Snoqualmie Pass

You're unlikely to trigger an avalanche on Wednesday, but if the sun makes an appearance, anticipate small loose avalanches off rocks and cliff bands. If it starts to turn warm and sunny out, limit your time directly underneath large cliff bands and rocky features.

Snoqualmie Pass picked up another inch or two of low-density snow Monday night into Tuesday. Cloud cover persisted, with very brief periods of clearing, keeping the recent snow relatively cold and dry, especially on shaded and northerly aspects. Southerly aspects have developed a crust near the surface due to Monday's sun. Wind speeds trended downward through the day, from moderate to light across the Pass.

Forecasters made a trip to the north slope of Chair Peak on Tuesday to further investigate two buried weak layers: the 2/7 interface, composed of preserved surface hoar, and the 2/13 interface, made up of surface hoar and faceted grains. Both layers were identified, though the 2/13 layer was faint and took some digging to find. Neither layer showed significant instability in Extended Column Tests. That being said, the existence and distribution of these layers warrant continued attention as more snow stacks up. Currently, 8–10 inches of low-density snow rests above the 2/13 interface, with about 5 inches between it and the deeper 2/7 layer. As we continue to add more snow on top, it is unclear whether these layers will produce avalanches or slowly settle into a non-issue.

Wednesday should bring similar weather to Tuesday, but with an increase in snowfall. Within the current weather pattern, there's greater uncertainty regarding the timing of snow and how much will fall. There may be greater variance than usual between drainages. Cloud cover may fluctuate across the Pass as well. If it starts to feel warm and bright out, anticipate an increase in small, wet loose avalanche activity. If you start seeing fresh roller balls, trees shedding, or small natural releases, consider moving to shadier aspects.