Bollettino valanghe

Northwest Coastal

Apr 18 – 19, 2012Avalanche Canada
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Archiviato · scaduto 14 years ago

Pericolo valanghe

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

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–4
    New wind slabs may develop at upper elevations with forecast snow and wind. Be alert for these behind ridges and terrain breaks.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–5
    Loose wet avalanches are most likely during periods of warming from rainfall or sunshine. These can push you around, entrain mass and become surprisingly large.

  • Wet Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–7
    Warm temperatures or rain may continue to weaken the snowpack, leading to full-depth releases. Avoid traveling on or underneath any slopes which sport glide cracks. Glide cracks have been releasing all week, initiating large-very large avalanches.

Confidence

Fair - Intensity of incoming weather is uncertain on Friday

Weather Forecast

A low pressure system over the Gulf of Alaska is moving a strong Westerly flow through the forecast period. This will bring a mix of frontal systems, and ridges. These fast moving systems will be hard to time, and they'll bring light-moderate amounts of precipitation accompanied by periods of clearing and sunshine. A building ridge will develop Friday through the weekend. Dry conditions, warming temperatures, and intense solar radiation may persist. Moderate precipitation expected in the evening (10-15 mm). Ridgetop winds moderate from the SE. Freezing levels 140 m. Friday: Moderate- heavy (25 mm) during the day. Ridgetop winds light-moderate from the SW. Freezing levels steady 700 m. Saturday: Dry, skies clearing. Ridgetop winds light from the SE. Freezing levels rising to 1200 m.

Avalanche Summary

On Tuesday a large explosive control mission reported 10 size 2-2.5, and 1 size 3 avalanches. Slopes targeted were E-SE, 1500 m and below. On Monday, numerous natural glide avalanches were reported up to size 3. Several loose wet avalanches up to size 2.5 that ran to ground have also been observed in response to warming from rainfall and sunshine.

Snowpack Summary

Spring-like conditions exist through the region. Melt and frozen surfaces continue on all aspects. Slopes that start to become wet, and slushy should be avoided because loose wet avalanches may occur. Lately, a lack of consistent overnight freezing has left the snowpack weak and unconsolidated, even isothermal below 1100 m, although some re-freezing has been reported in some areas. Glide cracks have opened up and pose the threat of large, full-depth releases, especially on steep rocky terrain features at low elevations. Large cornices loom, and ice cliffs pose a threat from above. For more information on Spring Conditions and ways to mitigate risk, please visit the new Forecasters Blog Post.

Regioni coperte