Northwest Mountains

The snowpack will remain generally safe provided today's storm totals don't exceed about 4".  Although it has become very unlikely, we can't rule out the potential to trigger a slab avalanche several feet thick on slopes that didn't avalanche during our previous cycle.  Guard against surprises with sound travel habits and use caution on intact slopes with variable slab thickness.  Manage for shallow new snow instabilities and facet sluffing in extreme terrain.  

A few inches of new snow today will have minimal effects on the avalanche danger.   If snowfall exceeds the forecast, stay alert for thin wind slabs forming below alpine ridges and expect the facet sluffs on shady aspects to gain a bit more volume. These issues will be small and easy to manage with defensive ski cuts but should be considered if you are in high-consequence terrain.  Increasing winds tonight and tomorrow may increase the hazard of fresh wind slabs at upper elevations, especially if the Ruby Range snow belt pulls out more than a few inches from today's snowfall.  

Almost two weeks of dry weather has allowed the snowpack to adjust from the major loading event just before Thanksgiving.  In the snow-favored Northwest Mountains, we continue to find evidence that most slopes with persistent slab structures naturally avalanched, and those that didn't are gaining strength.  This month, the lack of persistent slab avalanches or collapses in the Northwest Mountains illustrates the situation well.  However, recent propagating pit results at Irwin and Purple Ridge targeting those intact slopes are good reminders that we still have isolated persistent slab concerns.   

As you move east of Crested Butte, our limited observations demonstrate a less extensive cleanse from the natural cycle and a thinner snowpack that is somewhat slower to heal.  We've observed a few natural persistent slabs that likely ran a few days after the storm from wind drifting, and explosives or snowcats have triggered a few persistent slabs in the past week.  Although the likelihood of triggering a persistent slab is also decreasing now in the Southeast Mountains, we recommend a more cautious approach in wind-drifted terrain near and above treeline on slopes that didn't avalanche during the cycle. In most sheltered areas, the slabs have faceted away, leaving a stable snowpack except for shallow facet sluffs.    

Thank you to everyone who volunteered, supported, or attended Avalanche Awareness Night and Beacon Brushup this weekend.  We're thrilled to see such great community support and engagement!