Avalanche Forecast

High - We have a good understanding of the snowpack structure and confidence in the weather forecast

The forecast is marked by a nice diurnal temperature swing with the freezing level rising to around 1500 m during the day and then returning to valley bottom at night which is all well and good. Things change Friday night when the freezing level is expected to go to 2500 m (ish). Get the cold snow while you can.

MONDAY NIGHT: Freezing level at valley bottom, light variable wind, trace of snow possible.

TUESDAY: Scattered cloud cover, freezing level starting at valley bottom rising to about 1500 m, light southwest wind at lower elevations, moderate to strong northwest wind at ridge top, no significant snowfall expected.

WEDNESDAY: Scattered cloud cover, freezing level starting at valley bottom rising to about 1500 m, light southwest wind at lower elevations, moderate to strong northwest wind at ridge top, no precipitation expected.

THURSDAY: A few clouds, freezing level starting at valley bottom rising to about 2000 m, light to moderate west wind at lower elevations, strong northwest wind at ridge top, no precipitation expected.

Widespread natural and intentionally human triggered avalanche activity to size 2 was reported from all aspects Monday. One of the wind slabs was up to 45 cm deep in places. The bulk of the activity was above 1750 m which suggests that the low elevation surface hoar really hasn't hit its tipping point yet, or that there just isn't that much surface hoar. Regardless, wind loaded features near ridge line appear to be the problematic features.

Sunday's storm produced 15 to 25 cm of storm snow which now rests on a variety of old surfaces including a firm crust on solar aspects, soft faceted snow and surface hoar in sheltered areas, and old wind slabs near ridge crest. The new snow has been formed into variable wind slabs in exposed terrain features, especially those near ridge crest.

A thick rain crust sits 30-60 cm below the surface and can be found up to 2100 m. Avalanche activity was last observed at the faceting interface between this crust and overlying snow on February 17.  

The mid-pack is well settled and strong, but the base of the snowpack contains basal facets that are most prominent in shallow rocky start zones.

• Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.