Lawinenlagebericht

Mount Shasta

Mount Shasta Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Wed
Hochgebirge
2 · Mässig
Waldgrenze
1 · Gering
Unterhalb
1 · Gering
Open full map
Veraltet — dieser Lagebericht ist 8 months ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Today, small avalanches will be possible in leeward and cross loaded terrain above tree line on Mount Shasta. Inclement weather, strong winds and firm snow surfaces will preclude favorable recreating opportunities in the alpine. However, the avalanche problem can best be managed by sticking to wind scoured terrain and avoiding wind loaded features of concern. 

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–1.5

    New snow in conjunction with moderate west winds will create the potential for cohesive slabs of drifted snow in lee and cross loaded terrain, primarily above treeline on Mount Shasta. Any avalanches will be small and located where there is a preexisting bed surface. Precipitation amounts today will be less than a quarter inch with the bulk, around half an inch, falling after 4 pm through tomorrow morning. While technically during the forecast period, the overnight snow will be more of a concern for tomorrow. Winds also increase in speed overnight and shift more southwest.

    Slabs are most likely on the highlighted aspects, but may form on any due to the strong local orographics of Shasta and irregular loading patterns during strong to extreme winds. This makes it especially important to recognize wind slabs and where they form – Rounded features of locally deeper snow, most typically downwind of ridgelines and other terrain features.  Above treeline, the best way to manage the problem is by avoiding the features of concern and sticking to wind scoured areas or lower angle slopes. Signs to watch out for include blowing snow and cracking/collapsing on small test slopes. In our shallow snowpack, the consequences of being caught in even a small slide are high due to the slick bed surfaces and exposed or shallowly buried rocks. 

Avalanche Discussion

Active weather returns to the forecast zone following nearly a month-long drought. Precipitation began last night and will continue today in small amounts. Snow levels remain well above tree line before lowering around 6,000 feet Wednesday morning. With the arrival of the new snow, it is important to take note of the preexisting distribution, the bulk of which is confined predominantly above tree line on Mount Shasta. Starting zones and ridgeline features that hold continuous or near continuous coverage are the area’s most likely to produce avalanches from wind drifted snow. 

On top of this general pattern, snow is found to lower elevations on shadier aspects and higher on the most solar. Below tree line, a patchwork of snow exists in sheltered sites above roughly 7,000 feet. The east side of the mountain holds a lower snow line, but still requires patchy travel for a thousand vertical feet or so. In the west side of the zone, coverage is limited to all but the highest north-facing terrain. Old snow surfaces are best summarized as firm and variable, including significant wind texture and thick melt-freeze crusts. Exposed and shallowly buried obstacles are abundant in the pack.

Visit our observation page for recent conditions updates in the forecast zone and please consider submitting one yourself! We appreciate them all! This Friday, December 19th, the Avalanche Center will be hosting its annual movie night, which will be a double feature! See our events page for a description of both films and more venue details. Doors open at 5:30 pm at Mountain Medics and the films start at 7:00 pm. Bring your stoke as winter weather returns!

Abgedeckte Regionen