Bollettino valanghe

Banff Yoho Kootenay

Jan 26 – 27, 2018Parks Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

Sat
Sun
Alta quota
4 · Forte
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
Apri la mappa completa

In sintesi

We have reached the tipping point for avalanches in most of the region, and a natural cycle occurred Thursday. We may see a decrease in natural activity for Friday, but slopes are primed for human triggering. Time to step way back.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2
    With up to 75cm of snow over the past 9-days there is plenty of wind slab development available to be blown into touchy windslabs which should be anticipated in alpine and treeline areas.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3
    There are 3 weak layers in the upper snowpack: Jan 16, Jan 6, and Dec. 15. All are a mix of sun crust, surface hoar and facets depending on your aspect and elevation. Avalanches are occurring on these layers

Weather Forecast

A cooling trend for Friday with alpine highs of -16C, and valley bottom highs of -12C (-5C on the East slopes like Banff). Only 1-3cm of snow is expected with Westerly alpine winds in the 30-40kmh range.

Snowpack Summary

55-75cm of snow has fallen over the past 9-days creating a lot of loose snow on the surface. Alpine winds have distributed this into leeward areas with wind slabs up to 1m thick. Three persistent weak layers lurk in the upper half of the snowpack: Jan 16 down 20-40cm; Jan 6 down 30-50cm; Dec15 down 40-80cm giving easy-mod test results.

Avalanche Summary

We have hit the "tipping" point over the weak layers mentioned above and there is a natural avalanche cycle to size 3 occurring. Some avalanches are occurring in the new snow only, with some stepping down to the numerous weak layers below. Explosive control on Bosworth produced results to size 2 within the new snow. 

Confidence

Regioni coperte