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Avalanche Forecast

Feb 5th, 2016–Feb 6th, 2016
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
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
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: Purcells.

New snow, wind and warm temperatures are expected to make for touchy conditions. Small avalanches or cornice failures could step down to a buried persistent weak layer that has recently been responsible for large avalanches around Golden.

Confidence

Moderate - Freezing levels are uncertain on Monday

Weather Forecast

SATURDAY: Up to 10cm snow overnight, with another 5cm possible thought he day, rain expected at lower elevations, moderate to strong westerly winds, freezing level between 1200 and 1000m. SUNDAY: sunny with cloudy periods, light westerly winds, 1200m freezing level. MONDAY: sunny with cloudy periods, light westerly winds, freezing level between 2500 and 3000m, +5C at 2500m.

Avalanche Summary

We continue to receive reports of natural and skier triggered windslab avalanches from across the region. However, the January surface hoar layer remains the major concern, especially in the north Purcells where it has been responsible for several recent large avalanches. On Saturday a size 3 sledder-triggered avalanche occurred in the Gorman Creek riding area near Golden. Around the same time, a size 3.5 skier-triggered persistent slab avalanche occurred a few drainages to the south of Gorman Creek on a north-facing alpine slope. Similarly destructive persistent slabs are expected to remain possible to human triggering for the forecast period.

Snowpack Summary

Reactive wind slabs exist in the lee of ridges and open treeline features. Continued warm temperatures are expected to encourage settlement in the upper snowpack. A persistent weak layer of surface hoar and facets buried in early January is now typically down 40-90 cm. The layer is slowly getting harder to trigger in many areas, however, reports of whumpfing and some recent large to very large avalanches around Golden indicate this layer is still very much a concern, especially in the north of the region. In general, the lower snowpack below this layer is well settled and strong.

Avalanche Problems

Wind Slabs

Fresh wind slabs have formed below ridge crests and behind cross-loaded terrain features in the alpine and at treeline. Cornices have also been reported to be large and fragile and will continue to lose strength as temperatures rise.
Avoid freshly wind loaded features. >Pay attention to overhead hazards like cornices.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3

Persistent Slabs

Low probability high consequence avalanche conditions persist, especially in the Dogtooth Range near Golden. A few close calls (see Avalanche Activity) serve as a warning this layer has teath!
Be cautious around open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Be aware of the potential for remote triggers and wide propagations due to a layer of buried surface hoar and facets. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 3 - 5