Avalanche Forecast North Columbia

Date Issued: Valid Until:

Avalanche Canada jsmith, Avalanche Canada

Avalanche Forecast

Tue Apr. 23rd ยท 3:57PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Wind Slabs Wind Slabs
Loose Wet Loose Wet

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Lingering wind slabs may still be reactive to human triggers; especially on lee features below alpine ridgetops.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TUESDAY NIGHT: Mostly cloudy with isolated alpine flurries; 1-3 cm / Light, northwesterly winds / Alpine low -4 C / Freezing level 1300 m.

WEDNESDAY: Mix of sun and cloud / Moderate, northwesterly winds / Alpine high 0 C / Freezing level 1500 m.

THURSDAY: Sunny / Light, westerly winds / Alpine high 3 C / Freezing level 2000 m.

FRIDAY: Cloudy with isolated alpine flurries; 0-3 cm / Light, southeasterly winds / Alpine high 1 C / Freezing level 1800 m.

Avalanche Summary

No new avalanches were reported in this region on Monday. However, there are currently very few professional observers submitting daily observations. Please submit your observations to the MIN. Photos of avalanches or current conditions are particularly useful.

On Saturday, numerous, natural loose wet avalanches up to size 1.5 were reported on steep solar aspects at treeline and above in the afternoon.

A widespread storm slab avalanche cycle to size 3.5 on all aspects in the alpine was reported on Friday. Although not in this region, check out these two MIN reports from Saturday in Glacier National Park HERE. and HERE.

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.

Problems

Wind Slabs

Wind Slabs

Lingering wind slabs may still be reactive to human triggers; especially on lee features below alpine 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: North, North East, East, South East, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2
Loose Wet

Loose Wet

Strong solar radiation may trigger loose wet avalanches on steep terrain; especially at upper elevations 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: North East, East, South East, South, South West, West, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2