Bulletin d’avalanche

Olympics

Northwest Avalanche Center
Voir sur la carte

Danger d’avalanche

Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
Open full map
Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

You could trigger slabs within drifts up to 1.5 ft or loose avalanches within 10" of storm snow. Steer around steep, unsupported open slopes where these problems come into play. If trees and rocks start shedding snow, navigate to cooler, shaded aspects.

Problèmes avalancheux

  • Wind Slabs

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

    Storm snow was right side up and well-bonded to the 2/20 crust, but has been redistributed anywhere from 2-16" deep. Probe the snow depth above the crust as you travel and you're likely to find the deeper drifts preferentially on easterly aspects near and above treeline. These wind-loaded pillows will be most prone to slab formation with the most significant wind loaded expected just below ridgelines. If you suspect loading on a slope, steer around slopes 35 degrees and steeper, particularly where the slope rolls away.

    Dry loose avalanches may run far and fast in any terrain approaching 40 degrees and steeper. This can be consequential where it could push you over a cliff or into unwanted obstacles.

    (2/23/2023)

    Cracking on wind pillows at ridgeline

    Photo: Sam Siemens-Luthy

Avalanche Discussion

Avalanche Fatality: Colchuck Pk, East Central Zone: Read the preliminary report here.

Although Friday starts very cold, sunny skies, gradually moderating temperatures and light winds will combine to allow SW-S-SE aspects to warm and destabilize by the afternoon.  If you see snow shedding off trees and rocks or rollerballs forming, reduce your exposure to steep slopes receiving sunshine on the slopes above you and navigate to cooler shaded slopes.

Observers reported fantastic riding conditions on Thursday. 2-3" of fresh snow had fallen since 2/22 with very low density "snow flurries" continuing to pile up.  8-10" of snow now sits over the 2/20 crust.  Although winds have been shifting direction, more snow loading appears to have occurred on E aspects.

Snow pits at 5000 ft on an E aspect show two crust sandwiches (see media gallery). The upper one was formed warmer daytime temperatures 2/20 and 2/19 with some snowfall in between. Snowpack tests show a slight weakness just below the 2/20 crust proper, but it does not appear concerning. The lower double crust formed around 2/13. The layer of snow between the two crusts has consolidated significantly since last week.

Régions couvertes