Lawinenlagebericht

Flathead Range & Glacier NP

Flathead Avalanche Center
Auf der Karte ansehen

Lawinengefahr

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

Kernpunkte

Atypical winds will continue to drift new snow in unusual places. Steer around fresh slabs to safely enjoy some much-needed powder. There remains a chance you could trigger an avalanche on a deeply buried weak layer on drier, northerly upper-elevation slopes.

 

Lawinenprobleme

  • Wind Slabs

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

    Recent snow has been and will continue to be drifted by north and east winds throughout the day. There is little snow to work with in most locations, so slabs should generally be thin, small, and easy to avoid. These features are forming on top of a stout crust, which may add to their instability. 

    Atypical winds are notorious for affecting the snow surface in unusual locations. Dense snow, scalloped surfaces, and dunes are signs the wind has been at work. Cracking in the surface snow indicates instability, directing you to seek out sheltered terrain or a lower-angle slope.

    Blowing snow like this indicates that the wind is drifting snow and possibly forming wind slabs beneath the ridge line. 

    Photo: Rob Millspaugh

  • Persistent Slabs

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

    A buried faceted crust remains a concern on slopes where this layer remained dry during last week's abnormally warm temperatures. These locations should be limited to the highest slopes facing northwest to north to east. Although unlikely, a rider could still trigger a large destructive avalanche several feet deep in locations where the faceted layer is intact and weak. 

    Choose terrain wisely by steering clear of locations where you are most likely to trigger a slide. These include convexities, scoured slopes with a thin snow cover, and rock outcroppings. The snowpack may or may not give you signs, such as collapsing, before an avalanche occurs.

     

    (2/1/2024)

    A snowpit on a north aspect revealed a 155 cm depth at 6650'. The entire pack was moist and capped by a thin, breakable crust. The blue arrow denotes what we believe to be the deteriorating 12/22 crust.

    Photo: Mark Dundas

Avalanche Discussion

Snow is back in the forecast, and a welcomed cooling trend is expected today with northeast winds. As of 5 AM, snow accumulations are meager, with most mountain weather stations reporting several inches. However, snowfall totals will likely increase as you gain elevation, as blase and I observed yesterday while skiing 4 inches of new snow on the west side of the Continental Divide in the Skyland area. 

Cooler temperatures today will strengthen the recently warm, wet snowpack into a supportable crust, likely ending our concerns with wet snow instabilities. Yesterday (Saturday), observers (observation 1 and observation 2) around Whitefish Mountain Resort reported better-than-expected skiing in 1-2 inches of new snow above a supportable crust. 

Northeast winds are the wild card of our forecast. They often wreak havoc on the front side of WMR and the Swan front, while mostly unaffecting the narrow drainages of the Middle Fork. However, today’s winds are generally mild and short-lived compared to many of our recent Arctic intrusions. Today, locations that do not experience wind effects will remain at LOW danger. 

From January 28th through the 30th, numerous large avalanches ran naturally. Some slid on old, weak layers or stepped down to the ground. We are still looking for old crowns and avalanche debris to understand the full extent of this warm, wet storm. Check out our observation page for a catalog of reported avalanches.

Upcoming event: Flathead Avalanche Friends Fest, February 21-24. Beacons & Brews, Name That Tune/Name That Avalanche, Workshop Night, Hot Dog Days, and Ultimate Après.  Check out 4 days of events: flatheadavalanche.org/event/friendsfest

Abgedeckte Regionen