[RW]

Avalanche Bulletin - Jasper National Park

Issued Thu Apr 24, 2014 17:37
Valid Until further notice
Wet loose avalanches can be expected at lower elevations if rain arrives in the valley bottom.

        

Danger Ratings: Friday

alpine treeline below treeline alpine: 3 - Considerable, treeline: 2 - Moderate, below treeline: 1 - Low
alpine: 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...
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: 1 - Low
1 - Low Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
  • 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.
More...
Forecast Saturday Sunday
alpine
3 - Considerable 2 - Moderate
treeline 2 - Moderate 2 - Moderate
below treeline 1 - Low 1 - Low
Confidence: Fair - Freezing levels are uncertain on Friday

Weather Observations

Past 24 Hr WeatherMarmot Basin 0800Columbia Icefields area
Maximum (°C)-3.64
Minimum (°C)-7.8-6
Snowfall (cm)00
Snow Pack (cm)13497
Wind speedLight (1-25 km/h)Light (1-25 km/h)
Ridgetop wind directionSESE
Past 24 Hr WeatherMarmot Basin 0800Columbia Icefields area
Maximum (°C)-3.64
Minimum (°C)-7.8-6
Snowfall (cm)00
Snow Pack (cm)13497
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: Storm Slabs

Which Elevation?

Which Elevation? alpine, treeline

Which Slopes?

Which Slopes? southeast, south, southwest, west, east

Chance of Avalanches?

Chance of Avalanches? possible

Expected Size?

Expected Size? small - large
With increased snowfall forecasted, this slab avalanche condition will likely build. Critical loading volumes may be reached in the alpine while at its lower elevation range, rain may act as a trigger.

Travel and Terrain Advice

  • The new snow will require several days to settle and stabilize.
  • Avoid convexities or areas with a thin or variable snowpack.

Problem 2: Loose Wet

Which Elevation?

Which Elevation? alpine

Which Slopes?

Which Slopes? south, southwest

Chance of Avalanches?

Chance of Avalanches? possible - likely

Expected Size?

Expected Size? small - small
On the 24th the new snow, found only at higher elevations on steep rocks, was being melted by brief moments of solar radiation. This condition will rapidly reestablish from the valley bottom to treeline with warm temperatures and rain.

Travel and Terrain Advice

  • Start and finish early before the surface crusts melt.
  • Make your travel plans to take advantage of overnight freezing.

Problem 3: 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? unlikely - possible

Expected Size?

Expected Size? small - large
This condition seems most active on, but not exclusive to, Easterly facing slopes. Shallow rocky spots in the snowpack are likely trigger areas.

Travel and Terrain Advice

  • Be aware of thin areas that may propogate to deeper instabilites.
  • Minimize overhead exposure during periods of heavy loading from new snow, wind.