Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
View on map

Avalanche danger

Fri
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

A frozen snow surface and increasing clouds should result in generally safe avalanche conditions Thursday. Even still you may encounter a few signs of unstable snow. You could see rollerballs or maybe even small wet slides in steep sun-exposed terrain.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1

    We think a decent overnight freeze, increasing clouds, and cool northerly winds should limit the sun’s impact on the snow surface Thursday. However, you may still see isolated areas become wet and unstable. This will be most likely around steep rocky slopes where the sun can have the greatest impact. Don’t be surprised if you see rollerballs or a few small loose wet slides. Make sure to take these avalanches into account if you plan to travel in higher consequence terrain like above cliffs or open creeks. 

    With another warm day on tap, you could continue to see the snow shed from trees and rocks. This may include the rare cornice crashing down. Even though large looming cornices aren’t as prevalent as we often see, you don’t want to be under one if it fails. Look for routes that help you limit the time you need to spend below these waves of snow.

    (1/19/2023)

    Example: A Wet Loose avalanche occurred as a result of a tree bomb during a period of sunshine on 1/19. [S 5200']

    Photo: Zack Novak

Avalanche Discussion

Clear skies and a long mid-winter night should help the snow surface freeze despite warmer temperatures. As a result, the sun will need to break down this surface crust before you see any meaningful avalanches. By the time the sun really gets up in the sky, increasing clouds and strengthening winds should help curtail any major warming. But, we hope you notice this avalanche forecast hinges on the weather. A weaker overnight freeze, fewer clouds, or lighter winds could all result in widespread unstable wet snow and higher avalanche danger. If you see lots of rollerballs or wet slides growing larger, then the scales have tipped. Dial it back and seek out slopes that aren't basking in the sun. 

After two warmer days, we expect any lingering wind slabs to be very hard to trigger. That doesn’t mean they aren’t out there. You could find a pocket of wind-loaded snow near the tops of the higher peaks in steep unsupported or convex terrain. Even though we aren’t calling this out as a more widespread problem, keep it on your mind before you travel onto rocky consequential slopes. 

We’re mainly talking about very shallow snowpack instabilities. While you can find older interfaces and crust in the top few feet of snow, we haven’t seen any recent slides on these layers. In most locations, 1.5-2ft (45-60cm) sits over the very stout and prominent MLK crust. On shaded slopes, this is often capped by a very thin breakable crust from mist/rain/fog on Tuesday. If you dig you may find older interfaces (sometimes marked by weak melt-freeze crust on sunny slopes) 6-8in (1/21 int) and 12-15in (1/18 int) below the surface. We aren’t concerned about avalanches failing below the MLK crust at this time.

Regions covered