Lawinenlagebericht

Snoqualmie Pass

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Wed
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
3 · Erheblich
Open full map
Veraltet — dieser Lagebericht ist 3 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

On Tuesday, you’ll need to manage wet and dry avalanche problems at Snoqualmie Pass. Their likelihood and sensitivity may fluctuate throughout the day to match the weather. Wet avalanches may occur naturally, while dry slides will be primed for human-triggering. 

Lawinenprobleme

  • Storm Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2

    An upside-down snowpack has developed at Snoqualmie Pass and was responsible for multiple small avalanches on Monday. That trend should continue as snow accumulates Monday night and Tuesday morning. Use handpits or small test slopes as you travel to look at all of the snow over the 1/20 interface. You’re looking for heavy snow over weaker snow, sensitive interstorm layers, or a poor bond at the 1/20. Slabs were reactive on convex features and unsupported slopes on Monday. You should be suspect of any slope over 35 degrees on Tuesday.

    (1/22/2024)

    A skier triggered storm slab avalanche on a convex slope. Multiple parties reported similar avalanches, even in forested terrain.

    Photo: William Sirski

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Temperatures should continue to hover right around 32 degrees at the Pass proper. A slight waver in the temperature or the loss of east flow can change the precipitation type. Wet avalanches already started to fail on Monday afternoon as temperatures spiked, but we didn’t get the full rain on snow event expected (again!). Lower elevations are primed for significant wet avalanche activity when and if this happens. Loose wet should be the most common, but don’t rule out a few slabs. Activity could peak overnight or during the morning hours. So keep an eye on the sky and take note of new rollerballs, fan-shaped avalanche debris, or snow shedding from trees and rocks. Whenever it starts to happen, seek out lower-angled terrain and keep aware of slopes above you.

    (1/22/2024)

    Wet loose avalanches occurred at lower elevations as temperatures spiked. These ran across the PCT, a popular winter travel route for snowshoers and backcountry skiers.

Avalanche Discussion

The Pass is an amazing place. We don’t know how it held onto snow for so long with temps over 32 degrees, but Old Man Winter isn’t going down without a fight. That said, he is old and showing signs of weakness. The early stages of a wet avalanche cycle was observed at lower elevations on Tuesday. Wet Loose, a few slabs, and roofalanches were spotted on the Alpental road as NWAC forecasters exited the field. Driving down the west side, wet activity became more prominent, and it was full-on rain by Denny Creek.

Numerous avalanche professionals had the same observations as NWAC forecasters. The 1/20 transitions from merely a storm interface down low into a stout freezing rain crust as you ascend in elevation. This interface was the failure point for multiple small storm slab avalanches - both natural and human-triggered. The storm snow also changed in moisture content but was upside-down in most locations. Hand pit results varied across the terrain from stubborn to failing on isolation.

Deeper in the snowpack, we still have a poor structure focused around the Solstice Crust. We continue to watch this layer with concern but have not had a suspected avalanche on it since 1/10. Above it, other interfaces, such as the 1/8 and 1/16, have produced test results and are suspected to have been the failure point for a few avalanches over the weekend. Weak facets were identified at the 1/16 late last week.

Abgedeckte Regionen