Lawinenlagebericht

Mount Shasta

Mount Shasta Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Sun
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
Open full map
Veraltet — dieser Lagebericht ist 2 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Stormy weather means avalanche risk! On Mount Shasta, 10 inches of wet snow has fallen on variable, crusty surfaces since yesterday afternoon. Another healthy dump is expected today. Wind and storm slabs should be on your radar. Act with care, look for signs of unstable snow, and think thrice if committing to consequential avalanche terrain. 

Lawinenprobleme

  • Storm Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Mount Shasta has received upwards of a foot of new snow since yesterday, and another foot is possible today, if the forecast pans out. On the west side, new snow totals are much less. Storm slab danger can be a risk immediately during or just after a storm. Unstable storm slabs can be reactive for only an hour or two. Your best defense is to use small, steep slopes of non-consequence to test the snow. Small slopes are great indicators of how larger slopes may react. If you can easily trigger small storm slabs, then larger slabs are possible. Anywhere you observe significant new snow depths, keep storm slabs in mind.

    Example of storm slab

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    New snow and wind means wind slab potential, every time. Wind has blow primarily out of the SE, S and SW. This means that winds slabs could lurk on W, NW, N, NE and E aspects. Wind speeds increase with elevation. As you approach near and above treeline terrain, be vigilant for wind slab danger. The heavy, wet nature of the new snow may limit wind transport, but none-the-less... we must mention, and you must watch out. Avoid wind slabs by travelling in areas that are sheltered or wind-scoured. As always, observe for red flags: cracking, collapsing, blowing snow, recent avalanches, and hollow drum-like sounds in drifts.

    Visual depiction of wind loading and cross-loading dynamics

    Photo: Illustration from Allen & Mike’s Avalanche Book by Allen O’Bannon and Mike Clelland (Falcon Guides).

Avalanche Discussion

Since noon yesterday, Mount Shasta has received ~10 inches of wet snow (1.55" SWE) at 8,000 feet, accompanied by moderate wind blowing out of the SE, S and SW. In the Castle Lake and Eddy mountains, weather stations are reporting 2–3 inches. This was the result of the first, warmer wave of weather. Today will bring cooler temperatures, lower snow levels and a second wave of mountain snow.  Friday afternoon, the storm was just beginning to kick in. Visibility was difficult. About 2–3 inches of wet snow near treeline was observed on the mountain by close of business. The majority of the new snow fell into the evening, so some uncertainly remains on how the new snow will behave today. The warm to cold nature of the storms would suggest a "right side up" structure with good bonding to old snow surfaces. Notwithstanding, it will be important to watch for red flags of avalanche danger today. All said and done, we could have 1.5 to 2 feet of new snow on the mountain by the end of the weekend, with more wet weather expected next week. 

Abgedeckte Regionen