Boletín de aludes

Stevens Pass

Mar 8 – 9, 2020Northwest Avalanche Center
Ver en el mapa
Archivado · caducó 7 years ago

Peligro de aludes

Tue
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
Abrir el mapa completo

Lo esencial

Expect strong solar radiation on Monday to create small wet loose avalanches on steep sun-exposed slopes. If you notice snow surfaces becoming wet and weak, move to shaded or lower angled terrain. 

Problemas de aludes

  • Loose Wet

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1

    Monday will bring the first full day of strong sunshine following several days of light, intermittent snowfall and mostly cloudy skies. Temperatures should remain cool, but snow surfaces will rapidly lose strength on sunny slopes, and natural wet loose avalanche activity is expected. The sun will move around the compass heating up different aspects throughout the day. East facing slopes will begin first mid-morning, then souths soon after, and westerlies by afternoon. Time your travel carefully, and keep return routes in mind - cold slopes you crossed safely early in the day could be wet and weak by afternoon after baking in the sun. Be especially careful around steep sun-exposed rocky slopes and cliff bands. Watch for rollerballs and pinwheels, and stick to shaded or lower angle terrain to avoid the problem. Large cornices also loom on most high ridges. Use caution to not travel on or underneath overhung cornices.

Snowpack Discussion

March 5, 2020 (The regional synopsis is updated every Thursday @ 6 pm)

Ridgetop wind transport near Washington Pass. 3/4/20 Photo: Josh Hirshberg

 

The beginning of March brought the first spring-like weather to the region. The days are getting longer and the sun (when it shines) has a noticeable effect on the snow. Alternating sun breaks and snowstorms is the theme of the week and the avalanche danger fluctuated just as fast as the weather. The southern zones and the east slopes have seen periods of light snowfall and significant sunshine while the northern zones and west slopes have had significant snowfall and occasional sun breaks. Above freezing temperatures were common at lower elevations throughout the region. 

Last week in review:  Temperatures were above freezing at most trailhead locations and concerns about the previous week’s buried surface hoar and weak layers were fading. Saturday temperatures plummeted as strong winds and new snow built wind slabs in most areas and drove the avalanche danger to considerable in almost every zone. Sunday’s calm weather and clearing in most areas helped stabilize wind slabs, but our attention turned to the strength of the sun and daytime warming. Lingering wind slabs and loose wet avalanches were forecast in every zone. For the remainder of the week, the avalanche problems in every zone were confined to the recent snow and each brief storm cycle had us thinking about wind slabs at upper elevations and loose wet avalanches from daytime warming and sunshine.

Spring isn’t actually here -- another round of cold temps and snow showers are on the way this weekend, but this past week’s oscillating weather is a good reminder to begin to shift our mindset. The sun is gaining strength, the days are getting longer, and we begin daylight savings this week. Even a brief period of sunshine can dramatically alter fresh, new snow. Check the mountain weather and avalanche forecasts for the most up to date info, enjoy the backcountry and let us know what you see out there!

--Peter Moore

Wet loose avalanche debris near Snow Lake. 3/5/20 Photo: Dallas Glass

Fresh cornice development from strong winds in the Stevens Pass backcountry. 3/4/20 Photo: Tom Whipple

Regiones cubiertas