Avalanche Forecast
Issued: Feb 12th, 2020 2:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
jfloyer,
Avalanche Canada
Ongoing stormy weather will maintain elevated avalanche danger through the second half of this week. Pay attention to new snow amounts and avoid wind-affected slopes. Areas that receive 25 cm or more new snow in a 24 hour period should consider the avalanche danger to be HIGH.
Summary
Confidence
Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.
Weather Forecast
Wednesday night: 10-15 cm new snow focussed on the west of the region. Strong southwesterly winds.
Thursday: 10-15 cm new snow. Strong southwesterly winds. Freezing level around 800 m.
Friday: 10 cm early morning with snow easing by mid-morning. Moderate westerly winds. Freezing level lowering to surface with treeline temperatures around -6C.Â
Saturday: 10 cm new snow. Moderate southwesterly winds. Treeline temperatures around -3C.
Avalanche Summary
A few loose snow avalanches were reported from the Torpy on Monday.
With new snow and wind in the forecast, I anticipate natural and human-triggered avalanches will increase in likelihood toward the end of this week.
Snowpack Summary
A layer of surface hoar appears to have become buried by light snow. We don't know too much about the distribution of this layer and it may have been impacted by strong winds in some areas. It is buried approximately 40 cm in the south of the region and 10-20 in areas further north and east. Initially the bond at this interface was reported to be reactive. However, cold overnight temperatures appear to have improved the strength at this interface.
Slightly lower in the snowpack, approximately 40-60 cm below the surface, there is a thin rain crust from the warm, wet storm on Feb 01. This rain crust has been reported to exist up to treeline elevations around 1700 m. Initially this layer was described as reactive and was the focus of a number of avalanches. However, it now appears to be gaining strength and probably won't end up being a significant long-term weak layer.
In the mid-pack there may still be a layer of surface hoar buried in late December. It's gaining strength, but should remain a concern since snowpack tests still demonstrate this layer has the potential to slide, albeit in isolated areas and/or with very large triggers.
Terrain and Travel
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Cornice failure may trigger large avalanches.
Problems
Storm Slabs
Expect avalanches to become easily triggered as storm snow amounts increase, particularly in wind-affected areas.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices have been reported to be especially large. Cornice collapses become likely in warmer temperatures and/or when the sun is out. The weight of a large cornice dropping could be sufficient to trigger a large avalanche on the slope below.
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 14th, 2020 5:00PM
