Avalanche forecast

Mt Hood

Northwest Avalanche Center
View on map

Avalanche danger

Thu
Alpine
4 · High
Treeline
3 · Considerable
Below
3 · Considerable
Open full map
Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

A dangerous snowpack with multiple reactive storm interfaces will be stressed to the breaking point by significant snow and wind-loading Tuesday night and Wednesday. At upper elevations natural avalanches are likely, human-triggered avalanches are very likely and these could be very large, potentially running thousands of feet. Near treeline, you may be able to travel safely if you stick to terrain less than 35 degrees exclusively and avoid large avalanche path runouts.

Avalanche problems

  • Wind Slabs

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

    All the ingredients are in place for an avalanche cycle on Mt. Hood, Wednesday: Snowfall piling up overnight and during the daylight hours,  strong winds overnight that stress lee slopes further, and reactive interfaces that will fail under loading. Very large avalanches have been occurring sporadically on Mt. Hood for over a week since the avalanche cycle started. While some (such as the one in the photo) occurred above NWAC's forecasting terrain, the ingredients for natural or human-triggered avalanches are in place at lower elevations near and especially above the treeline. Keep it simple and avoid all avalanche terrain including large avalanche runouts. 

    (1/5/2021) This very large natural avalanche on the north side of the mountain at 10,200 ft occurred over the weekend. Don't linger in runout zones where very large avalanches may run several thousand feet to lower elevations.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    We're nearing the end of a major storm cycle and dry snow is unconsolidated, very deep, and the upper snowpack is complex with multiple reactive interfaces. We're adding a new interface going into Wednesday. Reactive and easily propagating storm interfaces found Tuesday down 4" and 18" have us concerned going into Wednesday. Unfortunately, we don't need much additional snow to create dangerous storm slabs. Yet, we expect 1 ft of additional snow at elevations above 5500 ft Tuesday night and Wednesday with slightly less below treeline where precipitation may start as rain, creating a natural avalanche cycle Tuesday night. Avalanche activity, whumphing, cracking, or reactive test slopes all confirm the strong importance of keeping your slope angle less than 35 degrees if you choose to travel on open slopes near or below treeline. Conditions are generally safer in mature forests.

    If a rain crust forms at lower elevations, this might help to mitigate the danger below treeline, so watch for fresh snow building above the crust and if you get 8" or more, expect reactive storm slabs.

    (1/5/2021) Reactive snow in a test pit, N aspect, 6300 ft.

Avalanche Discussion

The brief relative break in the weather on Tuesday will be a thing of the past on Wednesday. However, if the storm underproduces in terms of winds and temperatures, we think our travel advice hold and conditions will be dangerous. 

Fresh cornices are sensitive so give them a wide margin for safety both from above and on the slopes below.

If you plan to travel in the backcountry Tuesday, make a plan that will keep you out of the path of a very large avalanche from higher on the mountain and avoid all slopes above treeline or avalanche paths and runouts descending from these elevations.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regions covered