Avalanche Forecast
Issued: Jan 5th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Wet.
mconlan,
Avalanche Canada
The recent snow may become more reactive as the next storm approaches on Monday, bringing warm air and a switch from snow to rain. Expect rapidly changing snowpack conditions as the weather changes.
Summary
Confidence
Weather Forecast
SUNDAY NIGHT: Mostly cloudy with isolated flurries, accumulation 2 to 5 cm, moderate west wind, treeline temperature -5 C, freezing level 600 m.
MONDAY: Cloudy with snowfall, accumulation 15 to 20 cm, moderate to strong west wind, treeline temperature -1 C, freezing level 700 m rising to 1500 m over the day.
TUESDAY: Cloudy with rain, accumulation 60 to 80 mm, strong southwest wind, treeline temperature 2 C, freezing level 1500 m.
WEDNESDAY: Morning snowfall then clearing, accumulation 10 cm, light to moderate northwest wind, treeline temperature -5 C, freezing level 500 m.
Avalanche Summary
The recent storm snow was reported to have produced small avalanches on Sunday. As the next storm arrives, avalanche activity is expected to spike when the freezing level rises and snow switches to rain. This switch will rapidly destabilize the snow and increase the likelihood of wet avalanches below the snow line and storm slab avalanches above the snow line.
Snowpack Summary
Around 40 to 60 cm of snow fell above around 800 m on Sunday. This snow overlies a melt-freeze crust up to about 1500 m or hard wind-affected surfaces at higher elevations. The next storm on Monday afternoon will drop another 15 to 20 cm of snow before the freezing level rapidly increases on Monday afternoon to 1500 m. The rise in freezing and switch from snow to rain will rapidly moisten the snow surface late Monday.
Terrain and Travel
- The first few hours of rain will likely be the most dangerous period.
- Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
- Travel in alpine terrain is not recommended.
Problems
Storm Slabs
Upwards of 40 to 60 cm of snow accumulated in the region on Sunday. This amount of snow will need some time to stabilize. A rapid air temperature increase and switch from snow to rain is expected on Monday, which could make storm slabs more touchy to human traffic. Conservative decision-making is essential to avoid this problem at and below treeline.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Best to plan your day to be back at the trailhead when the precipitation switches from snow to rain. The rain will rapidly destabilize the previously dry snow and increase the likelihood of wet loose avalanches. Plan your route to avoid overhead exposure.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Jan 6th, 2020 5:00PM
