Bollettino valanghe

Mt Hood

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
Open full map
Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Use caution on wind-loaded slopes above treeline where we have limited information following unsettled weather and poor visibility.  Large avalanches are possible in isolated areas. Below treeline, watch for small loose wet avalanches on very steep southerly aspects if the sun comes out for an extended period.  

Problemi valanghivi

  • Wind Slabs

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

    You may experience a mix of older and newer wind slab concerns near and above treeline Thursday.  For older wind slabs, probe for areas of wind-stiffened snow. Milder temperatures and time should have helped wind slabs formed late Tuesday and Wednesday stabilize. We still have a lot of uncertainty about avalanche conditions above treeline and into the true alpine above NWAC's forecasted elevation bands.  Keep that in mind if you start to venture above treeline.

    Cornices have grown large over the recent storm cycle. Besides steering around cornices, give them plenty of space while traveling along ridgelines. Also, use them to help you determine which slopes have been wind-loaded most recently.   

    SE winds will increase Thursday afternoon and begin to re-distribute snow above treeline.  Depending on the amount of available snow for transport, this may create shallow and fresh wind slabs on a variety of aspects before the end of the day. 

    (1/4/2021) Fresh cornices formed near treeline on Monday.

  • Loose Wet

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

    If the sun comes out before winds increase in the afternoon, small loose wet avalanches are possible below treeline on steep southerly aspects.  Watch for signs of increasing instability like roller balls and pinwheels as natural indicators that it's time to switch aspects or move to lower angle terrain. Small loose wet avalanches can be more powerful than you think.  Consider the consequences of even a small avalanche near terrain traps like cliff bands, trees, and exposed obstacles.  

    Ex: Rollerballs and small loose wet avalanches were triggered by travellers during a period of mild and sunny weather on a nearby volcano, Mt St Helens.

Avalanche Discussion

A series of thin rain crusts can be found in the snowpack up to 6000' interspersed with recent moist snow.  With 4-6 inches of new snow and generally light winds expected Wednesday night,  avalanche concerns should be limited to new snow problems in the below treeline band.  Near and especially above treeline we have less certainty exiting a period of unsettled weather and poor visibility.  Snowpack tests on N aspects around 6300' on Monday indicated propagation was likely on a layer roughly 1.5 below the snow surface. This layer will be deeper in wind loaded areas.  We don't know of any new or recent avalanches down to these depths, but consider your terrain choices before jumping onto large open slopes above treeline Thursday. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte