Bollettino valanghe

Stevens Pass

Apr 8 – 9, 2015Northwest Avalanche Center
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Archiviato · scaduto 11 years ago

Pericolo valanghe

Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole

In sintesi

The main avalanche problem should be possible small loose wet avalanches on solar slopes. Use caution on slopes below cornices and on ridges where it can be hard to know if a cornice is present.

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1

Detailed Forecast

The weak shortwave, moisture and instability should continue to linger over Washington on Thursday. So expect cumulus and a slight chance of showers will be forecast again Thursday afternoon mainly over the central and south Cascades on both sides of the crest. This weather will not greatly change snow conditions.

It's April, so be aware of the increased sun effects reaching more aspects and affecting the snow surface fairly quickly. Loose wet avalanches involving shallow amounts of recent storm snow will be possible Thursday, especially in any direct sun on solar slopes.  

Cornices won't be highlighted as an avalanche problem due to the cool weather but use caution on slopes below cornices and on ridges where it can be hard to know if a cornice is present.

Snowpack Discussion

A large weak upper trough moved over the Northwest last weekend through early this week. This caused some light snow at times west of the crest with low snow levels. Freezing levels have been very low in April compared to most of the winter, averaging about 4-5000 feet.

Backcountry reports from across the Cascades near and above treeline indicate cool, preserved snow on non-solar aspects with limited wind effects, gradual settlement and generally good bonds to the previous crust.  On solar aspects, sun breaks have caused only small loose wet avalanches and crusts.

Some large cornices continue to be reported along ridges especially in the north Cascades.

A weak shortwave, moisture and instability is causing cumulus and showers Wednesday mainly over the central and south Cascades on both sides of the crest.

Snowpack problems west of the crest should remain in the upper or surface layers. The mid and lower snowpack west of the crest consists of layers of stable consolidated rounded grains or melt forms and crusts from multiple warm periods this season. Many areas at lower elevations do not have enough snow to cause an avalanche danger.

Regioni coperte