Avalanche Forecast
Regions: Glacier.
Natural avalanches are possible today, and if triggered could be large enough to reach valley bottoms. Today is a good day to minimize exposure to overhead avalanche terrain.
Weather Forecast
A fast moving low pressure center passing our area today will give strong SW winds, up to 15cm of snow (mostly falling this evening), and rising temperatures (freezing level of 1100m, but a treeline high of -6).
Another similar system passes Tuesday evening giving strong winds, rising temps and up to 15cm of snow. On Wednesday we get a brief break.
Snowpack Summary
Strong gusting Extreme SW winds are building fresh windslabs in all open terrain. The February 22nd persistent weak layer is now buried down 60+cm, and consists of 3-7mm surface hoar on all aspects up to 2450m, and a crust on solar aspects. No other layers are currently active in the mid and lower snowpack.
Avalanche Summary
Numerous reports of skier and remotely triggered large persistent slab avalanches (on the Feb 22nd layer) this weekend.
Avalanche control Saturday morning produced numerous large to very large avalanches (up to size 3.5) in the highway corridor.
Several natural avalanches occurred Friday night. Large avalanches (up to size 3) ran to valley bottom.
Confidence
Intensity of incoming weather systems is uncertain
Avalanche Problems
Persistent Slabs
Surface hoar buried on February 22nd is now a persistent weak layer down 60+cm. The surface hoar overlies a thick crust on solar aspects. This layer was active yesterday and remains susceptible to human triggering.
- Minimize exposure to steep, planar slopes.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3.5
Wind Slabs
Strong- Extreme winds this morning are building fresh windslabs in all open terrain. The wind slabs, where triggered, could step down to the Feb 22nd surface hoar layer.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Be cautious as you transition into wind affected terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2