Lawinenlagebericht

West Slopes North

Northwest Avalanche Center
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Lawinengefahr

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

It was unusual to see that the weather station at Mt Baker received less snow and water than nearly every other weather station in the West North zone, and danger likely didn't reach high there, although we received reports of much more snow and natural avalanches from the south side of Baker. The storm isn't quite over yet, and models are showing nearly an inch of water coming in with strong winds overnight, before the precipitation slows down and winds decrease Tuesday. Especially earlier in the day, and depending on where you are in the zone, human-triggered slab avalanches could still be likely, so steer around steep slopes near and above treeline at least until you've thoroughly tested smaller slopes first. 

Lawinenprobleme

  • Storm Slabs

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

    Avalanche danger is expected to peak overnight with the storm's last intense burst of snow before wind and precipitation slow down during the day. Steep slopes will probably be most reactive to a human trigger earlier in the day.  More reactive slopes will likely be thicker and stiffer wind slab deposits, however, if you're in a location where there's well over 6 inches of new storm snow any steep slopes may avalanche with a human trigger. Taking into account the timing and amounts of snowfall, wind, and overnight cooling temperatures, avalanche reactivity could vary widely throughout the zone. Evaluate conditions and adjust the forecast as needed for your travels. 

    You can expect to see the majority of avalanche activity near and above treeline, as warmer temperatures when much of the snow came in led to a heavy, possibly moist, snowpack below and near treeline. We're looking forward to the cooling trend starting Monday night, when lower elevations will likely get snow over previously wet surface. It's going to be chilly for the next few days! If more than 6 inches of lower-density snow falls below treeline overnight, be sure to evaluate for avalanches running on steep slopes at that elevation band as well.   At all elevations, you can expect to encounter dry loose avalanches, or sluffs, in steep, non wind-affected areas in any lower density, dry surface snow that fell overnight. They will likely remain small, but be aware of them knocking you or a partner over. 

    Evaluate steep slopes before you head out onto them by digging pits to investigate the bonding of the storm layers, and using small test slopes. If you're in a location that saw well over a foot of new snow, small test slopes are not likely to give you accurate data. If you see any new avalanches or your feet or sled initiates long, shooting cracks, stick to lower-angle terrain.  When in doubt, steer around slopes steeper than 35 degrees during your outing on Tuesday. 

    (2/20/2023Storm slab avalanches which occurred Monday in the Snoqualmie Pass zone, which generally got a bit more snow than the West North zone. Depending on where you are in the West North zone on Tuesday, you could trigger an avalanche like this.  SS-N-D2-R2-U Photo: Dallas Glass

Avalanche Discussion

Avalanche Accident Colchuck Pk, East Central Zone

We’ve received preliminary information of an avalanche incident on Colchuck Peak, SW of Leavenworth, WA. (East Central Zone) The accident occurred on Sunday, February 19 and involved a group of 6 backcountry travelers. Three members of the group are suspected to have been buried and perished in the event. Another sustained injuries and was evacuated by SAR.  Rescue efforts are ongoing. NWAC is working with Chelan County Sheriff’s office and will make updates as more information becomes available.

 Forecast Discussion:

The Baker backcountry only got 3 inches of snow Sunday night and most of the day Monday, before it finally started receiving more intense snowfall starting around 4pm. It should be a good day up there on Tuesday! The Wells weather station to the south reported over double the amount of water that the ski area got, and riders at the Baker NRA were reporting 2-3 feet of new, heavy snow and natural avalanche activity during the day. This is a surprisingly variable amount of snow for the zone, and avalanche activity will be very different depending on where you go on Tuesday. 

As the storm winds to a close, there is a very small chance that an avalanche could step down to a subtle weak layer, which may be 4-6ft below the snow's surface. This layer is near and above treeline, and was mainly identified in the Canyon Creek area. The last time an avalanche occurred on this layer was over a week ago, on Feb 11. We're keeping this concern on our radar through this storm as the final test on the layer. If an avalanche does occur, it will be very large and destructive, and could possibly travel down, below treeline. 

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