New snow combined with reactive, persistent weak layers is creating dangerous conditions
Stick to low-angle slopes and avoid exposing yourself to steep terrain from above
Be aware of the potential for remote-triggering and large avalanches due to buried surface hoar, especially at treeline and below.
Up to 20 cm of recent snow and wind may have formed reactive storm slabs. These slabs will be most reactive in lee areas by ridgetops, and could step-down to deeper weak layers.
On Tuesday, several size 1 to 1.5 persistent slabs were triggered by skiers across the region, and whumpfing was reported in many areas.
Over the weekend and through Monday, many large, persistent avalanches were triggered by people, including remotely. Some failed naturally.
Check out these MIN reports for some examples:
Mar 1 MIN: A very close call
Feb 28 MIN: A fatal accident occurred involving two sledders.
Feb 27 MIN: Remote triggered from 50 m away
5 to 20 cm of new snow from Wednesday, fell as rain below approx 1500 m. Up to 10 cm more may fall in the northern parts of the region on Thursday. Areas that received enough new snow have reactive new storm slabs, which in some cases are resting on a new surface hoar layer. In most areas, the snow is overlying a crust except for shady high-elevation terrain, where the crust is absent.
In the top 100 cm of the snowpack, there are multiple concerning persistent weak layers of surface hoar and/or facets/crusts. The majority of the recent large and destructive avalanches occurred on well-preserved surface hoar in sheltered areas at treeline and below.
The remaining snowpack has no current layers of concern.
Wednesday Night
Mostly cloudy. 0 to 2 cm of snow. 30 km/h northwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1700 m.
Thursday
Mostly cloudy. 0 to 10 cm of snow. Highest amounts for the northern regions. 30 km/h northwest ridgetop wind. Treeline temperature -5 °C. Freezing level 1600 m.
Friday
Mix of sun and clouds. 30 km/h west ridgetop wind. Treeline temperature -2 °C. Freezing level 1800 m.
Saturday
Mix of sun and clouds. 1 to 8 mm of precipitation as snow or rain at treeline. 50 km/h west ridgetop wind. Treeline temperature 2 °C. Freezing level 2500 m.
More details can be found in the Mountain Weather Forecast.
