Avalanche Forecast
Regions: Glacier.
There is a lot of variability in the snowpack right now.
Be sure to evaluate each slope with fresh eyes.
Confidence
Moderate
Avalanche Summary
On Saturday, a skier triggered a size 1.5 storm slab in the start zone of Frequent Flyer where the debris almost hit the skin track.
Thurs' storm triggered a few natural avalanches in the hwy corridor, up to sz 2.5. Avalanche control Thursday produced widespread results, triggering avalanches up to sz 3.0.
Before Thursdays snowfall, large avalanche debris and fracture lines could be seen in most avalanche paths from last weekends storm which produced up to sz 4 avalanches.
Snowpack Summary
Up to 40cm of new snow has fallen since the big storm March 8/9. This new snow has been redistributed by strong SW winds. The March 5th interface exists down 50-100cm as a crust &/or surface hoar (3-10mm, largest in the alpine).
Two persistent weak layers (PWL) of heavily facetted snow from cold temps in Jan/Feb are now buried 120-190cm deep.
Weather Summary
Unsettled atmospheric conditions mean convective weather until the ridge sets up on Tuesday.
Tonight Isolated flurries. Alpine low -11°C. SW wind 20km/hr. Freezing Level (FZL) 600m.
Mon Cloudy, isolated flurries. High -9°C. West wind 20-30km/hr. FZL 1200m.
Tues Mix of sun/cloud, isolated flurries. Low -14°C, High -10 °C. W wind 20km/hr. FZL 800m.
Wed Sun/ cloud. Alpine high -8°C. Wind SW-25km/h. FZL 1200m.
Terrain and Travel Advice
- Avoid areas with a thin or variable snowpack.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Avalanche Problems
Storm Slabs
New snow this past week, along with moderate to strong SW winds, have created a storm slab. This slab will be most reactive where stiffened by the wind or warmed by the sun.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2.5
Persistent Slabs
A persistent weak layer (PWL) was buried March 5th and is now down 50-100cm in the snowpack. Depending on aspect and elevation, this layer may be suncrust, facets and/or surface hoar. There's potential for step-down avalanches to this layer if storm slabs in motion trigger them.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5