Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Increasing wind speeds may start drifting available soft snow into shallow drifts in the alpine. Once you lose the wind, you lose the problem. So consider sticking to more sheltered slopes out of the wind zone if you observe blowing snow or notice fresh drifts.

Problemi valanghivi

  • Wind Slabs

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

    Most slopes in the alpine are wind-pressed rather than wind-loaded at this point. However, light snowfall accompanied by strong NW winds, should start blowing any new and available snow into shallow drifts above treeline. Look for these shallow slabs of wind-drifted snow to develop along the leeward side of ridges, over convex rolls, and under cornices. You should be able to easily spot these fresh drifts. Just use visual clues such as blowing snow and pay attention to what direction winds are depositing new snow. Avoid these fresh pockets if you notice signs of instability such as shooting cracks. 

    Use visual clues such as blowing snow to help you identify slopes of concern. 

    Photo: Joe Dellaporta

Avalanche Discussion

Sunday will be a transition day for Mt Hood. Look for light snow to develop with moderate/strong ridgeline winds. We’ll be joining the party on Monday, with the biggest punch of precipitation moving in Monday evening. This will certainly bring a sharp uptick in avalanche danger. 

The past few days have offered good skiing on more shaded aspects with a fairly strong upper snowpack. The old wind slabs that developed from our last storm on 2/13 are now unreactive and welded into place. 

Over the past couple of days, I have been out in the Tilly Jane and Pea Gravel Ridge zones.  My goal was to track surfaces before heading into a stormier regime. In the Tilly Jane area I did observe weak surface snow (near-surface facets/ surface hoar) in most below treeline and near-treeline areas. Surface hoar was found in specific areas with minimal canopy at middle elevations.  In the Pea Gravel Ridge area I found the opposite, with moist snow at the surface on most aspects besides north. 

The big question mark will be if this weak snow survives the wind speeds and the warm temperatures from the last day. So keep an eye as you travel since this could be our next weak layer in a day or two. 

Let us know what you see by submitting a public observation. 

 

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