Avalanche Forecast

Moderate - Uncertainty is due to the limited number of field observations.

A noticeable shift in the weather pattern, as warm temperatures embrace the region with light amounts of snowfall throughout the week. Snow, wind, and freezing levels will vary greatly across the region. Be sure to check your local forecasts and assess conditions as you travel.

Monday Night: Intermittent cloud. 0-5 cm of snow expected. Strong to Extreme southwest winds, becoming moderate to strong by the morning. Freezing levels up to 500 m. 

Tuesday: Overcast. 0-10 cm of snow expected. Moderate to extreme southwest wind. Freezing level rising to between 500 and 1500 m.

Wednesday: Mostly cloudy. 0-10 cm of snow expected overnight, and up to 7 cm more through the day. Strong to extreme west winds trending to moderate through the day. Freezing levels between 500 and 1500 m.

Thursday: Partly cloudy. 0-5 cm of snow overnight, and a possible trace through the day. Moderate to strong wind, variable southwest through northwest. Freezing levels falling to between valley bottom and 500 m 

Our North Rockies field team got out to Hasler on Sunday, and they saw a small avalanche on a wind loaded slope just below a ridgeline, and saw other signs of instability. Check out their MIN report here for more details and a report on snow conditions.

 

There are very few reporting operations in this region, so remember that a lack of observed avalanches does not necessarily mean that there is a lack of avalanche activity. If you are getting out in the backcountry, and have conditions information, or even just good vibes and good photos to share, consider making a post on the Mountain Information Network (MIN).

Since Sunday, variable snowfall has added 10-35 cm of new snow to the top of the snowpack, and light snowfall is forecasted to continue on Monday. Strong southwest winds will continue to redeposit this snow into wind slabs in lee areas in the alpine and treeline. 

This recent snow overlies a previously wind-effected surface comprised of old hard wind slabs, sastrugi, and areas stripped back to the ground or old crusts. Near-surface faceting above the old surface may increase the reactivity of newly formed storm or wind slabs, especially as the temperature rises through the week.

A crust that was formed at treeline elevations and below in early December has been reported in parts of this region. It can be found down 50-100 cm. There have been no recent reports of avalanches on this layer. While the layer is now dormant in the region, a large amount of new snow or warming temperatures have the potential to wake it up, and wind slab avalanches may still have the potential to step down to this layer in isolated areas. 

The base of the snowpack is composed of crusts and weak faceted grains, particularly in thin snowpack areas east of the divide. 

• Start with conservative lines and watch for clues of instability.
• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
• Avoid exposure to slopes that have cornices overhead.