[GS]

Avalanche Bulletin - Banff, Yoho and Kootenay National Parks

Issued Thu Apr 24, 2014 17:00
Valid Until Fri Apr 25, 2014 17:00
Clear skies and cold temperatures produced a solid freeze last night. The same is expected for Friday if the skies clear tonight. Excellent conditions: soft powder on shaded slopes and frozen/corn snow in the sunshine below 2200m in the afternoon.

        

Danger Ratings: Friday

alpine treeline below treeline alpine: 2 - Moderate, treeline: 1 - Low, below treeline: 1 - Low
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: 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...
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
2 - Moderate 2 - Moderate
treeline 1 - Low 1 - Low
below treeline 1 - Low 1 - Low

Weather Observations

Past 24 Hr WeatherN Kootenay 1985/2405mBow Summit 2000mSunshine 2200m
Maximum (°C)35Not Available
Minimum (°C)-7-10Not Available
Snowfall (cm)31Not Available
Snow Pack (cm)239182Not Available
Wind speedLight (1-25 km/h)Light (1-25 km/h)Not Available
Ridgetop wind directionSWSWNot Available
Past 24 Hr WeatherN Kootenay 1985/2405mBow Summit 2000mSunshine 2200m
Maximum (°C)35Not Available
Minimum (°C)-7-10Not Available
Snowfall (cm)31Not Available
Snow Pack (cm)239182Not Available
Wind speedLight (1-25 km/h)Light (1-25 km/h)Not Available
Ridgetop wind directionSWSWNot Available
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: Wind Slabs

Which Elevation?

Which Elevation? alpine

Which Slopes?

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

Chance of Avalanches?

Chance of Avalanches? possible

Expected Size?

Expected Size? small - large
Reported in the high alpine (peaks on the Wapta), these small slabs have resulted from the new snow that fell over the past 48 hours.

Travel and Terrain Advice

  • Use caution in lee areas. Recent wind loading have created wind slabs.

Problem 2: Deep Persistent Slabs

Which Elevation?

Which Elevation? alpine

Which Slopes?

Which Slopes? east, northeast, north, northwest

Chance of Avalanches?

Chance of Avalanches? unlikely - possible

Expected Size?

Expected Size? small - large
The deep, persistent weakness remains in the snowpack. This problem appears dormant until the next big warm spell, but we continue to note it's presence.

Travel and Terrain Advice

  • Be aware of the potential for full depth avalanches due to deeply buried weak layers.