Archived

Avalanche Forecast

Feb 1st, 2019–Feb 2nd, 2019

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

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

Regions: Little Yoho.

The avalanche hazard will rise overnight and into Saturday with additional snow and wind. Northern areas will receive the greatest amounts. Stick to more conservative lines and avoid steep overhead terrain until the new snow has a chance to bond.

Weather Forecast

Snow through Saturday with forecasts for another 10-25 cm at treeline. Northern areas will see the highest amounts. Winds remain in the moderate range with strong gusts out of the SE to SW depending on how the cold front behaves. Temperatures remain in the -5 to -15 range before plummeting Saturday night. Flurries and very cold temps on Sunday.

Snowpack Summary

15-20 cm of new snow with moderate SW-SE winds is building slabs in lee areas of the alpine. In some treeline locations a thin weak layer is found down 20-30 cm that was reactive to skiers Thursday. The mid and lower snowpack have few weaknesses in most areas, however concern remains for the weak facets below the Dec 10 interface in shallow areas.

Avalanche Summary

Local ski hills reported ski cutting small loose dry and wind slabs up to size 1.5 on Friday in steep lee areas. No reports or avalanche observations from the back-country, but we expect an increase in avalanche activity over the next 36 hrs.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Saturday

Avalanche Problems

Storm Slabs

We expect 20-40 cm of storm snow by Sunday with moderate-strong SW-SE winds. Storm slabs will form in many areas. Natural avalanches are expected in extreme terrain and human triggering will be likely in deeper storm snow or wind loaded areas.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas in the alpine and treeline. Storm snow is forming reactive slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 2

Deep Persistent Slabs

In isolated shallow snowpack areas of Little Yoho the new snow load may wake up the Dec 10th deep persistent facet weakness.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Avoid thin, rocky or unsupported slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3