Bollettino valanghe

Mt Hood

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

Dangerous avalanche conditions will develop on Thursday as snow and strong to extreme winds buffet the mountain.  You're likely to trigger an avalanche on any steep open slope with wind drifted snow, even open slopes below treeline.  In isolated areas below treeline, the new snow may bury weak snow layers and make avalanches easier to trigger.  

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    A strong frontal system will easily build new wind slabs on Thursday.   Strong to extreme west winds will drift snow at all elevations, including onto open slopes below treeline.  It should be easy to trigger avalanches on lee slopes steeper than 35 degrees by the end of the day.  The new snow and wind will likely come with poor visibility.  Make sure you're not exposed to larger avalanche paths near and above treeline - large natural avalanches are possible.  Thursday is not the day to go exploring at higher elevations.   

    At lower elevations and in more wind-sheltered areas, you may trigger a shallow wind or storm slab on steep unsupported rollovers and in extreme terrain.   Below treeline and in more wind sheltered areas, you may find that fresh and generally shallow storm slabs break more widely than expected and are easy to trigger where they layer over buried surface hoar.   Investigate the new snow/old snow interface by using small test slopes before committing to more consequential terrain.   

     

    (1/4/2023)

    Winds forming reactive drifts near Timberline earlier in the season.  Shooting cracks are a red flag to stay off of steep slopes at any elevation.

    Photo: Joe Dellaporta

Avalanche Discussion

After a few days of great riding conditions on shadier and more wind-sheltered spots,  the storm pattern will pick up and bring plenty of wind over the next 36 hours.  On Wednesday,  surface conditions were quite variable with NW winds drifting snow in the alpine,  rollerballs observed on steep sunny slopes, and dry snow and good snow conditions on cooler slopes at lower elevations.  Forecaster Joe Dellaporta found widespread surface hoar sparkling on the snow surface in these sheltered areas.  We'll see if this layer survives the next round of wind and becomes a weak layer worth tracking in the future. 

Prior to the incoming storm, the Mt Hood Meadows weather station had recorded a storm total of 27 inches (2.23 inches swe) since Feb 26th. On Tuesday morning the Mt Hood Meadows Pro Patrol triggered a few large avalanches (D2) with explosives. One of their bigger results on an ESE aspect at 6200 ft,  broke 18-24” deep and failed just above the new/old snow interface. 

In the following days keep your partners in close sight and give tree-wells a wider buffer than normal. It's deep out there! 

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