Archived

Avalanche Forecast

Apr 12th, 2021–Apr 13th, 2021

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

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

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Lizard-Flathead.

Watch for wind slabs lingering in steep open terrain and back off sun-exposed slopes when they heat up.

Confidence

High -

Weather Forecast

MONDAY NIGHT: Mostly cloudy skies, 40-60 km/h northeast wind, freezing level drop to valley bottom with treeline temperatures dropping to -8 C.

TUESDAY: Mostly sunny, 40 km/h northeast wind, freezing level to 1500 m with treeline temperatures around -2 C.

WEDNESDAY: Mostly sunny, 30 km/h northeast wind, freezing level to 1800 m with treeline temperatures around 0 C.

THURSDAY: Mostly sunny, 30 km/h northeast wind, freezing level to 2300 m with treeline temperatures reach +4 C.

Avalanche Summary

On Sunday a few size 1-1.5 human triggered slab avalanches were reported, including a storm slab on a north-facing convexity at treeline near Corbin. There was also a natural 30 cm thick slab on a steep east-facing slope in the Lizard Range and a size 1 skier triggered wet loose avalanche in a below treeline clearing.

Snowpack Summary

While sunny weather is melting the surface on southerly slopes, gusty northeast wind could blow around recent snow at upper elevations and form wind slabs on lee features. Upper elevations have 30-40 cm of settling snow from recent storm, but exact amounts are variable throughout the region due to the convective nature of the spring weather. The recent snow is sitting on hard crusts on solar aspects and a mix of wind affected or soft surfaces on shady aspects. The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack that may become a concern later this week when things really warm up.

The snow line is slowly creeping up the mountains to roughly 1400 m in elevation. Check out this MIN report for more details on the access from common staging areas.

Terrain and Travel

Be careful as you transition into wind affected terrain.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Back off slopes as the surface becomes moist or wet with rising temperatures.

Avalanche Problems

Wind Slabs

As winds shift to the northeast wind slabs may be found on all aspects at upper elevations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Cornices

Strong solar radiation and warming may trigger the large cornices that hang over ridgelines.

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 2 - 2.5

Loose Wet

Expect natural wet loose avalanches to occur on solar aspects when the sun comes out.

Aspects: East, South East, South, South West, West.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 1.5