Bulletin d’avalanche

Lizard-Flathead

Feb 15, 2017Avalanche Canada
Voir sur la carte
Archivé · expiré 10 years ago

Danger d’avalanche

Wed
Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
Ouvrir la carte complète

Points saillants

Wednesday's danger ratings are based on overcast skies. If the sun makes an appearance, consider the avalanche danger to be higher than posted.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3
    Most of our upper snowpack is essentially a storm slab. Its bond to the underlying snow is improving, but forecast warming may increase the likelihood of an avalanche. Watch for increased reactivity in high elevation wind-affected terrain.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2
    Warm temperatures and possible solar radiation will promote loose wet avalanches on Wednesday, especially in steep terrain. Watch for conditions that change with aspect, elevation and time of day.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Wednesday

Weather Forecast

Wednesday: Clear skies in the morning with increased cloud throughout the day / Strong southwest winds / Freezing level at 2500mThursday: 5-10cm of new snow / Strong southwest winds / Freezing level at 2100mFriday: Clearing skies / Light southwest winds / Freezing level at about 1800m

Avalanche Summary

Sunday's reports are limited to a single MIN post revealing an impressive Size 3 avalanche in the Little Sands area. This avalanche, along with a number of others observed the same day, appears to have been triggered by solar warming. While the age of the avalanche in the photo is uncertain, backcountry travelers should be ready for ongoing warming to produce these types of avalanches over the coming days.

Snowpack Summary

Strong ridgetop winds have left surfaces wind-scoured and pressed leaving very little in the way of ski penetration at treeline and above. Below around 1700 metres you'll likely find a breakable rain crust. Beneath these variable surfaces lies an estimated metre of storm snow from storms over the past two weekends. The upper half of this layer was deposited as heavy, moist snow, while the lower half is considerably drier and less dense. This 'upside down' storm snow layer lies above a range of previous surfaces that includes wind affected surfaces, a layer of surface hoar in sheltered areas, facets, and/or a thin sun crust. The bond between this earlier storm snow and the old surface is suspected to be improving slowly while hard conditions at the current surface may be diminishing the effect of human triggering. The mid and lower snowpack are generally well settled and stable but isolated basal weaknesses may exist in shallow snowpack areas.

Régions couvertes