Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
1 · Debole
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Dry and mild weather will continue throughout most of the zone on Thursday. Be prepared for variable travel conditions and have the right equipment to keep you from slipping and falling. If you’re going to find an avalanche, it should be on steep sunny slopes once the surface has softened.

Problemi valanghivi

  • Loose Wet

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

    Slopes that see direct sunshine and are sheltered from cool east winds are the most likely location for small Wet Loose avalanches to occur on Thursday. These slopes may be firm and supportable first thing in the morning before the sun has a chance to soften them and create the conditions needed for these avalanches. Don't get caught off guard by one of these slides and get pushed into a terrain trap such as a cliff or gully. If you find that you are sinking into wet snow past your ankle, you’ll know that it’s time to be leery of sunny slopes over 35 degrees.

    (1/24/2022)

    Checking how deep you sink into the snow with your boot is a great way to monitor changing surface snow conditions. Sinking past your ankle, like this, should let you know it may be time to go find more frozen snow. 

    Photo: Andy Harrington

Avalanche Discussion

Our spring-like weather and snowpack structure will persist on Thursday. NWAC weather stations indicate that recent temperatures on the volcanoes have been in the 50s during the day, while stations closer to the crest have been reaching the 40s. At some stations, temperatures have not been dipping below freezing at night, but long clear January nights have allowed surfaces to freeze as longwave radiation is lost to outer space.

In areas prone to east winds, you could find that these cool breezes are helping to delay sunny slopes from warming up compared to recent days. In areas that aren’t as prone to east winds or are more wind-sheltered, you should continue to expect firm surfaces early in the morning that soften throughout the day due to the sun’s input. Keep an eye out for sagging cornices or large cracks in the snowpack that could indicate that slopes are ready to drop large chunks of snow and ice due to the sun’s warmth. Choose travel routes that put plenty of space between you and these unpredictable hazards.

The extended diurnal spring cycle has left us with a firm surface crust with melt forms and smaller melt-freeze crusts below in many locations. The thickness of the crust varies across the zone and as you travel, you may find variable surface conditions depending on aspect, elevation, or time of day. This includes sun softened snow, pockets of wind-deposited snow, breakable crust, or firm and icy surfaces. We do not currently have any layers of concern deeper in the snowpack that we are tracking. 

Dealing with these variable surfaces may be the biggest hazard you encounter on Thursday. Be prepared by bringing the right equipment to travel over a variety of snow types and be sure you are able to stop yourself in case of a slip and fall. Choose safe travel routes that limit the distance you could slide and keep you away from terrain traps such as cliffs. In many areas of the zone, the snowpack has receded on southerly slopes near ridgelines or cliffs to expose early season hazards such as rocks, creeks, and stumps for you to be aware of.

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