Bollettino valanghe

South Rockies

Apr 7 – 8, 2015Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 11 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

Daytime warming and solar radiation will be driving the avalanche danger over the next few days. Watch for conditions that change with aspect, elevation and time of day.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Lingering wind slabs in the alpine may be sensitive to human triggers. Watch for triggering in the lee of ridge crests and in gullies.

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–4
    Large cornices at ridgetop may fail under the weight of a human-trigger. As spring conditions evolve, remember that destructive cornice falls become more likely during periods of warming and solar radiation.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2
    Over the next few days, watch for pushy loose wet avalanche activity on sun exposed slopes. Loose wet avalanches are most likely in areas where dry snow is exposed to solar radiation for the first time.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Generally sunny skies are expected for the forecast period as a dry ridge sets up over the region. Increased cloud and light snowfall are possible on Friday evening. Ridgetop winds should remain light for Wednesday and Thursday, and then become strong from the southwest by Friday night. Daytime freezing levels should hover around 2000m.

Avalanche Summary

Observations are becoming more limited as we enter into spring. If you're out in the mountains, please consider posting your observations to our webpage using the Mountain Information Network. With freezing levels rising and lots of sun expected on Wednesday, lots of natural sluffing is expected from steep sun-exposed slopes, especially in areas where cold, dry snow is exposed to solar radiation for the first time. Cornices will become weaker than they have been for the last week and may fail naturally. Wind slabs in the alpine may be sensitive to human-triggering. Reverse loading may have occurred and wind slabs should be expected on a variety of aspects.

Snowpack Summary

10-30cm of recent snow overlies a widespread and supportive melt-freeze crust. Recent strong winds may have redistributed the surface snow resulting in wind slab formation in the alpine and exposed areas at treeline. Large cornices exist in the alpine and may become weak with daytime warming. The mid-March rain crust is down 35 to 70cm and has shown a good bond with snow above. Old persistent weak layers are still intact in the mid and lower snowpack and there may be potential for these layers to wake up with a big cornice fall, sustained warming and/or a significant rain event.

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