Avalanche Forecast

Issued: Mar 19th, 2022 3:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Persistent Slabs.

Avalanche Canada mkoppang, Avalanche Canada

Crusts on solar aspect are becoming more the norm. Dry snow is found on the more polar aspects but watch for windslabs in alpine areas. The sun has got some strength to it these days so keep in mind intense solar radiation and its ability to destabilize the snow. 

Summary

Confidence

Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

5-10cm of snow is forecast over the next few 24hrs with increasing winds out of the SW. Temperatures will again be dropping back into the cooler range with daytime highs on Sunday around -8C. Expect the sun to pack a punch tomorrow as clear skies are forecast and we can expect stability to deteriorate on solar aspects later in the day.

Avalanche Summary

One new cornice collapse on a N aspect near Burstall Pass parking area was observed. The cornice triggerred a sz 2 avalanche on the underlying slope that ran to valley floor. 

Snowpack Summary

Moist snow was found on solar aspects above 2000m. On steep solar aspects, there are two crusts of concern. A crust was formed in early March and is found about 30-40cm down and was producing a hard clean sheer in only one pit dug. The Feb 19 crust is down about 60-80cm. There is still uncertainty with the reactivity of these crusts. Take the time to dig and evaluate these layers on steep solar aspects. Otherwise windslabs in alpine terrain should be expected from the recent SW flow and 10-15cm that fell throughout teh day on Friday. These slabs are widespread above 2600m and more isolated below this elevation to ridgelines and gullied terrain. The sun packs a punch these days and when it comes out, stability quickly deteriorates on solar aspects. These effects are most apparent on steep thin solar aspects. Numerous cornices collapses have recent been observed also as temperatures warm up. 

Terrain and Travel

  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • Be alert to conditions that change with elevation and wind exposure.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Cornices become weak with daytime heating or solar exposure.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent winds have created windslabs in alpine areas. The slabs are more specific at treeline and below. Watch for areas where recent slabs are overlying a suncrust that can act as a perfect bed surface. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

Carefully evaluate the bond with the early March and Feb 19th crusts down 40 and 70cm. Recent wind loading will make this problem more reactive, as will periods of intense solar input.

Aspects: South East, South, South West, West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Mar 20th, 2022 3:00PM