Avalanche Forecast
Issued: Jan 19th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
mconlan,
Avalanche Canada
New slabs may be touchy and the warming trend has the potential of waking up the buried weak layer. Travel conservatively during this period of uncertainty.
Summary
Confidence
Moderate - Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.
Weather Forecast
SUNDAY NIGHT: Cloudy with snowfall, accumulation 3 to 10 cm, moderate to strong southwest wind, alpine temperature -2 C, freezing level rising to 1000 m.
MONDAY: Cloudy with snowfall, accumulation 5 to 10 cm, moderate to strong southwest wind, alpine temperature -3 C, freezing level 1200 m.
TUESDAY: Cloudy with snowfall, accumulation 2 to 5 cm, light to moderate south wind, alpine temperature -5 C, freezing level below valley bottom.
WEDNESDAY: Morning snowfall then a mix of sun and cloud, accumulation 1 to 3 cm, light southwest wind, alpine temperature -7 C, freezing level below valley bottom.
Avalanche Summary
Avalanche activity has quieted down over the past few days, but new snowfall, strong southwest wind, and a rise in air temperature will likely produce new slabs, with the most reactive being in exposed terrain at and above treeline.
There hasn't been an avalanche reported on the persistent slab problem since January 13. The likelihood of triggering this layer could increase as the air temperature rises on Sunday night into Monday.
Snowpack Summary
The south of the region received around 10 to 20 cm of snow on Saturday and another 10 to 20 cm of snow may accumulated Sunday night into Monday. The snow is accompanied by strong southwest wind as well as an increase in the freezing level, meaning that the snow may form cohesive slabs relatively quickly. The touchiest slabs will likely be in lee terrain features at and above treeline.
The main concern over the past couple of weeks has been a layer of surface hoar buried 60 to 120 cm deep. Although an avalanche has not been reported on this layer in the past six days, the likelihood of triggering it may increase as the air temperature warms.
Terrain and Travel
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Extra caution for areas experiencing rapidly warming temperatures for the first time.
- Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
Problems
Storm Slabs
Around 10 to 30 cm of recent snow will have accumulated in the region by Monday afternoon, with associated strong southwest wind and relatively warm air temperature. This weather recipe will form new slabs, with the touchiest likely being at and above treeline in lee terrain features near ridges.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A layer of surface hoar is buried 60 to 120 cm deep. As the air temperature rises on Monday, the likelihood of triggering this layer may increase. Use added caution in clearings around treeline during periods of warming.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Jan 20th, 2020 5:00PM
