Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Winds and additional low-density snowfall sustain the danger. You can trigger an avalanche within wind-affected or drifted snow at any elevation, particularly on the lee sides of ridgelines. An isolated very large natural avalanches from the upper mountain remains a possibility, so limit your exposure to connected terrain including long canyon runouts.

Avalanche problems

  • Wind Slabs

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

    There's a lot to think about within this single avalanche problem on Monday, so the best advice is to stick to simple, low-consequence terrain less than 35 degrees away from potentially dangerous avalanche paths and runouts.

    The cold, snowy pattern continues on Monday with moderate winds at least into the morning hours, maintaining reactive wind slabs at all elevations. The 6+ ft of snow that has fallen in this storm cycle is right-side-up in wind-sheltered terrain, so your risk of triggering an avalanche should focus on wind-affected snow and wind-loaded terrain.  These areas are isolated and more proximal to ridgelines below 5500 ft, but rapidly become widespread and potentially large to very large as you ascend upward. Put another way, increasing potential avalanche size with elevation dramatically decreases your likelihood of surviving an avalanche while your probability of an involvement ratchets up as well. A rider-triggered pocket on Gunsight Ridge highlights the risk of subtle convexities within wind-rippled snow 5600 ft. As you notice increasing signs of wind-affected snow, steer to the wind-stripped sides of ridges or seek supported slopes less than 35 degrees. Red flags like shooting cracks in wind-drifted snow are signs you'll likely trigger an avalanche on nearby steep slopes.  Make sure you're not traveling in terrain connected to upper-elevation start zones. Although the threat may be decreasing given five days since the last reported D4 avalanche, an isolated D4 natural avalanche from the upper mountain isn't out of the question. Such an avalanche runout extends miles down relatively flat canyon bottoms. If you must cross a drainage, do so quickly and as far down the canyon as possible.

    Cornices are growing large and sensitive. They may break farther back than you expect, and fresh cornices can help you highlight the wind-loaded slopes below that you want to avoid.

    (3/3/2024)

    Small rider-triggered slab within wind-affected snow below treeline. 5600 ft, SE aspect on Gunsight Ridge.

    Photo: Trevor wright

Avalanche Discussion

Storm cycle totals might be in the 7 ft range by the time the storm cycle winds down Monday night. At lower elevations, this snow fell on very shallow to non-existent snowpacks. Small saplings can easily hold up this snow, creating massive voids. If you fall into one, it can be difficult to extract yourself, and it is almost impossible if you're suspended upside down by your mode of transport.  Deep snow immersion/tree wells (SIS) remains a significant concern in sheltered terrain on Monday  Ride with a partner and keep one another within sight. A SIS resulted in a fatality on Friday in the Cascades serves as a strong reminder of the risk.

Mt Hood got a relative break in the snowfall Saturday night into Sunday morning, but not the winds. Snowfall picked up Sunday afternoon with around 4" of snow by 5 PM. Observations have been limited to below 6500 ft by ongoing cloud cover. At middle elevations, Mt Hood Meadows Patrol reported sensitive 3-5" slabs on previously mitigated and skier compacted terrain. Slab size and reactivity may be significantly more elevated in backcountry terrain. 

An observation from lower-elevation backcountry terrain near Mt Hood Meadows suggests that several interfaces may exist within the storm cycle snow. While we think these instabilities will continue to settle with time, we have limited information on them at the moment. Consider them before engaging with large steep or unsupported slopes, even in less wind-affected terrain. There's a lot of snow that could move downslope. It could fail as a storm slab on any subtle interface buried 3/3, on one of the aforementioned interfaces, or as a dry loose avalanche moving down the hill with you on a steep slope. The massive volume of snow means there's plenty of snow to move downhill on a steep or very steep slope. Additionally, if the sun happens to make an extended appearance, expect loose avalanche activity that could imperil you from the slopes above. If this occurs, seek cooler shaded aspects and move away from steep sun-exposed slopes.

2 very large avalanches occurred in Heather Canyon, depositing debris several thousand feet down into Clark Canyon up to 50'(!) deep in places.  These avalanches likely released Tuesday night and again on Thursday morning.  It's unknown whether or not one or both slides occurred during avalanche mitigation due to storm conditions and poor visibility. It's a stark reminder of the massive avalanches that can happen on Mt Hood during or following a multi-day storm cycle and often during periods of poor visibility. 

All of the storm snow rests on the 2/24 interface.  Going deeper in the snowpack, a series of crusts and pockets of weak snow existed above the stout Early February Crust (EFC).  Prior to this storm cycle, these layers produced inconsistent snowpack test results and showed signs of gaining strength.  These layers are now buried several feet deep.  

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