Bollettino valanghe

Mt Hood

Feb 9 – 10, 2019Northwest Avalanche Center
Vedi sulla mappa
Archiviato · scaduto 8 years ago

Pericolo valanghe

Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Apri la mappa completa

In sintesi

You are likely to trigger a storm slab where recent moderate winds have stiffened snow surfaces or where settlement and sunshine consolidate the thick storm snow layer into a slab. The slab sits on heavily faceted old snow which will increase slab propagation to produce large avalanches.

Problemi valanghivi

  • Storm Slabs

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

    Plenty of new snow sits in the terrain and will be most likely to trigger where it has formed a slab. Large and dangerous slabs are likely to form where (1) recent moderate winds which transported low density snow into a soft slab or where (2) settlement or the sun consolidates snow into a slab. The consolidation in many cases may occur during the day on Sunday, leading to increasingly reactive conditions as the day wears on. Travel in less wind-affected terrain, using visual clues such as recent soft cornices and textured snow surfaces to identify these problematic areas. Use small test slopes to gauge the storm slab problem. If you experience sudden settlement of the upper snowpack or cracking of the snow surface, you have a dangerous slab problem in your area. If you’re unsure whether this problem exists, it is best to choose supported terrain less than 35 degrees.

Discussion

Snow and Avalanche Discussion

9-14” of storm snow fell at low density from mid-day Friday through the end of the day Saturday. The storm snow buried surface hoar or near surface facets near and below treeline or a crust BTL and on sun-affected aspects. Areas that head weak underlying snow are more likely to produce avalanches Sunday.  Loose dry avalanches will continue to be a concern in very steep terrain that isn't wind affected. Keep this in mind around terrain traps; you don't want a small but fast moving avalanche to take you on an unexpecting ride into trees or over a cliff.   

Snowpack Discussion

Regional Synopsis coming soon. 

Regioni coperte