East Slopes Central

Wind slabs will become increasingly large and touchy throughout the day, potentially stepping down to weaker layers in the snowpack. Persistent slab avalanches remain primed for human trigger on steep, shaded aspects snowcovered foothills near Columbia River. As snow transitions to rain, expect potentially large natural wet avalanches on steep slopes.

A warmer, wetter storm will impact the East Central zone through Wednesday. This will add a difficult-to-manage mix of wet and dry snow problems. While conditions stabilized very slightly by Monday, the snowpack remains highly susceptible to more loading and a major warm-up after weeks of cold temperatures. Crusts formed by rainfall toward the end of the last storm cycle may limit the avalanche danger in some middle-elevation areas. Such crusts are less likely to be found in the eastern and northern parts of the zone. Mild temperatures over the weekend formed an additional surface crust, creating challenging "trap crust" travel conditions around Blewett Pass.

This system comes just days after the East Central zone received a record-breaking storm January 5-7 where many areas including towns picked up 3-4ft of new snow. Many large and very large avalanches occurred as recently as Saturday. Control at Mission Ridge pulled out a 3'-5' deep hard slab on the Solstice Crust, and 5' deep hangfire was easily triggered as well. Backcounry travelers over the weekend reported touchy conditions, and isolate whumphing near Mission Ridge on Saturday.  Debris piles were visible in many of the drainages in the lower Tumwater and Icicle Creek. Some of these avalanches were very large, carried trees with them, and one came within a few hundred feet of some houses. Folks reported whumphing collapses, shooting cracks, and a widespread avalanche cycle in the low elevation hills of the Columbia Basin on the 6th and 7th. 

On Thursday morning, a D2.5 slab avalanche damaged a house south of Entiat (SS-N-R3-D2.5-O). The front door and garage doors were damaged, and the slide buried a car in the driveway. The slide likely ran on depth hoar on the ground - see photos below. Tumwater Canyon remains closed, and WSDOT reported over 208 debris piles on Highway 2 up to 15 feet deep, and several ran into the river. 10 of those slides were very large. 8 very large slides over the road were reported in Icicle Creek. Roads have been hit by avalanches in many other areas including; Hwy 97A, Mission Creek, Olalla Canyon, and Entiat River rd. On Mission Creek rd a plow driver got caught between two debris piles, and needed larger machinery to plow out. There have been at least two roof avalanche burials in the past few days, both with lucky outcomes where the victims were dug out alive. Many roofs have been shedding and there have likely been many other close calls.

Observers documented many different weak layers in the zone prior to the storm. The recent layers were large stellars, facets and surface hoar from 1/2 and 12/29. A decomposing crust from the Solstice was the bedsurface for some slides at Mission Ridge. An even deeper crust from Early December was observed to have propagation potential on high elevation, shaded slopes in the Icicle drainage. At this point, these layers could be from 3-8ft deep, and act as the weak layer for slab avalanches.

Many great Observations have come in from the area. Thanks, and keep them coming as we unravel the saga of this epic storm and move into the next storm and avalanche cycle.