Archived

Avalanche Forecast

Feb 15th, 2015–Feb 16th, 2015

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

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

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Glacier.

Cornices have grown to a healthy size over the last two weeks. Solar radiation today will make them hazardous to parties underneath them.

Weather Forecast

High pressure ridge over the Interior will keep things dry and mostly clear other than valley some valley cloud over the region for the next few days. Diurnal temperature swings with lows around -10 and highs around -2 at 1800m with generally light winds are forecast. No significant precipitation is forecast until the end of next week.

Snowpack Summary

The moist upper snowpack that we had grown so used to has finally begun to freeze. Expect crusty surface conditions and moist snow beneath it to ~2000m and settling storm snow in the alpine. The Jan 30 crust layer is down ~1-1.25m which formed a crust to 2200m. Jan 15 surface hoar layer is down ~1-1.5m. The mid and lower snowpack is well settled.

Avalanche Summary

Natural avalanche cycle yesterday morning from the previous nights rain had released several size 3 avalanches within the highway corridor and one size 3.5. Avalanche activity was extended yesterday afternoon when the sun came out releasing numerous loose avalanches to size 2.5 on sun effected slopes.

Confidence

Avalanche Problems

Storm Slabs

Recent storm snow has likely formed some soft slabs on and near ridge crests in the alpine.

Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Loose Wet

Solar radiation will be a factor to consider for the next few days. Manage your groups exposure to sun effected slopes and to the overhead cornice hazard. Watch for loose avalanches off of cliffs as indicators of instabilities.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2

Persistent Slabs

We have persistent weak layers down between ~1 to 1.5m. Large triggers such as a cornice failure or triggering from shallow areas may release avalanches these layers.

Avoid shallow snowpack areas where triggering is more likely.Cornices become weak with daytime heating.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 3 - 4