Avalanche Forecast

Issued: Feb 15th, 2015 7:30AM

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

jlammers, Avalanche Canada

Northwest Inland.

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Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

A dry ridge of high pressure will maintain a mix of sun and cloud for Monday and Tuesday. A weak trough will bring increased cloud and light snowfall on Wednesday evening. Winds should remain mainly moderate from the west-northwest. Freezing levels should hover around 2000m on Monday and Tuesday, and then jump to about 2800m on Wednesday.

Avalanche Summary

On Saturday, loose wet avalanche activity to size 2.5 was observed. With forecast warming and solar radiation, I would expect ongoing loose wet activity with the potential for wet slab avalanches and cornice failures.

Snowpack Summary

In the south of the region, generally light amounts of new snow overlie a hard crust which extends to about 1800m. This melt-freeze crust is adding considerable strength to the snowpack, although warming may weaken the crust allowing for surface avalanches to fail more easily. About 20 or 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. In general, the mid and lower snowpack are strong and well-settled. Further north in the region, freezing levels have generally been lower during recent storms. In these areas, new wind slabs are also a concern and deeper persistent weaknesses are more likely to exist.

Problems

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.

Be alert to conditions that change with aspect, elevation and time of day.>Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

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

Be alert to conditions that change with elevation.>The new snow may require several days to settle and stabilize.>Avoid travelling in areas that have been reverse loaded by winds.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 16th, 2015 2:00PM