Archived

Avalanche Forecast

Feb 14th, 2015–Feb 15th, 2015

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

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

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

Regions: Northwest Inland.

During recent storms freezing levels have varied significantly throughout the region. Pay close attention to conditions that change with elevation, aspect and geographic location.

Confidence

Poor - Due to the number of field observations

Weather Forecast

A ridge of high pressure will develop and bring mainly clear skies for the forecast period. Sunday: Light snowfall in the morning and then clearing throughout the day / Moderate to strong northwest winds / Freezing level at about 1200m Monday: Mix of sun and cloud / Moderate northwest winds / Freezing level at 1200m Tuesday: Mix of sun and cloud / Light northwest winds / Freezing level at 2500m

Avalanche Summary

Loose wet and wet slab avalanche activity to size 2.5 was observed in the last few days. If warm temperatures persist, there is ongoing potential for this type of activity to continue. Wind slabs to size 2 were also observed at higher elevations.

Snowpack Summary

In the south of the region, warming and subsequent refreezing may have created a hard melt-freeze crust which extends up to about 1800m. At higher elevations dense wind slabs are reported to exist. Where it exists, this melt-freeze crust should add considerable strength to the snowpack, although daytime warming will weaken this crust allowing for surface avalanches to fail more easily. About 20 to 40cm below the surface you may find weak surface hoar which was buried on February 10th. It is unclear if recent warming has destroyed this potentially weak layer. I'd dig down and test for this layer, especially at upper elevations where colder temperatures may have allowed for this weakness to persist. Further north in the region, the freezing level is reported to have hovered around 1300m during recent storms. In these areas, wind and storm slabs are a concern and deeper persistent weaknesses are more likely to exist.

Avalanche Problems

Storm Slabs

Recent storm accumulations may still be sensitive to human triggering, particularly in the north of the region or in higher, wind-exposed terrain. Storm slabs may take extra time to strengthen due to underlying surface hoar.

Be alert to conditions that change with elevation.>Be cautious as you transition into wind affected terrain.>The new snow may require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4

Loose Wet

Forecast warming and sunny breaks will increase the likelihood of loose wet and wet slab avalanches. Wet avalanches can be pushy and entrain mass quickly.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 4