Bulletin d’avalanche

Lizard-Flathead

Mar 18 – 19, 2018Avalanche Canada
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Archivé · expiré 9 years ago

Danger d’avalanche

Tue
Wed
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré

Points saillants

Forecast snow fall amounts are uncertain: If you see more than 20 cm of new snow, it's time to dial back your terrain choices and take a close look at how the new snow is bonding to the old snow surfaces.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–2
    New snow on Sunday night may not bond well to underlying surfaces. Dry loose sluffs may run fast and far, especially if the new snow sits on a slippery melt-freeze crust.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Monday

Weather Forecast

Snow fall totals are uncertain Sunday evening into Monday, with 5cm on the low end and 20 cm being the upper end of forecast amounts.  SUNDAY NIGHT: Snow. 5-15cm likely. Overnight lows near -5 Celsius. Light southerly winds.MONDAY: Cloudy with lingering flurries (up to 5 cm additional snow). Moderate westerly winds. Alpine temperature +1 C. Freezing level rising to 1600 m.TUESDAY: Cloudy with sunny breaks. Light westerly winds. Alpine temperature +2 C. Freezing level 1700 m.WEDNESDAY: Cloudy with sunny breaks. Light to moderate westerly winds. Alpine temperature +2 C. Freezing level 1800 m.

Avalanche Summary

On Friday and Saturday, several small wet loose avalanches to size 1.5 were reported on sunny aspects at all elevations. A size 1.5 natural cornice failure was also reported on a high north east facing ridge line, which did not trigger any slabs below.

Snowpack Summary

The last precipitation fell late last week, delivering snow to higher elevations and rain down low. Since then, the sun came out on Friday and Saturday, creating a melt-freeze crust on sunny aspects, but still leaving dry snow to be found on north aspects above 1300m.Thursday's snow fell on a previous melt-freeze crust produced by warm air temperatures, sun, and rain. The crust exists everywhere except for possibly shady aspects at high elevations. Deeper in the snowpack, the mid-December and late-November weak layers are composed of crusts and sugary facets, which are down 150-300 cm. These layers have been dormant but may be awoken by a large trigger, such as a cornice fall, or by humans traveling in thin-to-thick snowpack areas.

Régions couvertes