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Avalanche Forecast

Jan 20th, 2018–Jan 21st, 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
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: South Coast Inland.

A storm system is expected to bring more snow and wind Saturday night and Sunday. Monitor how the new snow is bonding, avoid freshly wind-loaded areas and stay clear of overhead hazard.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

TONIGHT: Snow. Accumulation 10-15. Ridge wind strong, south. Temperature -5. Freezing level 800 m.SUNDAY: Snow. Accumulation 15-25 cm. Ridge wind strong, south. Temperature -3. Freezing level 1200 m.MONDAY: Flurries. Accumulation 5-10 cm. Ridge wind moderate, southwest. Temperature -5. Freezing level 1000 m.TUESDAY: Mostly cloudy, flurries. Accumulation 2-5cm. Ridge wind light, southeast. Temperature -5. Freezing level 800 m.

Avalanche Summary

Friday there were reports of natural and skier triggered avalanches (size 1-1.5) on west and northerly aspects above 1700 m failing both within the recent storm snow and up to 75 cm deep on the most recent mid-January crust.On Thursday several large (size 2-2.5) natural storm slab avalanches were observed on northerly aspects from 1200-2300 m, as well as one size 3 that was about 70 cm deep and propagated 250 m wide.Wednesday several natural and skier triggered avalanches from size 1 to 1.5 where reported at treeline and alpine elevations. Most of these were failing on the recent January 15th crust however one ski cut result was believe to have failed on the January 6th crust at 1950 m on a north aspect.

Snowpack Summary

Approximately 40-60 cm of storm snow lies above the most recent crust that was buried mid-January. This crust exists on almost all aspects and elevations with the exception of northerly aspects above 1850 m and has produced moderate to hard, sudden results in recent snowpack tests.Below this crust, a second thin crust that was buried early-January now lies 70-100 cm below the surface and has also been reactive in snowpack tests.Beneath this crust the mid and lower snowpack layers including the mid-December and late-November crust layers continue to produce hard, sudden results in snowpack tests in the northern part of the region and may still be a concern for step-down potential.

Avalanche Problems

Storm Slabs

Storm snow and strong winds will continue to build storm slabs, particulary on lee slopes at upper treeline and alpine elevations. In northern parts of the region it may still be possible for a surface release to step down to a deeper layer.
Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.Minimize overhead exposure during periods of heavy loading from new snow, wind.Avoid lee and cross-loaded terrain near ridge crests.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1.5 - 3