Avalanche Forecast
Regions: North Columbia.
Fresh storm slabs at upper elevations will likely be reactive to human triggers; especially in lee features below ridgetops.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
FRIDAY NIGHT: Clearing / Light, northwesterly winds / Alpine low -4 C / Freezing level 1400 m.
SATURDAY: Sunny / Light, northwesterly winds / Alpine high -2 C / Freezing level 2000 m.
SUNDAY: Sunny / Light, southwesterly winds / Alpine high -1 C / Freezing level 2200 m.
MONDAY: Sunny / Light to moderate, southwesterly winds / Alpine high 0 C / Freezing level 2200 m.
Avalanche Summary
No new avalanches were reported on Thursday.
On Tuesday, a natural size 2.5 persistent slab avalanche was reported on a west aspect at 2750 m. Additionally, a skier triggered size 2 storm slab avalanche was reported on an east aspect at 2700 m.
On Monday, a skier remotely triggered a size 2 storm slab from 10 m. away on a steep north facing feature in the alpine that was 20-30 cm. deep.
Snowpack Summary
30-40 mm of rain has soaked the snowpack at treeline and below. The rain/snow boundary on Friday was around 2100 m. New snow amounts in the alpine will taper rapidly with elevation and likely equate to around 15-25 cm of moist snow at upper elevations adding to the 20-40 cm recent snow which overlies a crust everywhere except high elevation, north facing terrain where preserved surface hoar (weak, feathery crystals) may be present in isolated locations down 30-60 cm. A similar layer buried in early April is down 50-80 cm. Smaller storm slab avalanches may step down to one of these deeper weak layers.
Below treeline, snow is disappearing rapidly.
Avalanche Problems
Storm Slabs
Fresh storm slabs at upper elevations will likely be reactive to human triggers; especially in lee features below ridgetops.
- Use small slopes without consequence to test the bond of the recent snow.
- Pay attention to changing conditions with elevation/aspect.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Likely
Expected Size: 1 - 2.5
Loose Wet
If temperatures remain warm and the solar radiation is strong, loose wet avalanches are still possible at treeline and likely in the alpine where there is new snow.
- A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.
- Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.
Aspects: East, South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2