Lawinenlagebericht

Flathead Range & Glacier NP

Flathead Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Tue
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Open full map
Veraltet — dieser Lagebericht ist 5 months ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

A strong refreeze at the snow surface will start the day off at LOW avalanche danger. Warming temperatures and solar radiation will increase the avalanche danger throughout the day. Move to lower-angle slopes once the start zones above you have received more than a few hours of direct sun. Lower angled slopes shaded by the sun will also provide a safer alternative.

Lawinenprobleme

  • Wet Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    Natural and human-triggered avalanches are unlikely when a hard and supportable surface crust exists. However, the likelihood of an avalanche failing deep in the snowpack will increase once the surface crust breaks down. That window of time will depend on the extent of sun and cloud cover, and on freezing levels. We anticipate that clear skies will keep the surface frozen on NW-, E-, and SE-facing slopes, where the Persistent Slab structure is most widespread and best developed. Nonetheless, if you don’t find a surface crust on those aspects, move to lower-angle terrain.

    Warming temperatures and solar radiation will increase the flow of liquid water into the snowpack, thus increasing the threat of avalanches later in the day. Be wary of traveling on or below any steep slope once the surface crust breaks down. The recent warming/rain event produced very large (D3+) avalanches. Some broke 1900 feet wide and up to 8 feet deep. These avalanches are no joke. Put ample space between yourself and steep terrain during the heat of the day.

    (3/22/2026)

    Crown from a second slab avalanche that was likely triggered by debris from a very large (D3) avalanche on the north face of Sixmile Mountain in the Swan Range. 

    Photo: Flathead Avalanche Center

Avalanche Discussion

A short-lived spring diurnal cycle is underway. Overnight refreezes are providing a window of stable avalanche conditions in the morning hours. If you time everything just right, you may get some decent riding before the sun and warm temperatures get to work on the upper snowpack. The most important suggestion I can give is to stay one step ahead of changing conditions.

Meltwater moving through the snowpack is the driving force behind avalanche danger and problems. Today, solar radiation will drive water movement through the snowpack. The late March sun is now touching northwest facing slopes. Once the crust breaks down and the flow of water returns, the chances of it weakening the January Drought Layer increases. Since liquid water has reached, or may soon reach the January Drought Layer, we transitioned the avalanche problem to a Wet Slab problem. 

There is a chance you may run into some small avalanche problems throughout the day. We may see some small wet loose avalanches on sun-cooked slopes, and there may be a few lingering wind slabs at the uppermost ridgelines. These should be generally harmless as long as you don't get knocked over in consequential terrain.

 

Abgedeckte Regionen