Bollettino valanghe

South Coast

Nov 25 – 26, 2017Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

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

In sintesi

Wet, warm weather forecasted for Sunday means the potential for loose, wet avalanches in extreme terrain. Watch for pockets of storm slab in areas that receive snow instead of rain. Very strong winds are forecast Sunday morning at higher elevations.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Be aware that storm slabs may exist in the high alpine. Dial back your terrain selection if you find the snow surface changing from wet snow to new snow as you gain elevation.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1–2
    Rain has saturated the upper snowpack and the potential for loose wet avalanches exists on steep, unsupported terrain features. Even a small loose wet avalanche can gain enough mass to become a big problem.

Confidence

Low - Due to the number of field observations

Weather Forecast

Another warm and wet system will pummel the South Coast on Sunday before freezing levels drop with moderate snow accumulations into early next week.Sunday: Rain during the day (20-30 mm) before the freezing levels drop to 1000m (and possibly as low as 700m) in the evening with 10-15cm snow overnight. Strong to extreme south winds at ridgetop on Sunday morning. Monday: Flurries, accumulation 10-15 cm. Light to moderate southwest wind. Alpine temperature -1. Freezing level 1000 m.Tuesday: Snow, accumulation 20-30 cm. Moderate to strong south wind. Alpine temperature -1. Freezing level 1200m.

Avalanche Summary

No recent avalanches have been reported. However, the recent rain-on-snow event is suspected to have caused a natural, loose wet avalanche cycle. Although natural avalanche activity and human triggering potential has decreased with cooler temperatures, ongoing rain will maintain the potential for loose wet avalanches, particularly in steep, unsupported terrain. Storm slab development is also a concern at high alpine elevations where precipitation may fall as snow accompanied with strong winds.

Snowpack Summary

There is little information on snowpack structure at this time, except that recent heavy rainfall has saturated the upper snowpack at all elevations and washed away much of the snow at lower elevations. Travel below treeline is becoming more and more rugged, with many open creeks and early season hazards.  Up to 30 cm of heavy wet snow may have fallen at the highest elevations (above 1400m) Friday into Saturday.Snow depth varies from 40 - 130 cm for elevations between 900 - 1200m across the region.

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