Bollettino valanghe

Olympics

Northwest Avalanche Center
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Pericolo valanghe

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

The Olympics will start the day with minimal avalanche hazard, but the danger will increase rapidly as wind loads fresh snowfall onto lee slopes. Actively blowing and drifting snow or fresh, sharp cornices can help you avoid the steep wind-exposed start zones where you might trigger a slab. Anticipate rapidly increasing avalanche danger as snow and wind intensify further during the evening hours.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    The first significant snow storm in a long time will ramp up early Sunday, intensifying as the day progresses. We expect 6" of snow above around 3000 ft by the end of the day. Moderate winds should drift the incoming snow to form slabs that may be thin and harmless to start the day but will increase in depth and extent. Runnels on the old snow interface will provide a good indicator of the progression of the problem. Once the new snow smooths out the terrain, assume you can trigger an avalanche in wind-drifted snow. Look for actively blowing and drifting snow, textured snow, or lens-shaped pillows to steer around slopes steeper than 35 degrees if you suspect the slope may be wind loaded. If your pole probing identifies more than 6" of fresh snow in your terrain, this problem transitions to a storm slab and you should avoid all slopes steeper than 35 degrees.

    Example: Wind textured snow surfaces like this often indicate wind loading on nearby slopes. 

    Photo: Shane Robinson

Avalanche Discussion

Fresh will fall on bare ground on many slopes that have been exposed to sun, wind, and rain over the last several months of mild weather. This creates non-avalanche hazards more typical of "early-season," including shallowly submerged rocks, branches, tree limbs, and dirt. Assume that wind-exposed slopes and many W-S-SE aspects have patches or entire slopes melted out to the bare ground. Descend with caution. 

Hurricane Ridge picked up a skiff of new snow late Friday, but that snow probably melted into the snowpack as temperatures bumped above freezing under mostly cloudy skies on Saturday.

NWAC forecasts and NPS professionals touring in the Maggies area of Hurricane Ridge on Friday encountered a spring-like day at Hurricane Ridge with temperatures climbing into the mid-30s yielding softened slushy skiing. On southerly aspects, they found a summer-like fully transitioned snowpack (see associated photo)  that was discontinuous and up to 40 inches deep. Snowpacks on northerly aspects were significantly better preserved with 5-10 ft of snow that was well along in the spring transition but still maintained a more distinct structure which you can observe in the snowpit photo from the Bowling Alley.  Avalanche hazards were minimal given how much warmth the snowpack has absorbed with sun and rain as well during recent weeks. Cornices have partially shed with the warmth and rainfall in recent weeks.

2021-22 Forecast Schedule: Avalanche danger ratings will be issued for the Olympics every Friday through Sunday and during mid-week holidays. During the week when the Hurricane Ridge road is closed, forecast information will be updated daily to include expected conditions and relevant travel advice under the No Rating label.

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