Avalanche Forecast

Issued: Feb 16th, 2016 7:53AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs, Cornices and Loose Wet.

pmarshall, Avalanche Canada

South Rockies.

Warm temperatures on Wednesday will keep avalanche danger elevated. If you're seeking good snow you'll have to head up high, but be cautious with freshly wind-loaded slopes and overhanging cornices.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Wednesday: Mainly cloudy with light snow or rain - 5-10 mm/cm. The freezing level peaks somewhere near 2000-2200 m. Ridge wind are light gusting to moderate. Thursday: A chance of flurries early then mainly sunny. The freezing level is around 1800 m and ridge winds are moderate from the SW. Friday: Mainly sunny. The freezing level is around 1800 m and winds remain moderate from the SW.

Avalanche Summary

No new slab avalanches have been reported in the past few days. Small loose dry and loose wet sluffs were observed in the Crowsnest Pass area on Tuesday. There was also evidence of recent natural cornice failures.

Snowpack Summary

Up to 30 cm of recent storm snow sits on a melt-freeze crust on southerly aspects and lower elevation terrain, surface hoar on sheltered slopes, and older wind affected surfaces in exposed terrain. Widespread wind effect is evident in the alpine with fresh wind slabs forming in exposed lee terrain. Cornices have grown significantly recently. Expect moist snow or a thin sun crust on solar aspects depending on the time of day. A layer of buried surface hoar can be found between 50 and 70cm down and remains a concern, primarily west of the Continental Divide. Below 1500-1600 m the snowpack is essentially isothermal and very spring-like. The snowpack rests on a weak crust/facet layer from early December.

Problems

Wind Slabs

Steady southwesterly winds have create dense wind slabs in lee and cross-loaded terrain near ridge crests. Forecast warm temperatures could make these more sensitive to human triggering.

Be careful with wind loaded pockets on steep slopes below ridge crests.>Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Cornices

Cornices should continue to grow with mild temperatures, steady ridge winds, and light snowfalls. They could fail naturally or under light loads.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Loose Wet

Warm temperatures and possible light rain below treeline could trigger loose wet sluffs in steep terrain and confined gullies.

Be cautious of sluffing in steep terrain at lower elevations if it's raining.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 17th, 2016 2:00PM