Avalanche Forecast
Issued: Mar 5th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
ahanna,
Avalanche Canada
Recent storm slabs likely remain sensitive to rider triggers, especially in wind loaded terrain features and where recent snow sits over a slippery crust. Take a conservative approach, ease into terrain cautiously and watch for signs of instability.
Summary
Confidence
Moderate
Avalanche Summary
Over the weekend, control work using explosives and ski cutting produced size 1-1.5 storm slabs at treeline. Loose dry avalanches up to size 2 were observed at various elevations on Thursday.
A slew of MINs from the Mt Cain area last weekend reported several rider triggered storm/wind slab avalanches up to size 2. We suspect they were running on a recently buried crust.
If you head into the backcountry please consider sharing your observations on the Mountain Information Network!
Snowpack Summary
Small increments of new snow continue to accumulate. 30-60 cm of recent snow sits in an upside-down configuration, with warmer, heavier snow on top of colder, lower density snow. At upper elevations, the recent snow has likely seen some redistribution into lee terrain features by moderate wind.
A thick, widespread crust formed in mid February now sits 50-90 cm deep. Near Mt Cain, the crust is glassy with faceted crystals sitting on top of it, which makes for a poor bond to the overlying slab of snow. For more details, check out this reel from our field team! Elsewhere the crust seems to be bonding well. You can check the bond in your local area by performing a simple hand shear test on an isolated block.
The mid and lower snowpack is well consolidated, containing a series of well-bonded crusts.
Weather Summary
A persistent low whirls in place offshore of Washington, producing light flurries over Vancouver Island for the next few days. Freezing levels will hover around 800 m.
Sunday night
5-10 cm of new snow. Light southeast wind. Alpine low -3 ºC.
Monday
5-10 cm of new snow. Moderate southeast wind. Alpine high -2 ºC.
Tuesday
5-10 cm of new snow overnight then a mix of sun and cloud. Moderate southeast wind. Alpine high -2 ºC.
Wednesday
Flurries with sunny breaks. 5-10 cm of new snow . Strong southeast wind. Alpine high -2 ºC.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
- Start on smaller terrain features and gather information before committing to bigger terrain.
- Be carefull around freshly wind loaded features.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Problems
Storm Slabs
Recent storm slabs may remain reactive to rider triggers, especially in wind loaded terrain features at upper elevations.
On the north island, there may remain potential for slabs to fail down to a buried crust, 50-80 cm deep, propagate widely and run surprisingly far.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 6th, 2023 4:00PM
