Bollettino valanghe

Central Cascades

Central Oregon Avalanche Center
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Pericolo valanghe

Thu
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering a Wind Slab avalanche near treeline and and at alpine elevations will be likely on North and East slopes.  So far these avalanches have been quite small with minimal amounts of new snow.  On Wednesday the forecast is for 5-8 inches of new snow which may create avalanches large enough to bury or injure a rider.  If we only receive a couple of inches of snow (as we have so far) than Wind Slab avalanches will remain mostly small.  The Considerable hazard rating reflects the higher snowfall forecast.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Recent snow showers have consistently delivered significantly less snow than  weather forecasts have anticipated.  This means that the Moderate Southwest winds have had less snow to move around and any Wind Slab avalanches have been relatively small (D1).  If new snow forecasts of 5-8 inches overnight and on Wednesday verify than these Wind Slabs could be large enough to bury or injure a rider (D2).

    Actively blowing snow and recent cornice growth are great clues as to where Wind Slabs are likely to be.  Remember that wind blown snow can be 3-5 times as deep as the new snow in sheltered glades and meadows.  Paying attention to the depth of new snow in both these sheltered areas as well as on lee slopes where snow has blown in, can give you a clue as to how large a potential Wind Slab avalanche might be.  Signs of potential Wind Slabs include: cracking in the surface snow on lee slopes and easy hand shear results on these slopes.

    If you have doubts in snow stability find less steep slopes or avoid North and East slopes below ridgelines.

Avalanche Discussion

Despite continuous snow showers since Sunday morning, riding today was still a bit "scratchy".  At noon on Tuesday there was approximately 15 cm. of cold light snow overlaying a supportable melt-freeze crust.  These same "dust on crust" conditions (small amounts of snow and cold temperatures) accompanied by Moderate and Strong winds have created shallow Wind Slabs on North and East slopes.  If we receive significant new snow on Wednesday, we can expect an increase in the size and thus danger of these avalanches.

Regioni coperte