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

Avalanche Forecast

Dec 29th, 2018–Dec 30th, 2018
Alpine
4: High
The avalanche danger rating in the alpine will be high
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
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.

Warming temperatures, heavy snowfall with rapid loading  and moderate winds are causing storm slab formation and a  spike in avalanche danger. 

Weather Forecast

The forecast calls for 16cm more storm snow, alpine high temperature of -4C with freezing level rising to 1300m. Moderate SW winds gusting to strong will accompany the snowfall.  Cooling temperatures with clear breaks and light flurries are forecast for Sunday and Monday.

Snowpack Summary

16cm of storm snow so far. Pockets of wind slab are lingering in lee features and cross loaded slopes in the alpine and treeline. The Dec 9 and Nov 21 interfaces are down ~100-120cm and still producing Hard and Sudden test results. We have no persistent weak layers in the upper snowpack.

Avalanche Summary

Size 3 natural avalanches are running out of extreme terrain off Tupper and MacDonald this morning. Yesterday a skier went for a 40m ride on an old wind slab pocket in the Avalanche Mtn Couloir. The slide was size 1 and the skier was uninjured. The slide was 15cm deep and 30m wide and ran on an old faceted crust.

Confidence

Forecast snowfall amounts are uncertain

Avalanche Problems

Storm Slabs

Heavy snowfall, warming temperatures and moderate SW winds are working together to form fresh storm slabs. The bond to the cold, old snow surface will need time to strengthen. Expect the storm slab to be sensitive to human and natural triggering.
The new snow will require several days to settle and stabilize.Minimize overhead exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 3

Persistent Slabs

The Dec 9 and Nov 21 persistent weak layers are down ~100cm+ and consists of surface hoar, facets, or a sun crust depending on aspect and elevation.  With new rapid load these weak layers may wake up again.
If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3