[DM]

Avalanche Bulletin - Glacier National Park

Issued Thu Nov 27, 2014 08:06
Valid Until Fri Nov 28, 2014 08:00
The Winter Permit System is now in effect. We are in the middle of a major storm. Avoid exposure to avalanche terrain.

        

Danger Ratings: Thursday

alpine treeline below treeline alpine: 4 - High, treeline: 4 - High, below treeline: 3 - Considerable
alpine: 4 - High
4 - High Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
  • Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
  • Natural avalanches likely; human-triggered avalanches very likely.
  • Large avalanches in many areas; or very large avalanches in specific areas.
More...
treeline: 4 - High
4 - High Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
  • Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
  • Natural avalanches likely; human-triggered avalanches very likely.
  • Large avalanches in many areas; or very large avalanches in specific areas.
More...
below treeline: 3 - Considerable
3 - Considerable Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
  • Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
  • Natural avalanches possible; human-triggered avalanches likely.
  • Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
More...
Forecast Friday Saturday
alpine
4 - High 3 - Considerable
treeline 4 - High 3 - Considerable
below treeline 3 - Considerable 3 - Considerable
Confidence: Good

Weather Observations

Past 24 Hr WeatherFidelity 1905mRogers Pass 1315m
Maximum (°C)-2-3
Minimum (°C)-8-4.5
Snowfall (cm)3634
Snow Pack (cm)14085
Wind speedCalm (0 km/h)Moderate (26-40 km/h)
Ridgetop wind directionNot AvailableS
Past 24 Hr WeatherFidelity 1905mRogers Pass 1315m
Maximum (°C)-2-3
Minimum (°C)-8-4.5
Snowfall (cm)3634
Snow Pack (cm)14085
Wind speedCalm (0 km/h)Moderate (26-40 km/h)
Ridgetop wind directionNot AvailableS
Low Moderate Considerable High Extreme
  • Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
  • Natural and human-triggered avalanches unlikely.
  • Small avalanches in isolated areas or extreme terrain.
  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
  • Natural avalanches unlikely; human-triggered avalanches possible.
  • Small avalanches in specific areas; or large avalanches in isolated areas.
  • Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
  • Natural avalanches possible; human-triggered avalanches likely.
  • Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
  • Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
  • Natural avalanches likely; human-triggered avalanches very likely.
  • Large avalanches in many areas; or very large avalanches in specific areas.
  • Avoid all avalanche terrain.
  • Natural and human-triggered avalanches certain.
  • Large to very large avalanches in many areas.

Problem 1: Storm Slabs

Which Elevation?

Which Elevation? alpine, treeline, below treeline

Which Slopes?

Which Slopes? north, northwest, west, southwest, south, southeast, east, northeast

Chance of Avalanches?

Chance of Avalanches? likely - very Likely

Expected Size?

Expected Size? large - very large
Touchy weak layers down ~80 and ~100cm are being rapidly loaded. These layers are easily triggered and are being overloaded resulting in natural avalanches. Avalanches have been running into valley bottoms overnight.

Travel and Terrain Advice

  • Use conservative route selection, choose moderate angled and supported terrain with low consequence.
  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Problem 2: Wind Slabs

Which Elevation?

Which Elevation? alpine

Which Slopes?

Which Slopes? northeast, north, east, southeast, northwest

Chance of Avalanches?

Chance of Avalanches? possible - likely

Expected Size?

Expected Size? small - large
Moderate southerly winds are loading lee slopes and forming more cohesive slabs. Wind loading will also trigger natural avalanches. Avoid exposure to steep paths that are being rapidly loaded, such as the Cheops North paths.

Travel and Terrain Advice

  • Avoid avalanche terrain during periods of heavy loading from new snow and wind.
  • Stay off recent wind loaded areas until the slope has had a chance to stabilize.

Problem 3: Loose Dry

Which Elevation?

Which Elevation? treeline, below treeline

Which Slopes?

Which Slopes? north, northwest, west, southwest, south, southeast, east, northeast

Chance of Avalanches?

Chance of Avalanches? likely

Expected Size?

Expected Size? small - large
Loose avalanches are possible on steep sheltered slopes and gullies. Be cautious in these areas, where a bit of sluffing snow can quickly gain mass.

Travel and Terrain Advice

  • Be aware of party members below you that may be exposed to your sluffs.
  • Watch for terrain traps where small amounts of snow will acumulate into deep deposits.