Bollettino valanghe

Jasper

Jan 13 – 14, 2018Parks Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

Sun
Mon
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

Be on your game for the weekend. Persistent slabs in exposed areas make it difficult to travel with confidence. Watch for increasing west winds that may further develop windslabs and rising temperatures that may allow for easier triggering.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    The new snow has already formed thin, spotty slabs even with the limited amount of wind we have seen so far. These slabs sit on freshly buried, weak facets and surface hoar in some areas. Watch for these slabs to develop with more wind Saturday.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–3
    New snow covers pockets of old slab sitting on weak, faceted snow that lacks strength, and may fail, to mid-pack depths. Treat all wind exposed areas with care but approach larger, uniform features and thin areas with caution.

  • Loose Dry

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–2
    New snow covers a facetted/weak upper snowpack in sheltered areas. Be cautious in very steep terrain and in confined features where a small sluff could build mass. Even light winds were triggering these events along alpine ridges Thursday.

Weather Forecast

A ridge will reach the coast Friday and bring warmer, moist air to the  Jasper region through the weekend. Alpine temperatures will be inverted and reach -6C on Saturday with a chance of a few flurries in the AM, watch for West winds to increase to 15km/h. An increase in the freezing levels to 2200m is called for Sunday as West winds to 20km/h.

Snowpack Summary

10-15cm of recent snow has blown into thin windslabs TL and above. Old slabs 10-30cm deeper sit on a weak layer of facets or surface hoar TL and above. In sheltered areas this new snow sits a faceted upper snowpack at all elevations. A strong mid snowpack crust is providing strength but is weakening. The lower snowpack continues to lose strength.

Avalanche Summary

Yesterday, besides a few small windslabs and sluffs from alpine terrain, a sz 2 slab 20cm deep and 50m wide likely failed on the Dec 18 persistent layer. This shallow slab ran a few meters before stepping down another 40 cm (likely through weak facets to the November 27 midpack crust). All of this ran 70m to a cliff triggering a small slab below.

Confidence

Due to the number of field observations on Friday

Regioni coperte