Lawinenlagebericht

West Slopes North

Northwest Avalanche Center
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Lawinengefahr

Sat
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Kernpunkte

Several avalanches occurred on Thursday, and with more snow through Friday expect avalanches to continue. Avalanches are most likely to occur in areas where wind deposited the snow into heavier, thicker drifts, however, it may not be easy to identify those thicker deposits. Stick to lower angle slopes unless you're able to assess the top 3 feet of snow for weaknesses with a snow pit, and use small test slopes before getting out onto larger, steep terrain. 

Lawinenprobleme

  • Wind Slabs

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

    One small natural wind slab avalanche was reported on Thursday, and several human triggered avalanches were reported. Some avalanches are failing as deep as the Solstice Crust, buried at the start of our current storm on 12/21. Telemetry at Heather Meadows at Mt Baker Ski Area reported two feet of snow burying that crust.  Wind slabs could grow to several feet deep over the crust on Friday, and avalanches are likely with a human trigger. 

    Cooler temperatures, subtle winds, and a growing layer of concern mean that this light, fluffy snow could pose more of a challenge for identifying wind slabs.  Your usual clues such as identifying textured snow or pillows, or seeing shooting cracks may not be as obvious. Unless you are sure you're off wind loaded slopes, digging down to just under the solstice crust in a snowpit and  completing stability tests in representative terrain are your best bet at identifying the problem.  Get out onto small test slopes before exposing yourself to large steep slopes. If you aren't experienced with testing for instabilities with these methods sticking to slopes less than 35 degrees is a good call on Friday. We've got excellent low density snow right now, and travel on lower angle terrain will still make for a good time. 

    (12/23/2021)

    A small skier triggered wind slab avalanche occurred in the Baker backcountry on Thursday 12/23. This failed above the Solstice Crust on a small, steep convexity on a SE aspect at 6000ft.

    Photo: Matt Lubar- Baker Mtn Guides

  • Storm Slabs

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

    Storm slab avalanches in non wind-loaded terrain are possible on Friday. This is especially the case in areas where the snow is not well bonded to the Solstice Crust. You might find this slab up to 2 feet thick.  Quickly investigate the new snow layer hardness and how well it is bonded to the solstice crust to determine whether avalanches might occur in the new snow layer. Use small test slopes before you expose yourself to large steep slopes. 

    This storm is bringing in cold dry snow, so small dry loose avalanches are expected in the surface layer. You could trigger a small loose avalanche as you enter a steep slope, or as you make your way down it. They will probably remain small in size, but remain alert for them if you travel in steep terrain. Most importantly, don't send one down onto another person beneath you. 

    Even small storm slab avalanches present a danger when combined with terrain traps.

    Photo: Lee Lazzara

Avalanche Discussion

We are currently amidst several days of unsettled weather which began Tuesday night.  We're going to keep getting snow at least through Christmas day.  Small and large avalanches are occurring in new layers of snow we're received since Tuesday, amounting to almost 4 inches of water or two feet of snow at Heather Meadows as of Thursday evening. As snow continues to slowly add up, avalanches will gradually increase in size as well. 

We've received several reports of a "right side up" snowpack in non wind-affected areas. The "right side up" snowpack is usually attributed to cooling temperatures during the storm. Heavier snow with warmer temperatures falls earlier and then temperatures cool, with snow becoming lighter and fluffier usually contributing to more stable avalanche conditions. Oftentimes this circumstance makes travel easier as well, where there is lighter snow at the surface to move through upon a heavier base beneath. 

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