Avalanche Forecast
Issued: Mar 15th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Cornices and Loose Wet.
swerner,
Avalanche Canada
The March sun packs a punch and can quickly destabilize the snowpack. Storm slabs may continue to be reactive to human triggering, especially on wind-loaded northeast slopes.
Summary
Confidence
Moderate
Avalanche Summary
On Tuesday, a few human-triggered storm and wind slab avalanches were reported up to size 2. Natural cornice failures and dry loose avalanches were also seen to size 1.
On Monday, no new natural avalanches were reported. Numerous explosive-controlled cornice drops and storm slabs were initiated up to size 2.
On Sunday, in the Spearhead Range, a skier-triggered wind slab (size 1.5) caught and buried a skier to their knees. This occurred on a southwest aspect at 1800 m. The depth of the crown was 20-80 cm and 20 m wide. This skier was extracted by Whistler SAR with minor injuries.
Natural and human triggered avalanche activity may occur throughout the week with rising freezing levels and solar radiation.
Snowpack Summary
Surface snow will likely become moist solar aspects during the day and cornices loom over ridgelines. These may become weak during periods of intense solar radiation. Up to 35 cm of recent storm snow may have been transported by southerly winds in the alpine and at treeline. In sheltered areas, this new snow sits on top of two distinct surfaces. On solar aspects, a crust can be expected and on polar aspects, facets may be found. The recent storm snow may have a poor bond to the underlying surfaces.
Deeper in the mid-pack a couple of crusts with facets sitting above them can be found at treeline and above down 90 to 200 cm.
The remainder of the mid and lower snowpack is well-settled and strong.
Weather Summary
Wednesday Night
Clear. Alpine temperatures near -9. Wind from the east 15 km/hr and freezing level valley bottom.
Thursday
A mix of sun. Alpine temperatures near -4. Winds southeast 10-20 km/hr. Freezing level 1500 m.
Friday
A mix of sun and cloud. Alpine temperatures near -2. Wind southeast 10-20 km/hr. Freezing level 1700 m.
Saturday
A mix of sun and cloud. Winds 10-20 km/hr from the south. Alpine temperatures near -2 with freezing levels 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Closely monitor how the new snow is bonding to the crust.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
In wind-sheltered terrain, the recent storm snow may have a poor bond to the underlying crust.
Moderate to strong southwest winds have formed wind slabs on lee slopes at treeline and above and are more likely reactive to human triggering.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Large looming cornices exist along ridgelines. Cornices become weak with daytime warming and sun exposure. Give cornices a wide berth while traveling ridgelines and avoid slopes below them.
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Strong solar radiation and rising freezing levels may weaken the surface snow creating wet loose avalanches from steep solar slopes.
Aspects: South East, South, South West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 16th, 2023 4:00PM
