Archived

Avalanche Forecast

Mar 24th, 2014–Mar 25th, 2014

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

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Glacier.

Solar radiation this morning is expected to be cut out by cloud cover but a thin layer of cloud could increase the solar affect. Manage your groups exposure to overhead hazard accordingly.

Weather Forecast

Weakening ridge of high pressure over the interior will mean increasing cloudiness today. No precipitation is expected until Tuesday night when a Pacific system makes it way over to us. Light to moderate amounts are expected then with rising freezing levels,.

Snowpack Summary

The upper snowpack will vary depending on aspect. North and east will have settling snow, south and west will have the Mar 22 crust down 10cm. The Mar 13 crust down 45-65 and the March 2 CR/SH layer down 1m. Tests show hard sudden result on the Mar 2 layer, propagation tests still show large potential for propagation. The Feb10 layer is down ~2m.

Avalanche Summary

No new avalanches yesterday observed or reported in the park yesterday. On Friday a size 3.5 natural avalanche released in Grizzly Bowl, SE asp, ~2600m, presumably from a cornice trigger. These sporadic events keep our guard up.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Avalanche Problems

Storm Slabs

Storm slab instabilities newly formed soft slab in the lee of ridge crests may exist and pop with human triggering.

Be cautious as you transition into wind affected terrain.Caution in lee and cross-loaded terrain near ridge crests.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Persistent Slabs

Snowpack tests yesterday show the Mar 2 layer down ~1m to still be reactive with large consequences if triggered. Shallow snowpack areas, like slopes that have lots of rocks poking out, seem to be the most likely areas for this to happen.

Avoid shallow snowpack areas where triggering is more likely.Choose well supported terrain without convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3

Deep Persistent Slabs

Another deep weakness in the snow pack is the February surface hoar/crust layer. Large triggers, such as a cornice fall or a running avalanche, will be needed to step down to this layer.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely

Expected Size: 3 - 4