Avalanche Forecast

Issued: Mar 10th, 2016 8:41AM

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

ccampbell, Avalanche Canada

South Rockies.

Intense solar radiation is expected to keep avalanche danger elevated tomorrow. Continued natural avalanche activity is possible.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

FRIDAY: Mainly sunny and dry with freezing levels back up to 2000m. Clouds are expected to roll back in early afternoon and winds should remain light to moderate southeasterly to southwesterly. SATURDAY Mainly cloudy with isolated light flurries possible, except east of the divide where it is expected to remain mostly clear. Freezing levels hovering around 2000m and moderate to strong southwesterly ridgetop winds. SUNDAY: Mainly sunny with cloudy periods, isolated light flurries possible with freezing levels dropping back down to 1700m and moderate to strong southwesterly ridgetop winds.

Avalanche Summary

Initial reports from Thursday include skier-controlled Size 1 fresh wind slab avalanches on the immediate leeward side of ridgecrests and terrain breaks. Natural wind and storm slab avalanche activity is expected on Thursday due to heavy loading from snow, wind and rain. On Friday, intense sun-exposure could trigger another round of natural activity, including cornice falls.

Snowpack Summary

10-15cm of fresh snow is bonding poorly to a widespread supportive crust. At higher elevations, touchy wind slabs linger below ridgecrests and behind terrain features in exposed terrain. Deeper in the snowpack, recent snowpack tests gave very easy sudden collapse results down 80cm on a southeast aspect at 1850m on the deep persistent facet/crust weakness from buried early December. Watch this weakness with extreme warming from sun-exposure, or warming/loading from rain. Cornices are also reported to be huge and weak.

Problems

Storm Slabs

Particularly deep and touchy on wind-loaded slopes at higher elevations. Expect increased sensitivity to triggering with sun-exposure.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>Be cautious as you transition into wind affected terrain.>The new snow will require several days to settle and stabilize.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Direct sun-exposure is expected to weaken large droopy cornices. Not only are massive cornice falls a hazard in themselves, but they can also act a heavy trigger for slab avalanches on the slope below.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Valid until: Mar 11th, 2016 2:00PM