Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

The likelihood of a very large avalanche ticks downward each passing day without a new event.  However, the consequences of a deep slab avalanche remain the same and should still dictate how you travel.  Avoid traveling on large open slopes and limit your overhead exposure throughout the weekend.

Avalanche problems

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3

    Very large, natural avalanches have occurred as recently as Sunday or Monday with more recent avalanches in other zones. Deep persistent avalanches can destroy cars and houses and can occur with no warning.  This type of avalanche would be unsurvivable no matter your mode of travel.  

    Every day without a new deep slab avalanche is a step in the right direction.  Much cooler temperatures are on the way, also a welcome sign following several days of above freezing temperatures.  A trend in the right direction is not enough to overcome the uncertainty and high consequences surrounding this type of problem.  Be intentional about where and how you travel.  If you flip through some of the photos in the media reel below, you'll see some of these avalanches have coursed thousands of feet and through areas you might not normally think twice about stopping.  

    The way to stay safe is simple: Avoid traveling in or under large avalanche paths. Avoid leeward slopes 35 degrees and steeper where the wind drifted slabs in the past week. Use extra caution on any steep slope, even around sparse trees. Before you commit to traveling in avalanche terrain, ask yourself, "What's the largest avalanche that this slope can produce, am I willing to take that risk, and is there a safer option?"

    (3/1/2021) A very large avalanche (D3) was triggered by WSDOT highway forecasters on March 1st in a portion of the West Camp path on Rock Mtn. Adjacent sections of this avalanche path ran naturally on Feb 26th. Photo: WSDOT

Avalanche Discussion

The start of March marked a change from our cold and snowy February with mild temperatures, periods of sunshine and freezing levels hovering between 5000-7000'.  A weather system brought increasing winds Friday along the east slopes of the Cascades but very little in the way of new snow.  Only a dusting to an inch or two of snow is expected through Saturday morning.  Snow levels are expected to drop significantly overnight through Saturday.   Cooler temperatures should help decrease the chances of cornice fall over the weekend. 

February 25-26th brought a storm with ~2" of water equivalent at the Cascade Crest and extreme winds. This came on the heels of an even bigger storm. From Feb 20-23rd a massive storm brought up to 6" of water equivalent to the mountains near the crest but much less to the Wenatchee Range further east. Numerous deep and very wide avalanches (Many D3-3.5's, some size D4's)  ran on, or around the 22nd in the mountains near the crest, and some deeper slabs were reported from the Wenatchee Range. Similar-sized avalanches continued earlier this week. An observer on Wednesday reported widespread very large avalanches in the Chiwaukum range and the Icicle drainage from the most recent cycle. While conditions may be less dangerous in parts of the Wenatchee Mountains, due to less recent snow, the same weak layers can be found and recent avalanches have been triggered on them. In the northern end of the zone, near Holden, the mid-January weak layer is present, though it has produced inconsistent test results. An observer there reported that most avalanches from late February appeared to run on storm interfaces in the upper snowpack.

Recent notable avalanches:

3/1: WSDOT avalanche teams observed a recent (within the past 24hrs) natural D3.5 deep slab from high, north-facing terrain in the Chiwaukum Range. They also triggered an 8ft deep D3 in southeast facing terrain at around 6,000ft off Rock Mountain east of Stevens Pass (the remaining hangfire in West Camp path). Chair Peak at Snoqualmie Pass ran as a D3.5 at some point between Sunday night and Monday morning (3/1) with a crown 10-15'+ deep. An observer reported numerous very large avalanches near Fortune Peak, just west of this zone.

2/28: A fairly fresh-looking deep persistent slab avalanche from upper elevation terrain was spotted in the Chiwawa drainage. 

2/26-27: A natural D4 avalanche released from Rock Mtn and came just short of Highway 2. A couple of D2.5-3's terrain in Icicle Creek (see photo below).

2/24: A deep persistent slab occurred on a south aspect near Manastash Ridge. 

Check out the Conditions blog for a more comprehensive and regional summary of very large avalanches that have released throughout the central and southern Cascades over the past two weeks.

Regions covered