Bollettino valanghe

South Coast

Feb 27, 2018Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

Wed
Thu
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
Apri la mappa completa

In sintesi

10 to 20 cm of new snow Tuesday will add to the 55 cm that fell over the weekend. The snow rests on a mix of old surfaces and storm slabs may remain sensitive to human triggering. Start with simple terrain and gather info before stepping out.

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–3
    Large cornices have formed along ridgelines. Cornices are inherently unstable, unpredictable, and demand respect, especially if the sun is shining.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–2.5
    10 to 20 cm is expected Tuesday which adds to the 55 cm of snow that fell over the weekend. This snow rests on old wind slabs and a crust on solar aspects, but little is known about the bond. Storm slabs may remain sensitive to human triggering. 

Confidence

Low - Due to the number of field observations

Weather Forecast

A weak upper trough Tuesday should deliver a good shot of precipitation and wind before a vigorous low makes landfall on Wednesday which has potential to bring significant precipitation. Unfortunately the weather models have not yet agreed on a solution with regard to track and intensity, but there will likely be less uncertainty as we get closer to Wednesday. Stay tuned for more details. TUESDAY: Overcast, freezing level around 500 m, moderate to strong northwest wind, 10 to 20 cm of snow.WEDNESDAY: Overcast, freezing level around 750 m, potentially strong to extreme south/southwest wind, latest model run shows about 10 cm of snow. Stay tuned for more details. THURSDAY: Scattered cloud cover, freezing level around 1000 m, light southeast wind, trace of snow possible.

Avalanche Summary

No new activity to report from Saturday or Sunday. The new snow was reactive to skier activity on Friday, producing small (size 1) dry loose and storm slabs. See this MIN report that talks about storm slabs 10 to 40 cm in depth here.

Snowpack Summary

Around 30 to 40 cm of storm snow fell on Friday and another 10 to 15 cm of snow fell Saturday night into Sunday. Both of these storms had strong southerly winds. All of this snow rests on previously wind-affected surfaces and a sun crust on southerly aspects.A hard rain crust that extends into alpine terrain is buried about 60 to 100 cm. Reports suggest the snow has a poor bond to the crust with test results showing sudden planar characteristics and a Rutschblock 2 (the whole block failing after standing on it). Monitor the bonds of the new snow as well as the bond of the snow directly above the buried crust. There are no substantial layers of concern below the crust.Also make note of cornices at ridgeline. Variable winds in the past month have produced cornices on all aspects. They will become touchier as they grow in size, as temperatures rise, and as the sun packs a strong punch on clear days. Stand well back of them!

Regioni coperte