Avalanche Forecast

Issued: Mar 30th, 2013 9:51AM

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

jlammers, Avalanche Canada

Northwest Inland.

Be alert to conditions that change with daytime warming. Danger ratings may exceed posted levels when solar radiation is strong.

Summary

Confidence

Good

Weather Forecast

Clear skies are expected on Sunday with increased cloud on Monday and a chance of light precipitation on Tuesday. Winds will be mostly light from the southwest increasing to moderate late Monday. Freezing levels may reach 2400m on Sunday, 1800m on Monday and then 1400m on Tuesday.

Avalanche Summary

Numerous loose wet avalanches have occurred from steeper solar aspects up to size 2.0. Size 2 cornice releases have also been noted. A size 2 natural slab avalanche was also reported in Morning Bowl in the Hankin area. It reportedly failed down to rocks in shallow places on a convex roll. I would expect more of this activity with forecast warming.

Snowpack Summary

Surface snow has settled with the influence of warm temperatures and surface hoar is growing on shaded slopes. Solar aspects and lower elevation terrain are now well into a daily melt-freeze cycle with sun-exposed slopes becoming very weak with daytime warming. 30 - 60 cm of snow overlies a crust, old wind slabs or surface hoar layer buried on March 9th. Reports suggest this layer is less reactive, but may still be a concern in some areas. The distribution of the surface hoar is also highly variable and it may not exist in every drainage. I would still remain conservative and continue to dig and test before diving into my line. Deeper in the snowpack, basal facets may resurface as a concern with forecast warming.Cornices have become well-developed and could easily become unstable during periods of warm weather or direct solar radiation.

Problems

Loose Wet

Clear sunny skies and warmer afternoon temperatures will promote deterioration within the upper snowpack. If surface snow becomes moist or wet, loose wet avalanches are likely.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Cornices

Large cornices will likely become weak if the sun is shining. Cornice failures may be destructive by themselves and may also initiate avalanches on the slope below.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 6

Persistent Slabs

Spotty surface hoar buried on March 9th may be reactive in some drainages. Dig down and test layers before committing to big lines. Deep weakness that formed early season may also resurface as an issue with forecast warming.

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Mar 31st, 2013 2:00PM