Avalanche Forecast

Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Wednesday: Sunny with some cloudy periods. Ridgetop winds 15-25/h km from the south and alpine temperatures + 8 degrees. Freezing levels 3500 m.

Thursday: A mix of sun and cloud. Ridgetop winds 10-20 km/hr from the southwest and alpine temperatures near + 4 degrees. Freezing levels 3000 m.

Friday: A mix of sun and cloud. Ridgetop winds 15-30 km/hr from the southwest and alpine temperatures + 5 degrees. Freezing levels 3000 m.

On Tuesday, a large size 3 natural avalanche was observed on a NE aspect at 2400 m. It was reported as a cornice failure triggering the slope below and appeared to have slid on the early November crust near the base of the snowpack.

On Wednesday, we may see more of these deeper releases with the warm up as well as smaller natural avalanches becoming especially reactive where recent snow sits over a crust or surface hoar. Loose wet avalanches are also likely. 

Our eyes and ears in the mountains are limited at this time of year and may continue this winter due to fewer professional observations. If you see anything (or don't) while out in the field, please consider sharing via the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!

10-20 cm of recent snow has been wind loaded into lee features in exposed areas at upper elevations and may sit over a thin melt-freeze crust on south aspects and possibly surface hoar in wind-sheltered areas around treeline. Forecast sun and rising freezing levels into the alpine will have the greatest impact on the upper snowpack, showing signs of instability.

The lower snowpack is characterized by a few crusts formed during warm periods over the last month. 

• In the north, treeline snowpack depth sits around 80 to 120 cm. The crust of note here is sitting near the base of the snowpack, likely surrounded by a weak layer of sugary facets. Snowpack tests and recent avalanche activity suggest that this layer could be triggered by humans and produce large avalanches.

• In the south of the region, the snow line has been reported around 700 m near Hope and treeline snowpack depth sits around 100-150 cm. The deeper crusts in this area are generally well bonded to surrounding snow.

• The likelihood of deep persistent slab avalanches will increase with each day of warm weather.
• Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
• Avoid steep slopes when air temperatures are warm, or solar radiation is strong.