Avalanche forecast

Mt Hood

Northwest Avalanche Center
View on map

Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Saturated snow and water pooling on crusts maintain the risk of destructive wet slab avalanches days after peak activity. Continue to minimize risk by reducing exposure to steep, open slopes. If you encounter firm crusts up high, make sure you can arrest a fall.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    We're in the wet slab gray area of lowering probability, but high consequences. We're several days past the peak of a wet slab cycle, but we're not out of the woods yet. We might start getting the much-needed refreeze at the highest elevations, but temperatures remain uncomfortably mild at most NWAC forecast elevations. Two factors keep us on edge: (1) additional snowmelt with temperatures in the 30s and low 40s, along with patchy sunshine; and (2) recent rainwater working deeper into the snowpack. As water continues to seep deeper into the snowpack, it could pool on previous dry crust interfaces. This provides the lubrication necessary for a heavy, dense slab to release without warning. Wet slabs have a way of surprising novices and seasoned professionals alike. They can be triggered by a rider, cornice fall (we've seen multiple examples in the past 3 days), or the lubrication of a weaker interface above a crust. The long tail of potential slab release makes this problem really difficult to forecast.

    To stay safe, continue to reduce your exposure to open slopes 35 degrees and steeper. Since a rogue natural avalanche remains possible, keep your eye to ensure there are no steep slopes above you. Recent wet avalanches serve as a reminder that a very large wet slab can run long distances on low angle or even flat terrain. 

    With water saturing the snowpack: Glide cracks can release off smooth bedrock slopes and may be large. You can also trigger smaller wet loose avalanches within the saturated snow near the surface on slopes steeper than 35 degrees. 

    (1/29/2024)

    A natural wet slab in upper White River Canyon.

    WS-N-R1-D1.5-U

    Photo: Joseph Dellaporta

Avalanche Discussion

Temperatures at 5500 and 6500 ft on Mt Hood rose above Freezing last Friday and haven't looked back. The warmest temperatures occurred Monday afternoon with temperatures at these elevations around 50F with mostly sunny skies. We're expecting a gradual cooling trend with more cloud cover and continued winds on Mt Hood for Tuesday.

NWAC forecaster Joe Dellaporta made use of the fine weather to explore a variety of aspects and elevations on the south side of Mt Hood near Timberline. He found evidence of small, large, and even approaching very large recent wet loose and wet slabs that were a day or two old.  Some originated from the upper mountain. Additional similar avalanches were reported by Mt Hood Meadows Patrol on Sunday: 2-3 large D1.5-D2 natural avalanches. The activity near Mt Hood Meadows focused on NE aspects in the 6000-7000 ft range. Photo evidence in the gallery. By Monday afternoon, Joe found firmer crusts forming above 7000 ft on west aspects, with improved riding conditions on S aspects as a more breakable crust formed. He reported rain runnels up to at least 9000 ft. A snow profile (pictured), illustrates water saturation reaching around 16" into the snowpack at 8400 ft. Middle elevations had around 18" of boot penetration, but snow surfaces were becoming less prone to wet loose activity.

These middle elevations might remain the most hazardous on Tuesday as temperatures cool and crusts form at upper elevations. Thick, supportable crust formation could reduce your risk of wet avalanches, but a slide-for-life hazard may develop. Make sure you have appropriate sharps to arrest a fall on a steep slope if you encounter these conditions. Riding conditions may start to improve in some areas with a freeze-thaw cycle, but consider the underlying water seeping through the snowpack before taking undo risk on steep terrain.

A very large (D3-4) avalanche reported by seismograph on Friday evening on the Reid Glacier Cirque had a starting zone of around 8000 ft and ran for around 4 minutes. An avalanche of this size would be unsurvivable. While the likelihood of such an avalanche gradually decreases on Sunday, the possibility should make you question your need to travel in terrain connected to very large start zones originating from the upper mountain, particularly during the morning hours. 

Regions covered