Lawinenlagebericht

Northwest Coastal

Mar 19 – 20, 2023Avalanche Canada
Auf der Karte ansehen
Archiviert · abgelaufen 4 years ago

Lawinengefahr

Tue
Wed
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
Vollständige Karte öffnen

Kernpunkte

Buried surface hoar continues to be reactive, especially in wind loaded features.

Stick to conservative terrain free from overhead hazard, and watch for signs of instability increasing with daytime heating.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2.5

    Storm snow has been redistributed by southwest winds into deeper deposits, primarily found on north and east facing terrain features.

    A buried layer of surface hoar is increasing the reactivity and propagation of wind slabs. Avoid sheltered and shaded slopes where surface hoar is more likely to be found. On other aspects, this layer is present as a melt freeze crust which has also produced avalanche activity.

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2

    With freezing levels remaining elevated overnight watch for an increase in avalanche hazard when the sun directly impacts slopes tomorow. Pinwheeling and recent avalanches are signs of a weakening upper snowpack.

Confidence

Moderate

Avalanche Summary

On Saturday, numerous loose wet to size 1.5 were observed in steep, rocky solar terrain. Several natural storm slab avalanches were observed up to size 2.5, likely triggered by the sun or cornice failure. A few skier triggered, size 1, avalanches were reported. These avalanches released on a weak layer of surface hoar underneath the storm snow.

Snowpack Summary

Southwest winds have created reactive deposits of wind slab on north to east facing terrain features at ridge top. A melt freeze crust or moist snow exists on the surface at low elevations and on sun affected slopes.

A weak layer of surface hoar is found 20-50 cm down in sheltered terrain. On solar aspects, this layer appears as a melt-freeze crust. This layer continues to be reactive to skier traffic.

A second weak layer of surface hoar and/or faceted grains may be found about 60 cm deep, particularly on shaded aspects near treeline.

The remainder of the snowpack is consolidated and strong.

Weather Summary

Sunday Night

Mainly cloudy. Strong southeast winds at ridgetop. Treeline temperature 0°C. Freezing levels remain around 1400 m through the night.

Monday

Mainly sunny with cloudy periods. Moderate southeast winds at ridgetop. Treeline temperature +1°C. Freezing levels 1500 m.

Tuesday

Mix of sun and cloud. Moderate southeast winds at ridgetop. Treeline temperature +1°C. Freezing levels 1500 m.

Wednesday

Mainly clear. Moderate southwest winds at ridgetop. Treeline temperature -2°C. Freezing levels 1200 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be carefull around freshly wind loaded features.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Abgedeckte Regionen