Lawinenlagebericht

West Slopes North

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Tue
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Open full map
Veraltet — dieser Lagebericht ist 2 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Look for active wind transport and fresh wind slab formation, especially around and north of Hwy 542. The risk of triggering a large slab avalanche that releases in deeper layers becomes lower each day, but the weak snowpack structure won’t be changing anytime soon. 

 

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Unlikely
    Größe
    2–2.5

    There is still a chance of triggering a large slab avalanche that releases in a layer of weak faceted snow 2-4’ below the surface. The likelihood will increase in areas where there is renewed loading in the form of wind transported snow. There might even be a natural avalanche or two if wind speeds and loading are greater than forecast. 

    No human-triggered slab avalanches were reported in the last week despite lots of traffic in a variety of avalanche terrain. On the other hand, observers in the Baker Backcountry reported a collection of large natural avalanches about 2.5 miles southwest of Artist Point in the West Fork of Swift Creek (photo). They may have released during or immediately following fresh snowfall on Feb 5th or 6th. 

    If you were to trigger one it would be in a wind scoured area with less new snow over the weak layer, on an unsupported slope like a steep convex roll or above a cliff, or in less traveled, remote terrain.  A heavy load like multiple snowmobiles, large groups of people, or big cliff drops might trigger an avalanche where the load of a single person or sled would not. 

    (2/9/2025)

    This slew of natural avalanches in the West Fork of Swift Creek were reported on Sunday. The time of occurrence and weak layer are hard to pin down. Whatever the details, it's proof the layering is still out there to produce slab avalanches. North aspect at 5500'.

    Photo: Andrew Richardson

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–1.5

    Strengthening outflow winds (i.e. northerly and easterly) should affect the northern part of the West North forecast zone. Wind speeds are generally light to moderate, but forecast as strong enough to drift the plentiful light-density snow at the surface. Many areas will not see much of a wind speed increase and therefore no new wind slab formation. Stubborn or unreactive, older wind slabs might still be found.

    Actively drifting snow will show you which slopes are building fresh slabs. Track changes in snow texture and stiffness and you gain elevation and change aspects. Use simple tests like hand shears or small-slope cuts to check the bond of wind slabs to the layer below.

    (3/12/2023)

    Drifting snow shows you were not to go.

Avalanche Discussion

Loose, unconsolidated snow can still produce small avalanches, especially once it gets going in steep terrain with long sustained fall lines. Stay alert to snow moving with you downhill if descending or side-hilling steep slopes. Afternoon sunbreaks could get snow to shed from cliffs and trees which can trigger loose snow avalanches on slopes below.

Southerly aspects hold some amount of soft crust after a few days of sun while shaded aspects hold excellent riding conditions where not tracked out. There are three or more feet of right-side-up snow over the old snow surface of crusts and/or facets buried on January 30th. While these interfaces are slowly gaining strength, the surface is undoubtedly weakening on shaded slopes given high pressure, cold temperatures, and clear skies. While never a guarantee it will happen, this is setting up to see another pattern of slab avalanches failing at buried facets or surface hoar when we see more snow.

 

Abgedeckte Regionen