Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
4 · High
Treeline
4 · High
Below
4 · High
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Highlights

Heavy rain and warm temperatures will create very dangerous avalanche conditions at all elevations Saturday night and Sunday. Wet avalanches will fail without warning and could run long distances. Avoid all areas where avalanches can start, stop, or run, including open areas and canyon bottoms connected to higher elevation start zones.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2.5–3.5

    Sunday is a great day to keep it simple and avoid all avalanche terrain.  We're expecting over 4" of liquid water to enter the snowpack at all elevations (up to at least 8000 ft). Wet slabs are highly unpredictable, failing as water runs through the snowpack and pools on crusts or weaknesses...and we know the Mt Hood snowpack has plenty of crusts. A very large wet slab would likely be unsurvivable. These may initiate in middle or upper elevation start zones and could run to valley flats and down canyon drainages. Crossing open slopes, even flat terrain connected to upper elevation start zones isn't worth the risk. Don't tempt fate and instead choose mellow terrain or indoor activities while the snowpack adjusts to rapid change.

    Also expect gouging, dangerous wet loose avalanches initiating naturally on steep open slopes, and snow shedding off rocks and cliffs. During this warm, rainy period, we expect a high risk of cornice fall as well.

    Example: A very large D3 avalanche in Heather Canyon. running down to and along the canyon bottom.

    Photo: Joe Dellaporta

Avalanche Discussion

The snowpack will look very different by Sunday as rainwater consolidates and moves through a mostly cold snowpack, with plenty of crusts interspersed even on shaded aspects. An atmospheric river will pummel the region Saturday night through Sunday evening, creating very dangerous conditions throughout the time period. 

Moderate ridgeline winds ramped up on Friday and have stayed elevated ever since. A pulse of moisture brought 0.3" of water equivalent Friday night, which likely translated into wet snow at upper elevations. The main event started Saturday afternoon with rapidly rising snow levels and 0.4" SWE by 5 PM.

The last significant snow event brought 6-10" of snow accompanied by strong W and WNW winds and winds. This event brought some impressive wind slab activity. A very large natural avalanche failed on an E aspect in White River Drainage.  Multiple size 2-2.5 (large) avalanches were triggered by MHM patrol on E and SE aspects, including this one. This activity likely involved the 2/13 interface, which may wake back up Saturday night into Sunday with the heavy rainfall.

In the gallery, we're including a variety of the types of wet avalanche activity we're expecting to see over the next 24 hours. A crown profile from a recent large wind slab also shows the potential for structural weaknesses in the snowpack that can be exploited by rainwater moving through the snowpack and triggering wet slabs.

You can contribute to the avalanche forecast! Let us know what you see by submitting a public observation here. 

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