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Avalanche Forecast

Dec 18th, 2017–Dec 19th, 2017
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
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
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: South Rockies.

Impressive snowfall amounts are forecast but avalanche danger will increase to High where more than 30 cm of snow accumulates. Cold weather after the storm should preserve the powder and provide good riding for days to come.

Confidence

High -

Weather Forecast

The storm track is set up to follow the Canada - USA border for the next few days putting the South Rockies in the bulls eye for precipitation. The region received around 10 to 15 cm overnight (by Monday morning) and the snow will start cranking up again late on Tuesday morning.Tuesday: Cloudy with snow starting to fall in the morning. Heavy snowfall in the afternoon and overnight with highest amounts south of Highway 3. Areas like Corbin, Crowsnest, and Castle Mtn should receive between 30 and 50 cm of snow. Further north around Elkford 15 to 25 cm is more realistic. Light east wind. Alpine temperatures around -10 C or colder.Wednesday: Lingering flurries but not much accumulation. Mix of sun and clouds. Light east wind. Alpine temperatures -15 to -20 C.Thursday:  Mix of sun and cloud. Dry. Light west wind. Temperatures around -15 C.

Avalanche Summary

No new avalanche activity reported.

Snowpack Summary

Up to 15 cm of new snow fell by Monday mornining. Isolated pockets of wind slab may be found on easterly aspects in the alpine, while windward slopes have been scoured down to the old rain crust or rock. Sun crusts have formed on southerly slopes.  In sheltered terrain at and below treeline very large feathery surface hoar and sugary facets are on the surface.  The two crusts that were buried near the end of November can now be found approximately 15 to 20cm below the surface. A third crust from the end of October exists near the base of the snowpack.  Recent testing on this crust did not produce significant results.

Avalanche Problems

Storm Slabs

Touchy storm slabs will develop as new snow accumulates Tuesday afternoon -- especially in the southern half of the region. Consider avoiding avalanche terrain during the height of the storm.
The new snow will require several days to settle and stabilize.Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3