Bulletin d’avalanche

Lizard-Flathead

Feb 9, 2017Avalanche Canada
Voir sur la carte
Archivé · expiré 10 years ago

Danger d’avalanche

Thu
Fri
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
3 · Marqué
Ouvrir la carte complète

Points saillants

A Special Public Avalanche Warning Applies for this Region.There is uncertainty with forecast snow amounts and the freezing level Wednesday night into Thursday. Danger ratings are based off the higher end of snow estimates and a higher freezing level

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    2–3
    Additional new snow, warmer temperatures and wind have created touchy new storm and wind slabs. Previously buried weakness beneath the storm snow may increase the reactivity of these storm slabs.

Confidence

Moderate - Freezing levels are uncertain on Thursday

Weather Forecast

THURSDAY: Snow, accumulation 20-40cm / Moderate to strong southwest winds / Alpine temperature -2 with a freezing level of 1600mFRIDAY: Flurries, accumulation 5-10cm / Moderate to strong southwest wind / Alpine temperature -5 with a freezing level of 1400mSATURDAY: Cloudy with isolated flurries / Moderate west wind / Alpine temperature -9More details can be found on the Mountain Weather Forecast.

Avalanche Summary

Additional new snow, warmer temperatures and wind on Thursday are expected to give a spike in avalanche activity. Previously buried surface hoar, facets, and/or a sun crust may increase the reactivity and propagation propensity of new storm slabs.On Monday, several natural storm slab avalanches up to size 2.5 were observed. Explosives and skiers also triggered storm slab avalanches up to size 2 on Monday and Tuesday. These recent avalanches have had a typical slab thickness of 30-60 cm. On Sunday, natural and human triggered avalanches up to size 3 were observed on all aspects and elevations above around 1500m.

Snowpack Summary

Another 20-30cm of snow on Wednesday night through Thursday will add an additional load to the 60-80cm of storm snow accumulated last weekend. Strong shifting winds redistributed the previous storm's snow in exposed terrain forming touchy wind slabs. These wind slabs are now obscured by the latest round of snowfall. The combined accumulation of multiple storms' snow overlies a highly variable old surface which included wind affected surfaces, a layer of surface hoar in sheltered areas, facets, and/or a thin sun crust. Recent reports suggest a poor bond between the new snow and the old surface. The mid and lower snowpack are generally well settled and stable but isolated basal weaknesses may exist in shallow snowpack areas.

Régions couvertes