Wind Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible - Likely
- Size
- 1–2
Lingering wind slabs in the alpine may be sensitive to human triggers. Watch for triggering in the lee of ridge crests and in gullies.
Avalanche forecast
View on mapSouth Rockies
Apr 6 – 7, 2015Avalanche Canada
Archived · expired 11 years ago
Avalanche danger
Wed
Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Highlights
Snowpack and avalanche observations are becoming scarce. If you've been in the backcountry, please tell us what you've seen here on the Mountain Information Network.
Avalanche problems
Cornices
NNEESESSWWNW- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–4
Large cornices at ridgetop may fail under the weight of a human-trigger. As spring conditions evolve, remember that destructive cornice falls become more likely during periods of warming and solar radiation.
Loose Wet
NNEESESSWWNW- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
Sluffing can be expected from steep sun-exposed slopes during the heat of the afternoon.
Confidence
Fair - Timing or intensity of solar radiation is uncertain
Weather Forecast
A ridge of high pressure moves over the interior on Tuesday and should be the dominant feature for the rest of the week. On Tuesday, a mix of sun and cloud is expected with light alpine winds and freezing levels reaching around 2000m in the afternoon. Isolated convective flurries are possible. Mostly sunny conditions with light alpine winds are expected for Wednesday and Thursday. Freezing levels are forecast to reach around 2000m on Wednesday and 2300m on Thursday.
Avalanche Summary
Observations are becoming very limited as we enter spring. If you're out in the mountains, please consider posting your observations to our webpage. In the Lizard range on Saturday and Sunday, loose sluffing was reported from steep features. Also in the Lizard on Saturday, ski cutting produced small soft slab avalanches in wind loaded features. With freezing levels rising and lots of sun expected on Tuesday, lots of natural sluffing is expected from steep sun-exposed slopes. Cornices will become weaker than they have been for the last week and may fail naturally. Wind slabs in the alpine are expected to be sensitive to human-triggering. Reverse loading may have occurred and wind slabs should be expected in leeward features on all aspects.
Snowpack Summary
10-20cm of recent snow overlies a widespread and supportive melt-freeze crust. Recent strong winds may have redistributed the surface snow resulting in wind slab formation in the alpine and exposed areas at treeline. Large cornices exist in the alpine and may become weak with daytime warming. The mid-March rain crust is down 35 to 70cm and has shown a good bond with snow above. Old persistent weak layers are still intact in the mid and lower snowpack and there may be potential for these layers to wake up with a big cornice fall, sustained warming and/or a significant rain event.