Archived

Avalanche Forecast

Apr 15th, 2014–Apr 16th, 2014

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

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

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.

A weak overnight freeze coupled with April showers will destabilize surface crusts at lower elevations.

Weather Forecast

A weak system rolls through Rogers Pass today/tonight, bringing light precipitation (less than 5cm), light to moderate westerly winds, and freezing levels around 1500m. Tomorrow will see a gradual clearing before the next disturbance on Thursday.

Snowpack Summary

Temperatures did not reach the freezing mark in the alpine until 1-2am, likely preventing a solid freeze of the surface. With light rain on the way, expect the crust to break down earlier in day. The snowpack on solar aspects is warming to near isothermal levels, but it stills awaits a dramatic warming to lose its structural integrity.

Avalanche Summary

Despite the warm alpine temperatures yesterday, only a small cycle of loose moist avalanches to size 2.0 on solar aspects was observed.

Confidence

Avalanche Problems

Loose Wet

Low elevation areas are relying on a good overnight freeze to keep the snowpack together. There was not a strong freeze last night, so expect the surface crust to break down with light rain and the occasional glimpse of strong April sunshine.

Start and finish early before the surface crusts melt.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Wind Slabs

Thin, variable slab is present in the alpine and tree-line. It appears to be bonding with the underlying interface, but some pockets in lee features may surprise a person.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2

Persistent Slabs

Deeper persistent layers will require a large trigger to initiate, or a couple of people hitting a thin, weak spot in the snowpack.

Pay attention to overhead hazards like cornices.Be aware of the potential for full depth avalanches due to deeply buried weak layers.

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

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 4