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

Avalanche Forecast

Feb 22nd, 2021–Feb 23rd, 2021
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
4: High
The avalanche danger rating below treeline will be high
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
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

Regions: Glacier.

Our winter wonderland was walloped by a warm, wet, and windy wild one.

A natural avalanche cycle is occurring in the Rogers Pass area, with numerous large avalanches from size 3 to 4.

I highly recommend you visit your local ski hill today.

Weather Forecast

Passage of the main storm front this morning, then unsettled afterwards.

Today: Cloudy with locally intense flurries, 5-10cm, FZL 1500m, Alp high -5*C, mod/gusting extreme S winds

Tues: Cloudy with flurries, trace amounts, FZL 600m, Alp high -12*C, mod W winds

Wed: Cloudy with sun and flurries, Alp high -12*C, mod SW winds

Snowpack Summary

Extreme south winds and a warm 40mm of precip overnight. The Feb 14 drought interface is now down 50-70cm in sheltered areas; this interface is predominantly a wind crust in exposed areas near the height of the pass, and buried windslabs and facets as you move East and West. Facets and a weak suncrust still linger down 80-100cm on the Jan 24th PWL.

Avalanche Summary

We are in the tail-end of a natural avalanche cycle, with large (up to sz 4), naturally-occurring avalanches running in many paths. Observations from the overnight shoot include numerous sz 3-4 artillery-controlled avalanches both east and west of the Pass. Natural activity should drop with the passage of the front and cooling later this morning.

Confidence

Avalanche Problems

Storm Slabs

60+cm of storm snow is being redistributed by strong/extreme S'ly winds. This lies over the Valentine's Day weak interface of facets, crusts and variable wind effect. Slab properties have developed and are failing on this layer.

  • Avoid exposure to avalanche terrain, large avalanches may reach the end of run out zones.
  • If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 1.5 - 4

Persistent Slabs

The Jan 24th interface has been found in numerous recent profiles. This layer has awakened with increased load from the storm. It is most concerning on steep, unsupported terrain features on solar aspects, where it exists as a sun crust.

  • Persistent slabs may be more sensitive to human triggering on solar asp where it sits on sun crust
  • If triggered the persistent slab may step down to deeper layers resulting in large avalanches.

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2 - 4