Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Login
Archived

Avalanche Forecast

Mar 21st, 2023–Mar 22nd, 2023
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
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
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

Lingering wind slabs may remain reactive to human triggers on northerly aspects in the alpine.

Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.

Confidence

High

Avalanche Summary

Two naturally triggered large (size 2-2.5) deep persistent slabs were reported on northerly aspects in the alpine on Monday. One was triggered by a cornice fall in the Renshaw zone and the other occurred in the Premier range.

Numerous naturally triggered wet loose avalanches up to size 2.5 were reported on sunny aspects in the alpine.

Snowpack Summary

Expect to find a melt-freeze crust on the surface of all aspects at treeline and below and on sunny aspects in the alpine. Solar radiation will break down the crust on sunny slopes throughout the day.

Lingering wind slabs may remain reactive to human triggers on northerly aspects in the alpine.

20-30 cm down there is a sun crust on sunny aspects and surface hoar (3-10 mm) on isolated shady and sheltered slopes.

The mid-snowpack is generally strong but the lower snowpack is a different story..

The November facets are still prominent at the base of the snowpack. They are showing signs of improving but this layer remains a significant concern in rocky, shallow, or thin to thick snowpack areas at treeline and above.

Weather Summary

Tuesday Night

Clear skies / 10 km/h southwest ridgetop wind / Temperature at treeline around -10 C / Freezing level valley bottom

Wednesday

Sunny / 20 km/h southwest ridgetop wind / Temperature at treeline around -3 C / Freezing level 1800 m

Thursday

Mostly sunny / 20 km/h south ridgetop wind / Temperature at treeline around -4 C / Freezing level 1700 m

Friday

Mostly cloudy with isolated flurries; 0-3 cm / 10 km/h southwest ridgetop wind / Temperature at treeline around -7 C / Freezing level 1300 m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Cornice failure may trigger large avalanches.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Avalanche Problems

Wind Slabs

Lingering wind slabs may remain reactive to human triggers on northerly aspects in the alpine.

Aspects: North, North East, North West.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2

Loose Wet

Strong solar radiation will increase the likelihood of wet loose avalanches on sunny aspects in the alpine.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2

Deep Persistent Slabs

A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2.5 - 4