Avalanche Forecast

Moderate - Uncertainty is due to field data and reports showing a wide variation in conditions throughout the region. Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Wednesday night: Clearing overnight, light northwest wind, alpine temperature -16 C.

Thursday: Mostly cloudy, isolated flurries with trace accumulations, light west wind, alpine high temperature -12 C. 

Friday: Cloudy, 5-15 cm of snow, strong south wind, alpine high temperature -10 C.

Saturday: Cloudy, 5-15 cm of snow, moderate southwest wind, alpine high temperature -14 C.

There have been numerous reports of large (size 2-2.5) avalanches from both natural and human triggers on a variety of aspects and elevations releasing on a surface hoar layer formed in late December. These avalanches have been breaking 60-120 cm deep. Several of them have been remote-triggered, like the one in this MIN from Wednesday.

Be sure to check out this MIN, this MIN, and this MIN for helpful illustrations of slopes that are likely to harbor this problem. A sincere thanks to the community for submitting these reports!

As the new snow settles, storm slab avalanches will remain possible trigger, and they will have the potential to step down to this deeper weak layer, forming very large and destructive avalanches.

The most recent storm delivered 15-35 cm of snow across the region with moderate to strong southwest winds. Higher accumulations fell in the southern and eastern parts of the region. Expect storm slabs to be especially touchy in lee terrain features where southwest winds have been drifting new snow into stiffer, more reactive slabs.

A very concerning layer of surface hoar from late December is now buried 60-120 cm deep. This layer formed in late December and continues to produce large avalanches across aspects and elevations. Recent snowpack tests have confirmed this weak layer's propagation potential.

• The trees are not the safe-haven they normally are at this time. Terrain at treeline is primed for human triggered avalanches.
• Be aware of the potential for large avalanches due to the presence of buried surface hoar.
• Choose simple, low-angle, well supported terrain without convexities.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.