Avalanche Forecast

Light to moderate snow showers at cool temperatures are expected overnight and early Sunday before tapering through the day. Winds should be light, except light to moderate in the alpine.

Only light accumulations of new snow are expected and with cold temperatures and light winds this should not affect the current avalanche danger significantly. The avalanche danger should gradually decrease on Sunday. However, cold temperatures may help maintain older wind slab and isolated storm slab layers.

Heightened avalanche conditions are expected on specific terrain features, such as steep wind loaded slopes and steep unsupported slopes, or cross loaded features. Avalanche conditions are expected to gradually improve, however, evaluate snow and terrain carefully and avoid features or slopes of concern Sunday.

Recent moderate to strong S-SW winds will make wind slab most likely on northwest to southeast slopes, but keep an eye out on all aspects in areas of more complex terrain. Watch for firmer wind transported snow from Friday and possible deeper wind transported layers. Older wind slabs may be masked by shallow fresh snow.

Cornices won't be listed as an avalanche problem in this area, but avoid travel on ridges, where recent cornices may have formed and avoid slopes below cornices.

Weather and Snowpack 

The most recent warm, wet storm arrived on Valentines Day 2/14 forming a strong rain crust, now buried 2-5 feet or more in some areas. 

A series of disturbances in cool, NW flow aloft from Saturday 2/25 through Tuesday 2/28 deposited 1.5 - 3.5 feet of snow along the west slopes of the Cascades. Very strong alpine west winds were seen in most of the Olympics and Cascades on Tuesday.

Southwest flow aloft began to ramp up again on Thursday as the first in a new series of fronts crossed the Northwest. Strong southwest flow carried a second stronger front across the Northwest on Friday evening. Along the Cascade west slopes this caused strong southwest alpine winds, heavy, moist, dense new snow above about 3-4000 ft and wet snow or rain below about 3-4000 ft.

A widespread avalanche cycle occurred late Friday and Friday night in many areas along the Cascade west slopes.

Mt Baker area received over 2 feet of new snow as of Saturday morning, with an additional 8-12 inches by Saturday afternoon.

There was widespread natural and human triggered large avalanches reported in the Mt Baker backcountry from late Friday through early Saturday.

Recent Observations

North

NWAC observer Lee Lazzara reported that extensive avalanche control was needed in the Mt Baker ski area on Friday but further detail are not currently available. Lee found an upside down warmer, wetter over drier, weaker profile and that test columns were failing on isolation in storm snow layers. A general top of the snowpack profile was 30-40 cm of 1F+ over 4F snow.

Widespread 1-2 ft storm slabs and larger, 3-5 foot wind slabs were seen in the backcountry near Mt Baker. A close call occurred on Mt Herman when a large wind slab was triggered, and partially burying two and fully burying one in a separate party at the base of the slide path after completing a run. It was a fortunate outcome with no significant injuries. We hope to get a more detailed report soon.

Lee was back in the area Saturday and the previously seen layer of strong wet snow layer over weaker snow was down about 2 feet. Storm slabs were sensitive Saturday and as a result travel was confined to low angle slopes away from any terrain of consequence.  

Central

NWAC observer Jeremy Allyn was in the Alpental Valley on Thursday and found storm snow instabilities still present and slowly stabilizing. Thin wind slabs were forming in the upper portion of the below treeline band and showed signs of increasing sensitivity.

The Stevens patrol reported widespread 6-8" ski triggered storm slab on Friday morning. Sensitive loose wet ski tests were also seen below about 4500 ft.

NWAC observer was also at the Stevens ski area on a day off from the NWAC but reported upside down wetter over drier snow conditions.

Extensive 4-14" wind slab triggered by explosive control turned into wet debris at Alpental on Friday morning.

Dallas Glass was in the Alpental Valley Saturday and reported that previous moist to wet snow was settling and less reactive. The earlier storm slab problem was rapidly improving in this zone.

Wind slab,1-2 feet, ski triggered while ascending the ridge, Arrowhead Peak, east of Stevens Pass, 5500 ft elevation, SW aspect. No skier involvement. Photos: K. Johnson

South

No recent observations.