed slopes when the solar radiation is strong.
Be cautious of sluffing in steep terrain.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3