Bulletin d’avalanche

Waterton Lakes

Dec 31, 2016 – Jan 3, 2017Parks Canada
Voir sur la carte
Archivé · expiré 10 years ago

Danger d’avalanche

Sat
Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
Ouvrir la carte complète

Points saillants

Deja Vu for Saturday - new snow is blown around, creating Wind Slabs lee to strong South-West winds. Sunday sees an Upslope switch, with new snow being reverse loaded by North-East winds. Watch for Wind Slabs on both sides of ridges Sunday onward.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    These will be found on North and East aspects on Saturday, with lots of recent snow available as fetch. The main problem will move to immediate lees on South and West aspects on Sunday and Monday, as wind directions reverse to the North-East.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3
    Nearby areas have seen these failing in the midpack facets in thicker areas and in loose sugary facets near the ground in thinner areas. They are most likely to be triggered in thin rocky areas, with variable snowpack depth.

Weather Forecast

Saturday: Increasing cloud cover, with Strong Westerly winds easing late afternoon . Temperatures steady around -10.Sunday: Overnight switch to cold North-East winds (Strong in the Alpine, Moderate at Treeline) brings heavy snowfall in the early hours, tapering through the day. -20 at treeline.Monday: Frigid, Moderate North-East winds, flurries.

Snowpack Summary

New snowfall will form Wind Slabs lee to Strong SW winds on Friday night, then again lee to NE winds during Sunday. These cover hard Persistent Slabs, over facets in the middle and bottom of the snowpack. The distribution and sensitivity of these varies greatly, even across each slope. The snowpack is weakest in shallow and/or wind exposed areas.

Avalanche Summary

On Tuesday/Weds, shooting cracks and whoomphing were observed Below Treeline. One large avalanche noted from an Alpine lee slope.On Friday, several small Storm Slab and Wind Slab avalanches were observed in new storm snow, primarily on North and East aspects, at Treeline and Alpine elevations.Natural activity is possible on lee slopes Sat-Sun.

Confidence

Forecast snowfall amounts are uncertain on Sunday

Régions couvertes