Archived

Avalanche Forecast

Mar 13th, 2013–Mar 14th, 2013

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

4: High

The avalanche danger rating below treeline will be high

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Glacier.

A strong storm bringing warm temperatures and high winds with heavy precipitation. Expect avalanches running to the end of the runnouts today.

Weather Forecast

A strong westerly flow will continue to bring moderate to heavy precipitation and high to extreme winds with rising temperatures through Thursday. This storm is expected to quiet down on Friday.

Snowpack Summary

30cm of new snow overnight on top of 15cm of recent storm snow has been very wind affected and has begun to form slab conditions. Below 1700m the Mar 3 rain crust, 3-4cm thick, is down 40cm. The Feb 12 surface hoar is down 120 to 150cm.

Avalanche Summary

A cycle of avalanche activity has begun overnight caused by rapid loading of the 30cm of new snow by the strong to very strong winds. Numerous avalanches have been observed this morning running to valley bottom.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Storm Slabs

A storm overnight has brought 25-30 cm of new snow with strong winds and rising temperatures. This has formed avalanche conditions.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 4

Persistent Slabs

The surface hoar/crust layer from February is most likely to be triggered by large triggers such as avalanches triggered in shallower layers in the snowpack and cornice falls which will result in large avalanches.

Sluffs may trigger deeper instabilities.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 4