Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
1 · Debole
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

Despite mild temperatures, overcast skies will once again dampen the potential for wet snow avalanches.  Stay out of and away from extreme terrain features, anywhere you find wet and mushy snow.  You're likely encounter variable surfaces on the upper mountain, alternating between chalky wind-textured snow and firm icy surfaces. 

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1–1.5

    Sunday may feel a lot like Saturday when it comes to cloud cover.  That will likely limit how much the snow surface softens despite warm temperatures and high freezing levels.  Southerly or sunny slopes are unlikely to soften much at upper elevations in any event, given how wind-packed or stripped the snow surface has become.  

    You still need to be aware of wet, punchy snow.   Avoid travel above or below terrain traps where a small wet loose avalanche could do damage.  Continue to give cornices a large berth when travelling along ridgelines during this warm stretch.  

    Small wet loose avalanches and rollerballs in very steep terrain of the Polallie Headwall that likely released midweek. 

    This is the sort of terrain you could get into trouble with quickly even with a small avalanche. 

    Photo: Ryan Matz

Avalanche Discussion

Heading into the weekend, wind and sun had blasted the mountain.  NPS Climbing Rangers found that the widespread rain crust formed on Tuesday had eroded from the persistent westerly winds above 7000' while traveling on the NE side of the mountain.  The upper mountain was highly variable, a mix of chalky, wind-textured snow and firm, icy-scoured surfaces.  

 Mt Hood Meadows Pro Patrol tested wind-loaded terrain in their upper bowls on Thursday with explosives and did not produce any new avalanches of note.  On sunny aspects, the same rain crust softened and in some cases broke down at middle and lower elevations, leading to rollerballs and small wet loose avalanches over the last few days (along with a window of corn skiing).   High clouds on Saturday limited how much surface crusts softened, if at all. 

After a stormy start to the week, visibility cleared on Wednesday, showing several small to large natural slab avalanches at upper elevations (D2.5 in the gallery below) that likely ran during peak storm intensity.  

If you're traveling to the north or east side of the mountain, continue to travel more cautiously, where less is known about the weaker/shallower snowpack.  A well-documented weak layer/crust interface has become a persistent slab avalanche problem just to our north, with scary avalanches triggered in the West South zone recently. Last Sunday, forecaster Joe Dellaporta found that this weak layer exists in northeastern locations of Mt Hood, including near Tilly Jane and Cloud Cap (observation here). This weak layer showed the ability to propagate during snowpack tests.  NPS Climbing Rangers found this weak layer interface in a nearby area on Friday, with indicators that the snowpack may be healing over time (see gallery below).  While this layer was easy to identify here, it wasn't as obvious on the south side of the mountain, where the snowpack was generally deeper and stronger over this crust. 

The mountain is looking much more winter-like after the last few storms.  That said, continue to use caution at lower elevations and on thin-coverage aspects.  Allow extra time for stream crossings,  open holes in the snow,  etc in areas with a thin snowpack. 

 Let us know what you see by submitting an observation here or on the AvyApp

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