Avalanche forecast

Central Cascades

Central Oregon Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

We've received over a foot of new snow since Saturday accompanied my Moderate and at times Strong winds.  Wind Slab avalanches could be large on north and east facing slopes where the wind has blown that new snow and packed it into cohesive slabs.  While these Wind Slab avalanches are mostly likely at higher elevations where the wind blows freely, strong winds can also blow snow further down slope than we are used to.  Cornices have also been growing rapidly.  Give them some extra room as a collapsing cornice can be both an avalanche in itself, and can trigger a Wind Slab avalanche on the slope below.

Avalanche problems

  • Wind Slabs

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

    Several D1 Wind Slab avalanches were reported on Tuesday.  During much of this storm I have been finding very deep pockets of wind loaded snow on north and east slopes, but these wind slabs have been stubborn or unreactive.  This hasn't made me feel great though; when it comes to avalanches large and stubborn doesn't instill a warm fuzzy feeling.  On Tuesday I observed strong west winds and intense blowing snow on Tumalo, which means wind slabs are still building.  If high pressure lures you into higher elevation terrain, careful snowpack analysis will be important before traveling on large or steep lee slopes.

    Remember that Wind Slabs can occurr on any slopes that the wind has blown snow onto.  Strong winds like I saw today often load snow further down slope than we are used to.

    I've extended the Wind Slab avalanche problem onto south slopes due to shifting winds on Wednseday.  I'm not sure if the wind will be strong enough by then to move snow; likely in the alpine, maybe not near treeline.

  • Cornices

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

    Cornices have been growing rapidly with the new snow and Strong winds.  Of course cornices are always a bit unpredictable as they can break farther back than a rider might expect.  We tend to add Cornice Fall to our avalanche problem list when we see them growing rapidly (as I have in the last few days), or when they may be weakened by warm temperatures or rain (not the case this time).  I've been giving cornices a little bigger margin of safety in the last few days, whether that's when they are above me, or when approaching from the backside.

Avalanche Discussion

Since Saturday we have received 30-40 cm. of new snow.  The only avalanches that we've observed or have been reported have likely been Wind Slabs, although some have existed a bit lower in the terrain than we might expect.  Beneath the latest storm snow lies a sun crust from the warm sunny weather we had late last week.  This crust exists on all aspects except for north.  So far I haven't seen any indication of persistent weak layers forming near this crust.

Regions covered