[RW]

Avalanche Bulletin - Jasper National Park

Issued Thu Apr 17, 2014 17:24
Valid Until Fri Apr 18, 2014 17:00
Rain events will increase the avalanche danger. On Saturday avalanche control and road closures between Parker Ridge and the Weeping Wall will occur from 4:00-8:00 PM. The Maligne Lake road may also be closed on Saturday.

        

Danger Ratings: Friday

alpine treeline below treeline alpine: 2 - Moderate, treeline: 2 - Moderate, below treeline: 2 - Moderate
alpine: 2 - Moderate
2 - Moderate Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
  • 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.
More...
treeline: 2 - Moderate
2 - Moderate Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
  • 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.
More...
below treeline: 2 - Moderate
2 - Moderate Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
  • 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.
More...
Forecast Saturday Sunday
alpine
2 - Moderate 2 - Moderate
treeline 3 - Considerable 1 - Low
below treeline 3 - Considerable 1 - Low
Confidence: Fair - Intensity of incoming weather systems is uncertain

Weather Observations

Past 24 Hr WeatherMarmot Basin 0800Columbia Icefields area
Maximum (°C)-48
Minimum (°C)-10.6-5
Snowfall (cm)33
Snow Pack (cm)142101
Wind speedLight (1-25 km/h)Light (1-25 km/h)
Ridgetop wind directionSESE
Past 24 Hr WeatherMarmot Basin 0800Columbia Icefields area
Maximum (°C)-48
Minimum (°C)-10.6-5
Snowfall (cm)33
Snow Pack (cm)142101
Wind speedLight (1-25 km/h)Light (1-25 km/h)
Ridgetop wind directionSESE
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: Loose Wet

Which Elevation?

Which Elevation? below treeline, treeline

Which Slopes?

Which Slopes? southeast, south, southwest, west

Chance of Avalanches?

Chance of Avalanches? possible - likely

Expected Size?

Expected Size? small - large
The snowpack is warming up and the restraining crusts are weakening with the warm weather. Point releases from steep rocks at all elevations are a concern as they can trigger both dry and wet snow avalanches. Rain will increase the activity.

Travel and Terrain Advice

  • Be very cautious with gully features.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Problem 2: Deep Persistent Slabs

Which Elevation?

Which Elevation? alpine, treeline

Which Slopes?

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

Chance of Avalanches?

Chance of Avalanches? possible

Expected Size?

Expected Size? small - large
These events will be of greatest concern with warm temperatures and rain. They may be triggered by smaller surface avalanches such as point releases from steep rocks or cornice failures.

Travel and Terrain Advice

  • Be aware of thin areas that may propogate to deeper instabilites.
  • Avoid convexities or areas with a thin or variable snowpack.