Avalanche forecast

Mt Hood

Northwest Avalanche Center
View on map

Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
Open full map
Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You can trigger small, fresh wind slabs formed from winds and light snowfall early Saturday. Look for signs of active or recent wind transport, such as blowing snow or freshly scoured ridges to identify and avoid wind-loaded slopes at upper elevations. At lower elevations, early season obstacles should be your primary concern.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Shallow slabs will build anew at higher elevations with several inches of snow combined with moderate winds. This means that you are most likely to trigger a slab where you find signs of active wind transport (blowing snow) or wind-affected, chalky or stiff snow on heavily wind-loaded slopes (new snow 6 in or greater).  When in doubt, choose wind-scoured or lower-angle terrain and navigate away from features such as cornices and convex rolls. Older large wind slabs are likely to be stubborn and trending to unreactive due to recent warming, but pay attention for punchy layers in the storm snow earlier in this weak and if you encounter it, dial back your ambitions. These slabs were the culprit for a snowcat-triggered avalanche early Thursday at a local ski area. Rain expected to fall early Saturday is likely to heal wind slab problems near and below treeline.

    (11/27/2020) Active wind loading/blowing snow, rime on trees and cliffs, and snow drifts at Mt. Rainier

Avalanche Discussion

Under the influence of a ridge of high pressure with ample sunshine, temperatures rose into the 40's on Friday at NWAC stations below 7000 ft. 

On Saturday, snow levels should start around 7000-8000 ft as light rain and snow arrives, with a rapidly descending snow line as the morning progresses. Most of the snowfall should end during the morning with some light snow flurries lingering in the afternoon. This new snow combined with moderate winds may or may not be sufficient to create much of a new wind slab problem.

With 44-50" of settled snow at mid elevation, the Mt Hood snowpack is far above average for this time of year.  After our initial snowfall, a rain event and warm period built a supportable rain crust on November 16th. This has served to lock in the base of the snowpack and batter down vegetation creating surprisingly good travel conditions and snow coverage for November.  Snow that fell last week is generally well bonded to the 11/16 rain crust and no significant avalanche activity was observed in the recent snow.  Friday and Saturday (11/20-21) brought sunny, calm, and warm conditions. The snow surface stabilized as a crust formed on solar aspects and lower elevations. Higher elevation and shaded slopes largely escaped the melt cycle and good travel conditions were found on these slopes throughout the weekend. Tuesday and Wednsday brought 6-14" of snow which produced some (now old) wind slabs sitting on top of these crusts and higher elevation old snow surfaces. 

Early season conditions exist, particularly in the trees. Travel will be more hazardous and terrain features look different than you expect. Avalanches, including small ones, will be more dangerous, potentially raking you through shallowly buried obstacles. Rivers and creeks are likely still open. 

Now is a great time to run through your safety equipment and make sure everything is in good working order. CLICK HERE for more information on early-season equipment checks. What did you see out in the field? SHARE YOUR OBSERVATIONS with NWAC and the backcountry community. Check out this BLOG POST and VIDEO TUTORIAL to find out more about why observations are so important and how you can view and share information on NWAC’s new public observations platform.

The Covid19 pandemic continues to be a major health and safety concern. Avoid unnecessary risks that could result in a rescue or stress medical resources. Follow local and state guidelines and wear a mask when appropriate. Maintain social distance and recreate responsibly and closer to home. 

Regions covered