Bollettino valanghe

South Rockies

Apr 13 – 14, 2021Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 5 years ago

Pericolo valanghe

Thu
Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

Danger will progressively increase as the days get warmer and sunnier. Read more in this Forecasters' Blog.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Watch for pockets of unstable snow in steep alpine terrain.

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    2–2.5

    Strong solar radiation and warming may trigger the large cornices that hang over ridgelines.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–1.5

    Expect small wet loose avalanches to occur naturally on solar aspects when the sun comes out.

Confidence

Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

TUESDAY NIGHT: Clear skies, 40 km/h northeast wind, freezing level drops to valley bottom with treeline temperatures dropping to -7 C.

WEDNESDAY: Mix of sun and cloud, 40 km/h northeast wind, freezing level to 2000 m with treeline temperatures around -1 C.

THURSDAY: Sunny with a few clouds, light northeast wind, freezing level climbing to 2300 m with treeline temperatures reaching +1 C.

FRIDAY: Sunny, light northeast wind, freezing level climbing to 2500 m with treeline temperatures reaching +4 C.

Avalanche Summary

Recent reports are limited to a few small dry loose and wet loose avalanches on Sunday and Monday. Warm sunny weather this week will increase the size and likelihood of wet loose avalanches and cornice falls.   

Prolonged warming may increase the sensitivity of deeply buried layers later this week, although there is a fair bit of uncertainty about how likely this is in the South Rockies region. There have been some notable slab avalanches reported to the north of the region over the last few days including a skier triggered avalanche in Kananaskis Country on Saturday (see reports here and here) as well as a natural deep slab avalanche in Kootenay National Park on Tuesday (see photo here). These avalanches provide a good reminder of why it's good to be extra cautious during the heat of the day this time of year.

Snowpack Summary

North alpine terrain has roughly 30 cm of settling powder with wind slabs possible on steep exposed slopes. Other terrain is undergoing a melt-freeze cycle with successive days of warm sunny weather. The lower snowpack is generally strong and settled, however weak snow at the base of the snowpack may become a concern later this week when things really warm up. The snow line is creeping up to higher elevations, so some common access points are now snow free.

Terrain and Travel

  • Avoid exposure to sunny slopes, especially in the afternoon.
  • Cornices become weak with daytime heating.
  • Loose avalanches may start small but they can grow and push you into dangerous terrain.
  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.

Regioni coperte