Avalanche Forecast

Issued: Apr 6th, 2016 9:17AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Loose Wet, Cornices and Wind Slabs.

jlammers, Avalanche Canada

Sea To Sky.

Extreme warming and solar radiation will drive the Avalanche Danger. Be alert to conditions that change throughout the day, and watch your overhead hazard. Large avalanches may run farther than expected.

Summary

Confidence

High - The weather pattern is stable

Weather Forecast

A dry ridge of high pressure will bring mainly clear skies for Thursday and Friday. Increased cloud and isolated flurries are forecast for Friday evening and Saturday. The freezing level will sit at about 3800m on Thursday, 3300m on Friday, and 2300m on Saturday. Ridgetop winds will remain mainly light and variable.

Avalanche Summary

In recent days, fresh wind slabs to size 1.5 were triggered under light loads in mostly north facing alpine terrain. With forecast warming and solar radiation, we'll see a transition to more spring-like avalanche problems. Loose wet avalanches, and large cornice falls are expected throughout the forecast period

Snowpack Summary

20-40cm of recent snowfall overlies a mix of old surfaces that formed as a result of last week's big warm-up. These include hard crusts on high elevation solar aspects, settled dry snow in north-facing alpine terrain, and moist snow everywhere else. The recent snow has been shifted by strong southerly winds into fresh wind slabs in wind-exposed terrain. With forecast solar radiation and warm temperatures, most surfaces will transition to a daily melt-freeze cycle, while recently formed wind slabs will linger on high north-facing slopes. Below the new snow, the snowpack is generally strong and well-settled. Cornices are huge and will become weak with future warming and solar radiation.

Problems

Loose Wet

Rising freezing levels on Thursday will promote loose wet avalanche activity, especially in steep terrain when new snow is exposed to direct solar radiation for the first time. Be alert to conditions that change throughout the day.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be cautious of wet sluffing in steep terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Cornices

Some cornices are the size of a bus. As temperatures rise and sunny weather makes a come-back, these monsters will become more likely to fail.

Do not travel on slopes that are exposed to cornices overhead.>Give cornices a wide berth when traveling on or below ridges. >

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 5

Wind Slabs

Over the next few days, fresh wind slabs are expected to settle and gain strength. For the short term, I'd remain extra cautious of steep, wind-loaded pockets in the high alpine.

Travel on ridgetops to avoid wind slabs on slopes below.>Be cautious as you transition into high elevation wind affected terrain.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 7th, 2016 2:00PM