Avalanche Forecast
Issued: Apr 7th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Cornices.
Stephen Holeczi,
There is a huge range of conditions over the forecast region. Also, some unexpected deeper releases two days ago have lowered our confidence. Winds should decrease tomorrow, but watch for fresh wind slabs in the alpine.
Summary
Weather Forecast
5-10cm are expected along the divide tonight with less out East. Strong SW winds will diminish Wednesday night and will be moderate for Thursday. Temperatures will dip below freezing tonight at valley bottom, and 3000m temperatures will drop to -15C.
Snowpack Summary
The snow surface is mix of crusts to 1800 m, and dry powder snow on north facing slopes above 1800 m. New snow, strong winds and cooling temps have promoted some wind slab development. Treeline and below treeline elevations should become frozen and stay mostly frozen. Quite a variable spring snowpack.
Avalanche Summary
No new avalanches reported today. There were a few deeper releases yesterday on Mt. Des Poilus and in the Lake Louise backcountry up to size 3.5. It is unsure the sliding surface, but they started as smaller slabs that had enough weight to dig down deeper. Also yesterday an almost full burial near Lake Agnes in the alpine with no injuries.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
Problems
Wind Slabs
Strong alpine winds and forecast snow Wednesday night have potential to make new wind slabs at higher elevations. This conditions is expected mostly along the divide and West where the forecasts are showing the most snow.
- Be careful with wind loaded pockets, especially in steep confined alpine terrain.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Numerous deeper releases were noted over the past 2 days (see avalanche table). There is lots of uncertainty as to which layers within the snowpack these slid on. We will be monitoring this in the coming days to see if it continues.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Cornices
Cornices are big and the springtime is when they fall off more frequently. We have had fairly regular observations of cornice failures over the past few weeks, so minimize your exposure to them especially as the day heats up or the winds increase.
- Cornices become weak with daytime heating, so travel early on exposed slopes.
Aspects: North, North East, East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 8th, 2021 4:00PM
