Bulletin d’avalanche

Jasper

Mar 17 – 18, 2017Parks Canada
Voir sur la carte
Archivé · expiré 10 years ago

Danger d’avalanche

Sun
Mon
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
5 · Très fort
Ouvrir la carte complète

Points saillants

Warm temperatures and upwards of 30cm of storm snow is on its way. Avalanche danger will remain at a seasonal high until this passes.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    2–3
    40cm of storm snow over the week has formed a dangerous windslab. Wide crowns up to 2m deep have been seen from Maligne to Parkers area. Strong to extreme SW winds and warm temps will keep this layer very active.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1–3
    Rain to treeline and warm temperatures will produce numerous avalanches of this type. Some of these will step down to ground producing full path releases.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    2–4
    The widespread observations of large and deep avalanches indicates strongly that many of these events are from this instability. Increased loading and warm temperatures will keep this layer active.

Weather Forecast

Overnight at the Icefields 5 cm of snow, winds 40 km/h W. Freezing level at valley bottom. Saturday 25cm of snow mostly in the south of the region and at higher elevations. Ridge wind SW 25 km/h gusting to 75 km/h. Freezing level 2100 metres with rain in the townsite. A clearing and cooling trend starts Sunday afternoon, moderate SW winds.

Snowpack Summary

Upwards of 45cm of snow has fallen this week. SW winds are building a reactive wind slab at treeline and above. The mid-pack consists of persistent slab layers intermixed with weak facets. The base is weak facets, depth hoar, and an ice crust from November. A temperature crust exists up to 2000 m.

Avalanche Summary

Numerous large natural avalanches (class 3) were observed from the Maligne area to the icefelds at Tree Line and above. These slab avalanches are failing at varied depths; from recent storm snow to deeper older instabilities. Warm temperatures and precipitation will keep the landscape dangerously active.

Confidence

Freezing levels are uncertain

Régions couvertes