Avalanche forecast

West Slopes Central

Northwest Avalanche Center
View on map

Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You can trigger a slab avalanche in wind-drifted snow at upper elevations. Bypass steep terrain where you suspect a stiffer slab sitting on weaker snow below. Wet avalanche activity should diminish Monday if clouds limit warming from the sun. 

715 am Update: Near Treeline raised to Moderate, reflecting an increased chance of shallow new wind slabs. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Stubborn wind slabs from the last storm and shallow pockets of newly wind drifted snow should both be on your radar tomorrow. Alpine winds are forecast to be just strong enough to transport recent new snow into small but fresh slabs.

    If you trigger a slab avalanche Monday it would likely be on downwind slopes with terrain features like convex rollovers, gully walls, or around cliffs and rock outcroppings. Look for blowing snow, changes in snow consistency, or visual clues like cornices and wind-scoured ridgelines to identify areas of wind slab. 

    As usual, shift to a more conservative plan if there is stronger wind and more active loading than expected.

    Small wind loaded features at ridgeline can serve as test slopes to gauge the reactivity of fresh wind slabs.

     

Avalanche Discussion

Blue sky and full sun spurred a round of wet avalanches to D2 from Snoqualmie Pass to Mt Baker Sunday. Mid-level clouds are forecast to limit warming - and therefore avalanche activity - on solar aspects Monday. Be on the lookout for more avalanche activity if the clouds fail to keep the sun in check. Wet loose avalanches are unlikely and travel conditions are poor where a stout crust caps the snowpack.

No new avalanches in storm or wind slab layers were reported in West North and Stevens Pass. Avalanche activity on shaded slopes was limited to small sluffs in steep terrain. Minor wind transport was noted on some ridgelines in both zones but it was not enough to build new slabs. A fresh crop of surface hoar appeared in many areas and probably survived the day on shaded slopes.

An active weather pattern December 28-31, 2022,  brought significant new snow to the west slopes of the Cascades.  At White Chuck, this has settled to 18” over the crust from the rain event the prior week with 15-20” now over the same rain crust in areas surrounding West Central.   

Human and natural avalanche activity peaked on Saturday morning. Large human triggered avalanches were reported from mid-elevation terrain around Hwy 542 with smaller storm and wind slab avalanches in Stevens and Snoqualmie Pass. Very large natural avalanches were observed in alpine terrain with improved visibility Sunday. 

Regions covered