Archived

Avalanche Forecast

Mar 10th, 2018–Mar 11th, 2018

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

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

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: Glacier.

We experienced a significant natural avalanche cycle yesterday. Expect the strong effects of the sun today to destabilize the snowpack again.

Weather Forecast

A strong upper ridge of high pressure is building over much of the province bringing sunny skies and warm temperatures. In our region we will see freezing levels at 1600m, an alpine high of -4 deg C and light ridge top wind. This warming trend will continue with freezing levels forecast to reach 2700m by mid week.

Snowpack Summary

20cm of storm snow has fallen in the last 48hrs, this came in with strong, gusting extreme Southerly winds. Above freezing temps at valley bottom will have created a surface crust below ~1500m. A crust buried 60cm is present on steep solar aspects. Deep PWLs are dormant and buried over 1.5m. Cornices have seen new significant growth.

Avalanche Summary

Yesterday we experienced a significant natural avalanche cycle at Roger's Pass due to heavy snowfall and strong winds. Over 50 avalanches were observed, the largest were sz 3.5s and many ran to the full extent of their runouts. Expect another avalanche cycle again today with warm temps forecast and strong solar radiation.

Confidence

Timing or intensity of solar radiation is uncertain

Avalanche Problems

Wind Slabs

Strong south winds and recent storm snow have created wind slabs. Expect these slabs to be most reactive at ridgetop or in steep unsupported terrain. Today is forecast to be sunny and the strong solar radiation to make the windslab more reactive.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2.5

Persistent Slabs

Sun crusts are buried 30-60 cm on steep solar aspects. This interface provides a smooth bed surface and may contribute to larger than expected avalanches. It is possible for smaller avalanches to trigger this lingering problem.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3

Loose Wet

Today the new snow will get a blast of strong spring solar radiation. This should trigger a natural cycle of loose wet avalanches on solar aspects, most likely initiated from rock outcrops or dropping snow pillows.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 2