Bulletin d’avalanche

West Slopes Central

Northwest Avalanche Center
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Danger d’avalanche

Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré last year. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Friday will bring spring-like conditions with lots of sunshine and warmer temperatures. As the day heats up, monitor steep slopes above you. Avoid traveling on or immediately beneath any steep slopes showing fresh rollerball or wet avalanche activity, or where the snow is soft and saturated.

Problèmes avalancheux

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    With prolonged warming also comes the increased chance of seeing cornice falls, snow shedding from cliffs, and gullies emptying snow, especially during the heat of the day. It might not be spring, but it will be a day to tap into the spring mindset. Big alpine terrain produced some big wet avalanches in the Central Cascades on Thursday. Reduce your exposure as temperatures rise.

    Wet avalanche activity could vary widely across the forecast zone tomorrow. In some areas, they have already peaked, while others have yet to see a significant cycle. Many - but not all - lower elevation slopes now lack the snow cover to produce real avalanches. 

    Cloud cover overnight Thursday could affect the level of avalanche activity on Friday. If it’s clear and cooler, expect a crust in the morning and avalanches mostly limited to slopes seeing the sun. If it is cloudier and warmer overnight, you are more likely to see them on all aspects. 

    (2/27/2025)

    Loose wet avalanches often initiate in steep, rocky terrain. Blanca Lake area.

    Photo: Irene Henninger

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1–1.5

    Strong winds hammered some upper-elevation locations on Thursday. Dense or crusty snow at the surface probably reduced the amount of snow available for transport, but there are some slabs somewhere out there. Most should be small but can still do harm if you take a ride on one in consequential terrain.

    Use visual clues like scoured snow surfaces and cornices to figure out where stiff slabs may have formed. Hand shears and test slopes can help you gauge wind slab reactivity. Recently formed slabs sometimes increase in reactivity when they see some warming.

    Small wind loaded features at ridgeline can serve as test slopes to gauge the reactivity of fresh wind slabs.

Avalanche Discussion

An NWAC Forecaster north of Hwy 2 in West Central found evidence of a widespread natural avalanche cycle that likely occurred during the latest storm on Tuesday.  The new snow has since settled and was observed as well-bonded and unreactive in testing. Other than large avalanches in alpine terrain, the most notable observation was an increasing amount of wet avalanche activity throughout the day. Wet snow and human-triggered rollerballs were even occurring on more northerly aspects. No wind slabs were found, but moderate wind transport and fresh but shallow wind slab formation were noted in neighboring forecast zones.

Previous weak interfaces buried in late January and mid-February have seen extensive loading - 10” or more of precipitation! - and are now considered old news. Widespread avalanche debris from the rain event and the natural avalanche cycle on February 22nd is still evident. 

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