Archived

Avalanche Forecast

Jan 14th, 2017–Jan 15th, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

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

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

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

Regions: South Coast Inland.

Wind slabs are slowly gaining strength but you can expect those on south aspects to become touchy with any solar radiation (especially in the south - Coquihalla region).

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

We're in a warming trend with no precipitation expected on Sunday. Big change on Monday through Wednesday, stay tuned. SUNDAY: Increasing clouds in the afternoon. Winds light - moderate westerly. Freezing level rising to 600m in the south and alpine high temperatures around -3 Celsius. MONDAY: Snow beginning near noon. Winds moderate to strong from the southwest. Alpine high temperatures to -4 Celsius. TUESDAY: 15-20 cm snow. Winds moderate gusting strong (40-60 Km/hr) from the southwest. Alpine temperatures around -1 Celsius.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

The main story is widespread variability due to all the shifting wind patterns, distributing and redistributing snow over the past few weeks. 25-30cm of low density snow fell over Sunday and Monday in the southern (Coquihalla) area, while northern sections received 7-15cms of new snow. During the storm, moderate southwesterly winds distributed the new snow onto north and east aspects, forming reactive soft slabs. After the storm, winds shifted to classic outflow (northerly) patterns on Tuesday with moderate winds at ridge top. This pattern resulted in 'reverse loading' of wind slabs onto southerly slopes as far down as 1850m in the north (Duffey Lake zone) and 1700m in the south (Coquihalla area). These new, old and variable wind slabs are the primary weaknesses of concern in the snowpack. The older wind slabs from a week ago (on south to west aspects) remain a concern in our current snowpack with recent cold temperatures having slowed their healing into the snowpack.

Avalanche Problems

Wind Slabs

Wind slabs have formed on a wide range of aspects through the combination of a southwesterly storm flow and subsequent northerly outflow winds. Tune in to patterns of wind loading as you travel and be especially cautious of thin trigger points.

Carefully evaluate steep lines for wind slabs.Watch for areas of hard wind slab in steep alpine features.Choose well supported terrain and avoid convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2