Avalanche forecast

East Slopes Central

Northwest Avalanche Center
View on map

Avalanche danger

Tue
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Out of date — this forecast expired 3 years ago.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

Some new snow and moderate winds are in the forecast, and you could trigger avalanches that run on weak snow or slick crusts. We expect most avalanches to be small, but they could be consequential in very steep or exposed terrain. Stick to low-angle slopes if you see signs of instability, such as shooting cracks, recent avalanches, or actively blowing snow.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Yet another storm favoring the eastern slopes of the Cascades may bring a round of snow with moderate winds to the zone. Favored areas, particularly the Wenatchee Mountains, may pick up 5-8 inches of snow by the end of Monday. Recent warm, sunny weather with cool nights means there are slick crusts on southern aspects and surface hoar or weak snow on northerlies. New snow may not bond well with these old surfaces, so while we don't expect large avalanches, they may be easy to trigger and propagate wider than you expect. Avalanches will be larger and more consequential in areas where the wind drifts the snow deeper, such as lee slopes below ridges and the base of cliffs. Use small test slopes and quick hand pits to check on the recent interface and observe how easily snow slides. Choose more conservative and lower-angle terrain if you see shooting cracks or the new snow slides easily off the old surface. 

    (1/8/2023)

    Shooting cracks, like in this example, is a bullseye observation that the new snow is unstable.

    Photo: PKS

Avalanche Discussion

We just had our spring weather teaser, and now we'll return to something a bit more like winter. With a myriad of weak or slick surfaces and significant variability in snow totals from east to west, stability is likely to vary across the zone. With these easterly storms, there is also a potential that we will get more or less precipitation than the weather models suggest. So be prepared to adjust your travel plans and move to lower-angle slopes if you see red flags of instability, such as collapsing, shooting cracks, recent avalanches, or heavy snowfall rates. At the lower elevation trailheads, precipitation may fall as rain, and where there is still dry snow available small wet loose avalanches are possible. 

The recent snow has piled deep over a couple of intermittent sun crusts and a pair of rain crusts from Valentine's Day, which are around 3-5ft deep. This crust extends to just below 7000ft with some weaker snow beneath it, and observations indicate wide variability in the structure and depth of this layer throughout the zone. The MLK crust is down 4-6ft and extends to higher elevations. Very large avalanches that occurred on the 10th on Cannon Mountain, Rock Mountain, and North Chiwakum may have run on one of these crusts or some other deep layer. It has been over a week since any new, very large avalanche occurrences, and we don't expect to see any additional activity on deeper, old snow layers. Still, since we have yet to definitively ID the weak layer or interfaces in these slides, it's worth considering if you step out into steep, complex, northerly alpine terrain.

Regions covered