Bollettino valanghe

Kootenay Boundary

Mar 13 – 14, 2018Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 9 years ago

Pericolo valanghe

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

In sintesi

Wednesday is a day of transition. The snowpack will see a final test of warm air and light rain before cooling temperatures have a stabilizing effect.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2
    Wind slab problems will be in transition on Wednesday. More recent slabs may remain sensitive to human triggering around high north aspects and areas that don't see rainfall. Cooling temperatures should lock everything to the surface by end of day.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1.5–3
    Weak layers exist 40-100 cm below the surface, including surface hoar on north-facing terrain and sun crusts on south-facing terrain. These layers will just be beginning to recover from warm temperatures on Wednesday.

Confidence

Moderate -

Weather Forecast

Wednesday: Cloudy with scattered wet flurries bringing 5-10 cm of new snow. Moderate to strong south winds. Freezing level dropping from about 2500 to 1500 metres over the day. Alpine high temperatures around 0.Thursday: Mainly cloudy. Light northwest winds. Freezing level to 1600 metres with alpine high temperatures around -2.Friday: Cloudy with flurries beginning in the evening. Light northeast winds. Freezing level to 1600 metres with alpine high temperatures of -3.

Avalanche Summary

Avalanche activity through the end of the weekend into Monday focused on a natural solar induced loose wet avalanche cycle on south and west aspects in the alpine an treeline to size 2. On Friday reports indicate numerous size 2-2.5 natural and explosive controlled storm snow avalanches running on all aspects in the alpine and at tree line. There were also several skier triggered storm slab avalanche size 1.5-2 both Friday and Saturday on north aspects in the alpine and tree line.

Snowpack Summary

Light rain transitioning to wet flurries should bring 5-10 cm of new snow by Wednesday afternoon. This new snow will accumulate on a variable surface of crust and moist snow.Last week's snow has settled and been redistributed by predominantly west and southwest wind on upper shady aspects or has become moist or wet and/or refrozen (depending on the time of day) on slopes facing the sun. On sheltered northerly aspects it may be sitting on a layer of surface hoar.A mix of weak layers exist 50-100 cm below the surface, including small surface hoar on shady aspects and a crust on solar aspects. These layers have consistently been reactive in snowpack tests, suggesting they could potentially remain reactive to human triggers as well. Deeper weak layers that formed in January and December have gained strength and gone dormant at this time. They include several surface hoar and facet layers 1 to 2 m below the surface and a crust/ facet interface near the base of the snowpack.

Regioni coperte