Bollettino valanghe

Central Cascades

Central Oregon Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Sat
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Open full map
Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering avalanches will be likely anywhere wind drifted snow has accumulated and primarily on north, east and south facing slopes near and above treeline. Loose snow avalanches will be possible anywhere the snow is not heavily affected by the wind. Look for signs of unstable snow such as cracking and previous avalanches and be cautious in your terrain choices; you can always choose terrain less than 30 degrees steep to minimize your exposure to avalanches.

Problemi valanghivi

  • Loose Dry

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    With cold overnight temperatures, the snow will be lacking cohesion near the surface. Dry loose avalanches in steep terrain will have the chance to entrain more snow and run farther that usual.  Be especially cautious in steep and committing terrain, above terrain traps, constrictions, and places where the terrain can act like a funnel. 

    At lower elevations where the high temperature could reach into the upper 20's F, the storm snow will likely have more cohesion by midday, and storm slabs avalanches will be more of an issue than dry loose. 

  • Cornices

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

    I observed growing cornices on Thursday and they will probably continue to grow throughout the night and into Friday. Fresh cornices can be fragile,  break easily, and can trigger slides on the slope below. Be cautious when approaching ridge tops where cornices may be lurking over lee slopes. Stepping out onto a cornice could result in a break and a fall onto the slope below. 

    (3/23/2023)

    Blowing snow and growing cornices on Thursday. East facing slope near treeline. 

    Photo: Aaron Hartz

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2.5

    On Thursday with only 4" of new snow, I found small shallow wind slabs to be easy to trigger. With the bulk of the storm snow coming in overnight and Friday, wind slabs will be building. There will be a lot of blowing snow over the next 24 hours. Some avalanches may be small, but with the current conditions wind slabs have the potential to be larger than what we normally see. Wind slabs are most reactive to triggering when they are fresh, and I expect we will see wind slab avalanche activity on Friday.

    Wind slabs may show up in places like clearings and areas with sparse trees even below treeline. Remember burned areas and slopes with dead trees can experience a big wind affect and get a lot of wind deposited snow. 

    Wind slabs will not be everywhere, so use visual clues to identify where wind slabs have formed and are building below ridge tops, peaks, and around features that catch blowing snow from cross slope winds. Monitor the depth of wind deposited snow. As the new snow stacks up and wind slabs become deeper, resulting avalanches can become larger. 

    Utilize small features or low angle terrain to evaluate the wind slab problem. Look for cracking in the surface snow. Anytime you observe cracking in wind drifted snow, or if you see signs of previous avalanches, these are good indicators that you can trigger an avalanche. 

    (3/23/2023)

    On Thursday, wind slabs were small and shallow on east facing slopes near treeline, but easily triggerable. It was easy to get cracking like this in the wind deposited snow. Wind slabs will be larger on Friday.

    Photo: Aaron Hartz

Avalanche Discussion

The current storm started off on the slow side but is now ramping up. The bulk of the incoming snow will fall Thursday night through Saturday morning. Lots of snow with cold temps will bring great powder riding, but also remember its during the bigger storms when our avalanche problems are most present. Stay sharp, look for signs of unstable snow, evaluate the snow, and remember you can always back off on your terrain choices anytime you are unsure about the snow stability. 

Regioni coperte