Avalanche Forecast

Issued: Apr 12th, 2012 10:40AM

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

jlammers, Avalanche Canada

Northwest Inland.

Summary

Confidence

Poor - Due to limited field observations

Weather Forecast

Friday: light snowfall continuing overnight into early Saturday morning / light to moderate northwesterly winds / freezing level at 1300m Saturday: mainly cloudy skies with possible clearing in the afternoon / light and variable winds / freezing level at 1200m Sunday: light snowfall / light southwest winds / freezing level at 1400m

Avalanche Summary

No new avalanches were reported from this region.

Snowpack Summary

We have had very little information about the snowpack in this region for several days now. However, I suspect the light snowfall with light winds at higher elevations has created a fairly consistent covering over a variety of old surfaces. These surfaces include well settled powder on steep north-facing slopes, and temperature-affected snow on solar aspects up high and on all aspects at lower elevations. I suspect below the snow line, rain is penetrating and weakening already wet snow. As we head deeper into spring, expect potentially potent, yet relatively short-lived, instabilities with each storm. Wet slabs and wet loose snow avalanches also remain a real possibility during periods of warming or direct solar radiation, especially if there is minimal amounts of overnight freeze. Expect cornices to be large and potentially unstable, especially under sunny skies.

Problems

Wind Slabs

Forecast new snow and wind may create fresh wind slabs on lee slopes.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

Snow stability can deteriorate very quickly with spring temperatures. Watch for loose wet avalanches on steep terrain, especially if the sun is shining.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Cornices

Large cornices exist in alpine terrain. A failure could be destructive by itself, and could also trigger an avalanche on the slope below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Apr 13th, 2012 9:00AM