Bollettino valanghe

Northwest Coastal

Feb 28 – 29, 2012Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 15 years ago

Pericolo valanghe

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

In sintesi

The snowpack is tricky to predict at the moment. Backcountry travel requires local knowledge, extensive experience and training. Please read the new Forecaster's Blog Post.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely - Very Likely
    Dimensione
    1–4
    Moderate winds and new snowfall have created new and reactive wind slabs on lee terrain. Recent outflow winds have compounded this problem with reverse loading.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–6
    The persistent interface from mid February remains a concern. Large avalanches occurred on Sunday, with these layers being suspect.

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

A continued unsettled weather pattern exists. Wednesday: Light snow amounts 5-10 cm. Ridgetop winds 30km/hr from the East. Treeline temperatures near -8. Thursday: A Pacific frontal system will start to affect the region bringing light snow amounts during the day, and light-moderate amounts later that night. Ridgetop winds will be strong from the West. Treeline temperatures near -8. Friday: Light-moderate snow amounts. Ridgetop winds moderate from the West. Treeline temperatures near -5. Freezing levels may rise to 1000 m, and then drop to valley bottom at night.

Avalanche Summary

On Sunday reports of large loose power sluffing, entraining significant amounts of recent storm snow on N-NE aspects up to size 2.5. Natural activity has seemed to taper off, but I suspect that conditions may still be ripe for rider triggers; especially wind loaded pockets and sheltered areas where buried SH layers may still linger.

Snowpack Summary

Over the weekend new snow up to 25 cm fell. Generally, this has left us with a 45-60 cm sitting above the mid February layers. Recent clear, sunny skies have created a sun crust on south facing terrain into the alpine.The aforementioned mid February layers consist of a strong melt freeze crust below 1000m, buried wind slabs near treeline and higher into the alpine while between these elevations the interface varies wildly from facets, surface hoar, sun crust or wind press. The surface hoar seems to be spotty but is responsible for much of the recent avalanche activity. Recent testing done on the SH layers produced CTM SP down 70-100m. With the additional wind loading, pockets as deep as 90cm are possible on lee features. Recent outflow winds have exacerbated the wind slab issue, building reactive slabs on south facing terrain features. The mid and lower snowpack is generally well settled and strong.

Regioni coperte