Avalanche forecast

East Slopes Central

Northwest Avalanche Center
View on map

Avalanche danger

Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Another round of moist new snow is expected on Wednesday. As temperatures warm during the day, be on the lookout for wet avalanches from steep slopes at lower elevations. Slab avalanches on an old crust/facet layer could be 2-3ft deep and surprisingly wide on large terrain features, so stick to lower angle and well supported slopes forthe time being.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–2.5

    The base of the snowpack is weak. A complex of facets and decomposed crusts that were buried around the Solstice have continued to cause avalanches for a couple of weeks.Identify large, steep terrain features steer away from. An unlucky individual could hit the wrong spot on a steep slope, and the whole slope may fracture and slide. It may not be the first skier or rider on the slope, but it could be the second or third. You could trigger one from low-angle terrain below or adjacent to steep slopes. Because of this, your best strategy is patience and conservative travel choices. Give yourself wide safety buffers around big complex terrain features where a small slide could step down to deeper layers.

    This problem is not limited to only the Wenatchee Mountains, but it's where all the recent reported activity has taken place. Further west, these slides have become more difficult to trigger. Although the weak structure still exists, it's just more deeply buried. If you got unlucky, or a cornice drops, a 2-4ft deep avalanche could result, and it would be surprisingly destructive. 

    (1/20/2024)

    This avalanche that failed on the Solstice Crust was triggered by a skier on Saturday on Diamon Head, Blewett Pass. Notice the older crown to the left in the photo.

    Photo: Brett Hlavka

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Warming temperatures and rain on snow kicked off a round of wet avalanches on Monday, and these should continue as the daytime warms on Wednesday. Slides could run easily on the crust that forms overnight, and may entrain the new snow. Wet slab avalanches could also occur, and these would be larger and wider than loose slides. If any slide stepped down to become a wet slab, it could be 1-2 ft deep.

    Wet avalanches often start from trees or rocks shedding snow onto slopes below, but you can also trigger them with your skis or snowmobile. Look for signs of instability that include rollerballs, or fresh wet slides. It'll be a good day to keep track of snow surface conditions. If you find wet and sticky surfaces, stay off steep and consequential slopes.

    (1/23/2024)

    Wet slide debris in one of the chutes near Whitepine Rd off Hwy2.

    Photo: Matt Primomo

Avalanche Discussion

Another round of dense new snow is expected for Wednesday morning. We're expecting more snow in the southern and western portion of the zone, like the Salmon la Sac. If you venture out and find over 6" of new snow, check for storm slab instabilities like cracking and small slab avalanches.

On Tuesday, warm temperatures continued to creep into the zone, and the lower elevation snowpack has begun a transition to wet grains, at least near the surface. A widespread wet loose cycle was observed at nearby Stevens and Snoqualmie Passes. A small wet slab ran naturally on the access road to mission Ridge on Monday. Many areas picked up 5" or so of new snow on Monday before the temperatures began their warming trend. Water amounts varied, but Mission Ridge received a whopping 0.8" of SWE on Monday. 

I was out on the 22nd and 21st in the far western edge and the eastern edge of the zone. Although the snowpacks ranged in depth from 150cm in the upper Icicle to only 100cm in the Blewett Pass area, there were certain commonalities that are worth discussing. First, there is a substantial amount of new snow since January began (2-3ft). Second, we could identify a weak structure near the base of the snowpack that consisted of faceted grains over and often beneath a weak, decomposed crust (2-3ft down). Third, snowpack tests showed the potential for avalanches to propagate on this layer in both locations.

The Solstice Crust/Facet Complex in the Wenatchee Mountains has been active since late December and has continued to produce avalanches. Human triggered avalanches on this persistent weak layer have occurred on Jan 6th, 12th, 15th, 19th, and 20th. On Saturday in nearby East South, a rider remotely triggered an avalanche near Manastash Ridge that we suspect ran on this layer. While these avalanches have primarily occurred in wind-loaded terrain, we can't rule out avalanches in sheltered areas, especially as temperatures climb and we receive more precipitation.

If you get out, let us know what you see by submitting a public observation!

Regions covered