Avalanche Forecast
Issued: Apr 18th, 2019 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Loose Wet.
mconlan,
Avalanche Canada
Conditions will vary rapidly with elevation. Watch for loose wet activity below the rain-snow line and touchy wind slabs above. Travel conservatively during Friday's stormy conditions.
Summary
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
THURSDAY NIGHT: Cloudy with rain, accumulation 10 to 20 mm, moderate to strong southwest wind, alpine temperature 1 C, freezing level 2500 m.
FRIDAY: Cloudy with alpine snow, accumulation 5 to 15 cm, moderate west wind, alpine temperature -1 C, freezing level 2200 m dropping to 1800 m.
SATURDAY: Mix of sun and clouds with isolated flurries, light north wind, alpine temperature -3 C, freezing level 2000 m.
SUNDAY: Mostly clear skies, light south wind, alpine temperature -3 C, freezing level 2100 m.
Avalanche Summary
Small (size 1) storm slab avalanches were triggered naturally and by a skier on Wednesday. They were in alpine terrain, 20 to 30 cm deep, and on north to east aspects.
Snowpack Summary
The freezing level rose to around 2500 m on Thursday, moistening the snowpack on all aspects. Above 2500 m, around 10 to 20 cm of snow may accumulate on Thursday night, with rain below. Another 5 to 15 cm of snow may accumulate above around 1800 m to 2200 m on Friday. Where the precipitation falls as snow, it may form touchy slabs on Friday, particularly in exposed areas due to strong southwest wind.
Weak and sugary faceted grains may remain at the bottom of the snowpack in the alpine, producing a low likelihood but high consequence scenario. Steep, rocky areas with a shallow snowpack are the most likely places to trigger this layer.
Problems
Wind Slabs
Snow depth will change dramatically due to a variable freezing level. Expect touchy slabs above the rain-snow line, somewhere between 2000 m and 2500 m. Use particular caution in lee features near ridges where deposits will be the deepest.
- Be careful with wind-loaded pockets, especially near ridge crests.
- Expect conditions to change rapidly with aspect and elevation.
- Use small slopes without consequence to test the bond of the recent snow.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
The likelihood of loose wet avalanche activity should increase due to rain, particularly where it falls on previously dry snow. Best to avoid steep slopes during and after periods of rain.
- Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.
- Minimize overhead exposure and avoid steep slopes during periods of rain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 19th, 2019 2:00PM
