Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

Recent rainfall has created dangerous avalanche conditions at all elevations around Mt. Hood. Wet avalanches of all types and sagging cornices remain a concerning problem around steep terrain. Avoid travel on and limit your time spent under steep slopes, which also include upper canyon run-outs that very large avalanches can snake through during and after rain events. 

Problemi valanghivi

  • Wet Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3.5

    Destructive wet avalanches remain a concerning problem on Monday. Sunday introduced 1 inch of rain on a dry snowpack, and it is forecast to continue during the overnight hours. While Monday should be a bit drier, you should still shape your travel decisions with the consequences of large, unpredictable avalanches in mind. Wet loose avalanches are often considered to be more manageable, but don't be surprised if these are easy to trigger and grow large quickly. They could be triggers to larger wet slab avalanches. 

    Leading up to this rain event, we saw over 70 inches of new snow and importantly, a pattern of widely propagating, large ( to very large) avalanches around Mt Hood. We’re unsure what these large avalanches failed on, but these weak layers could be layers that wet slab avalanches fail on. It's unique for us to head into a rain event with so much new snow and documented slab avalanche activity, so ease out of this warm-up with caution until the meltwater production shuts off with a proper refreeze. 

    Wet avalanches are notoriously hard to predict and forecast, so the best strategy to increase your safety buffer is to simply avoid travel on and below steep terrain. This also includes upper canyon run-outs that D4 avalanches gouge through every year. 

    Sagging cornices and glide cracks may exist across the zone. Give these chunks of snow and frowning cracks a wide buffer. 

    (3/22/2025)

    One of the many widely propagating avalanches that were reported on Saturday. 

    This natural avalanche occurred on a SE aspect @ 7200 ft. It likely ran on 3/21. 

    HS-N-R3-D2.5-U

    Photo: Joe Dellaporta

Avalanche Discussion

Forecasting wet avalanches is tricky, especially each day we move past the initial rain event without a proper refreeze. We suspect the peak activity occurred on Sunday as rain fell on a dry snowpack, but historically we have seen very large wet avalanches fail several days after the initial rain event or warm-up. These past avalanche cycles are a healthy reminder that water will continue to move through the snowpack during these warm periods despite the decrease in rainfall amounts. It keeps us on our toes as forecasters, and it should help keep your terrain selection simple until we see a proper refreeze later this week. 

Prior to the rain event, weather stations exceeded 70 inches of new snow ( > 7 in SWE) at the weather stations across the zone. As you’d expect, the reported avalanches grew larger as the week progressed. As of Saturday morning, avalanche professionals across the zone reported numerous natural, D2-D3 avalanches that likely failed during the minor warm-up on March 21st. We’re unsure what these avalanches failed on, but some propagated far and ran a good distance. Additionally, the Mt Hood Meadows Pro Patrol reported triggering several large avalanches at all elevations during avalanche reduction work. The largest avalanches, with crown depths ranging from 3-5 ft, occurred in wind-loaded alpine terrain.

You can add to the forecast! Submit an observation here. 

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