Avalanche Forecast

You can trigger recently formed Wind Slabs at upper elevations. Stay safe by avoiding obviously wind loaded features. Cracking in the snow, stiff, supportive surfaces, and wind sculpted features are all indicators that you should avoid a piece of terrain. Very strong and gusty winds may have formed slabs where you would not normally see them. Use caution in areas that could be cross-loaded mid-slope. If you venture above treeline, know that observations have been minimal at that elevation for 2-3 weeks. Use caution and take time to assess the upper snowpack and any recently drifted snow.

Large cornices exist along ridgelines and have been sagging recently due to warming. Give cornices a wide birth and limit your exposure as much as possible if you must travel under them. Cornice fall is unpredictable. Use caution on steep, icy terrain. With recent rain and freezing, many slopes may be firm and slick. While not an avalanche concern, a slip and fall in steep terrain above rocks or cliffs could be dangerous.

Gusty westerly winds drifted snow from Sunday night through Thursday. Generally 3-7 inches of snow accumulated on the most recent melt-freeze crust near and above treeline. The crust formed up to 5800-6800 feet in the northeast Cascades. Significantly less snow fell to the east and south.

A natural avalanche cycle was reported in many areas from Monday’s (1/29) warm and wet weather with some of these avalanches triggered by cornice fall. Rain occurred along the east slopes as far north as Holden Village, WA.

In the the last week of January observers reported isolated buried surface hoar on top of the 1/16 crust. This persistent weak layer was found or thought to be the cause of several avalanches. Though it’s no longer a main concern, use caution when traveling in areas further east of the crest where this layer may survive. Snow profiles and snowpack tests are the best means to confirm or deny the presence of this layer.

Observations

North

On Friday, avalanche professionals near Washington Pass triggered a small slab avalanche in recently drifts above treeline, and a few small loose dry avalanches in steep upper elevation terrain.

Thursday, avalanche professionals in the Washington Pass area traveled to near treeline. At 6000ft they found 4 inches of new snow on a recent crust. Wet snow and rain fell at lower elevations with rain to 4500 ft. Strong crest level winds were transporting snow, but due to the gusty nature, wind slabs were not uniformly deposited.

Central

An avalanche professional traveling in Icicle Creek Thursday found 6-8” of settled snow well bonded to the 1/29 crust. Observations showed a strong upper snowpack. No buried surface hoar was found in this location.

On Tuesday, Mission Ridge Pro Patrol identified several layers of concern in this regionally shallower snowpack. These layers should be watched during future loading events. Similar basal weak layers were found in the nearby shallow snowpack of Blewett Pass.