Archived

Avalanche Forecast

Apr 22nd, 2018–Apr 23rd, 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

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Glacier.

Watch for an increasing avalanche danger with daytime warming and prolonged solar input. Plan to be back early afternoon to the trailhead.

Weather Forecast

A mix of sun and cloud today with an alpine high of -5C. Winds are expected to be light with occasional gusts to 35kmh. Freezing level should reach 1600m today. Alpine temperatures are expected to rise above freezing over the next few days with potentially poor overnight freeze so look for increasing avalanche danger.

Snowpack Summary

30cm+ of storm snow over the last two days and moderate S through SW winds have formed storm slabs. at and above treeline. This surface snow insulates the old moist snow surface below. Dry snow still exists on shaded aspects at high elevations. Cornices and wind loading lurk above treeline. The April 7 crust is now down 50-70cm and still a concern.

Avalanche Summary

Only one new slide recorded in the highway corridor yesterday, a size 2 in MacDonald Gulley #3. Backcountry observations were limited due to poor visibility.

Confidence

Timing or intensity of solar radiation is uncertain

Avalanche Problems

Storm Slabs

30cm of recent storm snow has formed a storm slab at and above treeline. Expect these slabs to be more reactive where wind influenced and more susceptible to human triggering as the day warms.

Watch for whumpfing, hollow sounds, and shooting cracks.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2.5

Loose Wet

Loose wet surface slides can be expected off of solar aspects as daytime warming and direct sunshine destabilize surface layers.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2.5