Lawine

Highway 2/ Elk Mountain

blase reardonFlathead Range & Glacier NP
Auf der Karte ansehen
Beobachtungsfoto 1

Quick report

Spent the morning avalanche gawking and cataloging, then skinned part way up Elk Mountain to get a feel for the snow. 

  • Multiple D2, D2.5 and D3 crowns from natural slab avalanches 3/15 and today. These were mostly on upper elevation, sunny slopes, which was also the most visible terrain. The crowns often linked across terrain features. Some looked to have been triggered by rollerballs, loose wet snow slides, or cornice falls. 
  • Noted some large (D2-2.5) wet snow avalanches, again on sunny/ windward slopes. 
  • Our ascent/ descent route to 7200 feet was free of overhead hazard and never exceeded 31 degrees. Anything else would have exposed us to today's multiple avalanche problems. 
  • Overnight inversions and mostly clear skies left a thin but supportable crust on the slopes where we traveled this afternoon. This would have made for excellent corn skiing, had we spent less time gawking and started earlier.

Camera glitches meant few decent photos. argh.

Weather

Air Temp
45
Cloud Cover
few
Wind Loading
none
Snow Avail For Transport
none

Morning inversion gave way to very warm mid afternoon temps with nearly calm winds and scattered high, thin clouds.

Snowpack

Supportable melt-freeze grains (5-10 cm thick) to about 5700 feet, and on wind hardened surfaces higher. This surface was still frozen in the shade in early afternoon. By mid afternoon, it had softened enough that we released some roller balls on our turns. Skis and board sunk sporadically. 

Quick pit at our high point (~7200 ft) on  a cross-loaded, west facing ridge. HS 180 cm. 

  • Top 10 cm wet. 
  • Double melt freeze crust down about 30 cm. P hard.
  • 50-55 cm 1 F  to 1 F+ hard dry snow
  • 1 cm thick ice layer (2/3) down ~65-70 cm. Degrading. Not knife hard in this location/ at this time. 
  • Probing below crust showed some softer layers below crust, but did not dig below ice. 

Many windward and sunny slopes looked to have unusually thin snow cover - less than a meter.

Avalanche

Size
D2 R2
Type
HS
Count
10
Aspect
SW
Trigger
NL
Elevation
7100 ft

Not visible in AM, or by another observer late 3/15. Several crowns with rollerballs/ loose debris above from trees. Ran to "landing strip" in middle of path.