Avalanche Forecast
Issued: Apr 23rd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Loose Wet and Deep Persistent Slabs.
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Avalanche Canada
It's a challenge to manage different avalanche concerns that vary by elevation and aspect. Observe local conditions and use that information to help select terrain and travel techniques. Expect continued snow up high, rain down low, and a sloppy mix in the middle. Warm temperatures, rain, and the lack of overnight freeze zaps the strength out of the snow.
Summary
Confidence
Low
Avalanche Summary
No new avalanches reported. Please remember there are few eyes still out there regularly reporting field observations.
Expect Storm Slab or Wind Slab avalanches on Monday where more than 20 cm of new snow accumulates. At low elevations avalanche activity is likely to increase as low elevation snow becomes saturated by rain.
Snowpack Summary
Snow continues to accumulate at high elevations. Generally this recent snow is settling and bonding about as fast as more arrives. However, heavy localized snow could mean accumulations greater than 30 mm water equivalent (30 cm) in some valleys (but generally only 10 to 20 mm in the region as a whole. Storm slabs may develop in favoured snow holes. Windslabs are possible in immediate lee features.
On solar aspects at all elevations, and north aspects at treeline and low elevations, there are many crusts in the upper snowpack. Watch for this snow sitting on a slippery crust. Watch for the snow quickly loosing strength and loose wet avalanches when the sun pokes out.
At mid and high elevations the middle of the snowpack is generally well-settled and strong. A weak layer of facets at the base of the snowpack remains a concern, primarily in alpine terrain with shallow or variable (thick and thin) snowpack depths but also where there's overhead hazard (for example from cornices).
At low elevations the snowpack is generally melting away; however avalanche danger can exist from overhead hazards (avalanches starting from up high above near the peaks) or melting (warm temps, sunshine, rain).
Weather Summary
Sunday Overnight
Cloudy. Precipitation 5 to 10 mm falling as snow in the alpine, rain down low, and sloppy snow in between. Light winds. Treeline temperatures around zero and freezing level around 1500 m.
Monday
Mostly cloudy. Trace to 5 mm water equivalent of precipitation (rain low, sloppy snow around treeline, snow alpine). Freezing level remaining between 1500 to 2000m. Treeline temperature around zero. Light westerly wind.
Tuesday
Generally clearing up and drying out kind of day. Trace to 5 mm water equivalent of precipitation. Ridgetop wind light but gusting moderate from the west. Around -5 C at treeline with freezing level around 1500 m.
Wednesday
Mix of sunshine with cloud arriving in the afternoon and precipitation starting up. A trace to 5 mm of water equivalent of preciptiation. Moderate southwest wind, freezing level around 2000 m, treeline temperature around zero.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
- Be alert to conditions that change with elevation and sun exposure.
- Shooting cracks, whumphs and recent avalanches are strong indicators of an unstable snowpack.
- Be carefull around freshly wind loaded features.
- Investigate the bond of the recent snow before committing to your line.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Storm Slabs
New storm slabs are possible at high elevations where dry winter snow might be found. Dial back your terrain choices if you encounter more than 20 to 30 cm of new snow. Watch for this snow sitting on a slippery crust on solar aspects. Watch for deeper wind slabs on lee features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Warm temperatures, including little overnight freeze, and wet snow or rain could trigger sliding in the recent snow on slippery crusts and at low elevations.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. Thinner snowpack areas and areas with variable thick and thin coverage at alpine elevations is where this problem is most likely found. April's warming temperatures may gradually increase the sensitivity of this layer, especially in thin snowpack areas.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 24th, 2023 4:00PM
