Bulletin d’avalanche

Lizard-Flathead

Feb 24 – 25, 2017Avalanche Canada
Voir sur la carte
Archivé · expiré 10 years ago

Danger d’avalanche

Sat
Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
Ouvrir la carte complète

Points saillants

Changing winds may transport recent storm snow into deep pockets on several aspects.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Deep storm slabs (50-60cm) may take some time to settle and bond to the old surface. This problem may linger in areas with a hard rain crust below the storm snow.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    2–4
    There have been two natural deep persistent slab releases in the past few days in the Lizard range. Both of these avalanches were on northeast aspects in the alpine, and released to size 3.0 or larger.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Saturday

Weather Forecast

Tonight: Overcast with light west winds, flurries, and alpine temperatures -15. Saturday: Overcast with light snow and periods of intense flurries. Expect 5-10 cm of new snow combined with moderate westerly winds. Sunday: Overcast with light easterly winds and 3-5 cm of new snow, and alpine temperatures -15. Monday: Overcast with flurries and southerly winds.

Avalanche Summary

Explosives control near Fernie resulted in a deep persistent avalanche on Friday; this avalanche was size 2.5 on a north aspect at 2000 metres, and is believed to have released on the mid-December facets. There was a report on Tuesday of a natural avalanche size 3.5 on Mt Hosmer on an East aspect at 2100 metres that appears to have released on or stepped down to the weak deep persistent layer of sugary facets near the ground. On Wednesday we had a report of a size 3.0 avalanche on "Big Steep Mother" bowl on a northeast aspect at 2100 metres in the alpine in the Lizard range. This avalanche appears to have been started by a cornice fall that released a storm slab that then "stepped down" to deeply buried weak facets.

Snowpack Summary

There is now 50-60 cm of storm snow that is expected to settle into a storm slab. This slab sits above a thick rain crust below 1900 m and a generally well settled snowpack. Isolated basal weaknesses may still exist in shallow snowpack areas. These weak areas appear to be on north-northeast aspects in the alpine. If the winds shift direction over the next few days, watch for new wind loading on south-west aspects.

Régions couvertes