Avalanche forecast

Hatcher Pass

Hatcher Pass Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

The avalanche danger is MODERATE for WIND SLAB avalanches.

Hatcher Pass received little snow and strong winds during the Jan 6/7th storm. This radically transformed the landscape and our snowpack and built thick, hard wind slabs. 

Today, moderate gusting strong winds will be capable of building new wind slabs.

It will be possible to find and human trigger wind slab avalanches up to 2.5' deep in specific leeward terrain 30° and steeper. Natural avalanches are unlikely. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Moderate gusting strong winds out of the ENE today will be capable of transporting the modest amount of new snow we have available from 1/6-7 on the surface at upper elevations. Be on the lookout for active signs of wind loading, such as pluming and drifting snow along ridgetops. Watch for signs of instability such as whumphing and shooting cracks as you travel. It will be possible to trigger new, shallow wind slabs that form throughout the morning today. 

    Thicker and more stubborn wind slabs from the 1/6-1/7 storm will remain possible to trigger with higher consequences. The last storm event was more wind than snow. The relatively protected Independence Mine SNOTEL site registered winds 30-38mph for 12+ hours. Hatch and Marmot AT 4500' registered wind gusts 90mph+. While winds tapered and several inches of light, new storm snow can be found over a variety of surfaces, these extreme winds built stout, harder wind slabs up to 2.5' thick. 

    You will be able to find these in specific leeward terrain throughout the forecast area and are most likely to trigger in steep terrain below ridges, in gullies and below rocks where extreme winds built thicker slabs over preserved facets. Be observant of crossloaded features (see photo of Hatch Peak Sunnyside below) and terrain traps. 

    This week's wind slabs are sitting over weak, sugary faceted snow grains at various layers of the snowpack. At the deepest, they could fail on basal facets sitting on top of ice at the bottom of the snowpack. Due to the thickness of these slabs and the "upside down" nature of this new structure, this problem is likely to persist for a while. 

    You are less likely to experience shooting cracks with these stiff slabs with this problem as it trends stubborn and harder to trigger. Pay attention to firm, hollow feeling or sounding surfaces. Spot your partners, travel one at a time through steep or complex terrain and ski from zones of safety to zones of safety. 

     

     

    Avalanche triggered on Marmot on Tuesday, 3550' 

    HS-AOu-D1-O

    Photo: Allie Barker

Avalanche Discussion

RECENT AVALANCHES:

Several small, natural mid-storm wind slab avalanches in Hatcher Pass from the 1/6-1/7 storm are observable below ridgelines on 4068' and Marmot. 

Forecasters were able to easily trigger two small wind slab avalanches on Tuesday 1/7 when conditions remained touchy as the storm tapered.

On Wednesday 1/8, a skier reported a small skier-triggered avalanche on the sunnyside of Skyscraper. Another party reported a small  human-triggered slab avalanche on Government Peak that propagated 100'. Very few recreators were observed in Hatcher Pass and we saw minimal feedback on our new snowpack structure following the significant wind event. 

Regions covered