A fast-moving and turbulent overnight storm has increased the avalanche danger for new snow avalanche problems. Fresh wind slab avalanches have now become the primary avalanche problem. While in wind-sheltered terrain, backcountry riders could encounter loose snow avalanches in steep terrain and the remote possibility of small storm slabs in the new snow. Use your eyes to look around and further take time to investigate the new snow before pushing into steep avalanche terrain today.
Overnight southwesterly winds were gusting into the 80's at 12,000ft, and averaging 10-20mph at 11,000ft. Fresh wind slabs have formed on the lee sides of ridgelines and cross-loaded terrain features. Most of these slabs are expected to be small in size. At below treeline elevations, wind slabs will have a more isolated distribution and are generally located to some cross-loaded terrain features.
Hard slabs that break 2 to 6 feet deep on weak layers near the ground remain a low likelihood concern. The problem has become increasingly stubborn and isolated, and it has been several weeks since we have observed a persistent slab avalanche. There is lingering uncertainty that skiers or riders can trigger a large avalanche from the margins of the slab where it thins out, especially at higher elevations. Cornice falls can also trigger large avalanches. You can reduce your risk by traveling where the snowpack is deeper and more uniform. Regroup in safe zones that are clear of unusually wide and long-running avalanches.
An example of a thick, hard persistent slab that released naturally in mid-February.
Well, that was an exciting morning as this storm has continued to increase snow totals, while gusty winds further blow that new snow about. From 4:30am to 5am, an additional 2 inches of new snow accumulated on the CBMR Pow Cam. That's just one example of the more intense pulses of snow over the last 10 hours or so. The early am snow totals look to be about 4 to 7" in the Norwest Mountains, and 3 to 6" in the Southeast Mountains. Those numbers should increase a couple of inches this morning until snowfall tapers for the better part of Wednesday.
Below treeline elevations don't have a well-defined primary avalanche problem at the moment. Backcountry travelers should instead evaluate the new snow and avalanche terrain carefully for a variety of potential small and isolated avalanche problems. These would include isolated wind slabs, loose snow avalanches, and the potential for shallow storm slabs.
The avalanche danger is forecasted to see little change heading into tomorrow. However, there is snow forecasted for each 12 hr period headed towards the weekend. If snow accumulations Wednesday Night exceed the expected forecast, then upper elevations could start approaching CONSIDERABLE danger as early as Thursday. Otherwise, the next bump in the avalanche danger will probably come later in the week.
