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Avalanche Forecast

Mar 26th, 2013–Mar 27th, 2013
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: South Rockies.

Be aware of changing conditions with daytime warming and sunny skies. Watch solar slopes and overhead hazards.

Confidence

Good

Weather Forecast

Mainly clear skies with some high-mid cloud cover and temperatures steadily increasing by the weekend.Wednesday:  Mix of sun and cloud. Treeline temperatures near -2.0. Freezing levels rising to 2200 m in the afternoon and then falling to 1200 m overnight. Ridgetop winds will be light from the West.Thursday/Friday: Partial cloud cover, then mostly sunny on Friday. Treeline temperatures near -1.0. Freezing levels will ride to 2200 m and then falling back to 1500 m overnight. Ridgetop winds will be light rom the SW.

Avalanche Summary

No new natural avalanche activity.

Snowpack Summary

Cornices are large and will likely become weak due to strong solar radiation and warming temperatures. Surface snow may become moist or wet up to 2200 m, especially on solar aspects. Melt-freeze conditions exist. Approximately 40-70 cm of settling storm snow sits on top of a buried rain crust down 50 cm and exists up to around 2100 m. In areas near Sparwood, the new snow initially bonded poorly to this crust, and a few large avalanches were observed that likely released on this layer. In the North Elk Valley, the bond at the crust was reported to be fairly good. Generally, this interface has now become stronger for all parts of the region. However, a large trigger such as a cornice fall or a skier/sledder hitting the sweet spot, could potentially trigger a large avalanche on this layer.Recent wind slabs exist in the immediate lee of ridge lines and terrain features.

Avalanche Problems

Cornices

Large looming cornices exist on most ridgelines. Cornices may become weak under the influence of the sun. They are a hazard in themselves and they could trigger slopes 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

Loose Wet

Clear sunny skies and warmer afternoon temperatures may promote deterioration within the upper snowpack. If surface snow becomes moist or wet, loose wet avalanches are likely. Watch solar aspects.
Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Watch for wet loose or slab activity.>

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

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 4

Wind Slabs

Wind loaded and cross-loaded slopes can still be found at treeline and alpine elevations. There is still a chance a small wind slab avalanche could step down to the March 16th rain crust.
Avoid cross loaded features, especially in the alpine.>Whumpfing is direct evidence of a buried instability.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4