Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

Very stormy weather will lead to natural avalanches of various types and sizes. Expect the most dangerous conditions during periods of heavier precipitation. Put plenty of space between you and places where avalanches can start, run, and stop.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    1.5–2.5

    Heavy precipitation rates, fluctuating temperatures, significant snowfall, and strong winds. Check, check, and double check! You don’t need a big imagination to see how this will result in natural avalanches. Sure, many of them will come from wind-loaded features. However, unless it’s scoured to the old ice, any open slope should be suspect. 

    The presence of an ice crust above 5000ft and weak surfaces below could cause many of these slides to fail at the base of the new snow. In the morning, that might only be a foot or so deep, but later in the day, these slides will be much deeper and scarier. 

    Dial it way back, and stay out of avalanche terrain, particularly at middle and upper elevations.

    (1/14/2024)

    Example: Even small slopes could produce avalanches on Wednesday. 

    Photo: Joe Dellaporta

  • Loose Wet

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

    At lower elevations, we could see a variety of precipitation types: snow, freezing rain, sleet, and…yes, rain. With so much cold dry snow on the ground, you’re likely to see rollerballs and natural wet loose avalanches. The keys will be the rain-snow line. If you feel warm and wet, so does the snowpack. 

    Most of these should stay fairly small, but on longer slopes, they could entrain plenty of snow and grow larger. Give steep slopes a wide berth if you’re near or below the rain-snow line.

    (1/4/2024)

    Example: Rain could trigger wet avalanches at lower elevations. 

    Photo: Dallas Glass

Avalanche Discussion

Buckle up! We’re at the start of another prolonged snowy period that seems to favor the Mt Hood area. If you’re out on Wednesday morning, conditions might not seem all that dangerous. However, as the storm intensifies, expect conditions to change quickly. What appeared pretty manageable could suddenly feel very scary. 

Going into this stormy period, there are a couple of layers to keep in mind. 

-1/16 Interface: This new interface is an interesting one. A very slick ice crust formed on much of Mt Hood this past week above 5000ft and extends to at least 8500ft (the top of our forecast area). That could make it very difficult for the new snow to stick. Lower in the terrain, soft unconsolidated snow lingered. Down there, you might find weak facets or surface hoar at this interface, allowing avalanches to trigger very easily and even remotely. 

-Early January Facet/Crust Layer: This potential weak layer is deep (6-8ft)! While we haven’t seen avalanches on it recently, deeper persistent slabs have occurred north (West South Zone) and south (Central Oregon Avalanche Center). Will this new load wake it up? Hard to say. These much bigger and deeper slides would be most likely on NW-N-E aspects above 5500ft, where significant snow existed prior to the New Year.

Regioni coperte