Avalanche Forecast

Recent snowfall this week will still be susceptible to strong spring solar effects and daytime warming on Saturday despite the cool snow levels forecast. Watch for wet surface snow deeper than a few inches, natural or triggered snowballing, and small natural wet loose avalanches which usually precede larger avalanches on solar slopes. For slopes receiving more sunshine on Saturday...recent heavy snow at higher elevations will quickly become available for larger wet loose slides. 

Wind slab may persist on Saturday on cooler lee slopes mainly above treeline and on non-solar aspects. Watch for signs of firmer wind transported snow or cracking snow. 

Despite the cool temperatures recent loading and daytime warming will continue to stress cornices.  Give them a wide berth and avoid travel below them...especially in the afternoon. 

A frontal system Saturday night followed by moderate to potentially heavy showers on Sunday may increase the avalanche danger on Sunday. 

The last full week of April has felt more like winter than spring; the Forks, WA freezing level has averaged 4300 feet over the last week which is almost a 1000 feet lower than the average for the entire month of March. Upper NWAC stations at Green Valley, Crystal Mt, Paradise, MRNP, top of Alpental (measured by ski area), Snoq Pass, Pigtail Peak, White Pass, and Timberline, Mt. Hood are all experiencing a second snowdepth maxima with snowdepths equal to maximums from late March or the first week of April. While your favorite ski area or trailhead parking lot might be looking a bit sad this time of year...keep in mind there's still plenty of snow the higher you go.

Water equivalents at NWAC stations near and west of the crest for the 4 days ending Friday morning are in the 1.5-3.5 inch range with the most at Paradise and Mt. Baker. Snowfall received during the span in the near treeline zone is in the 1-2 foot range with the most at Paradise and the top of Alpental, and with the implication of more snow at higher elevations.  East of the crest stations received about 0.5-1 inch of water during this 4 day stretch. 

Generally cold temperatures, light winds and light snow showers with sunbreaks were seen on Friday...allowing for gradual settlement of this week's snow but also potentially preserving any recent wind or storm slab instabilities in the above treeline zone especially on non-solar aspects.  

Avalanche observations from the past week (note that we receive far less observations than during winter): 

Washington Pass: The Washington Pass DOT crew reported 6 inches of new snow Thursday morning and an extensive natural dry loose avalanche cycle with some small storm slabs as well. Localized natural wet loose avalanches were seen in the afternoon. 

Alpental: The Alpental ski patrol reported a widespread natural avalanche cycle Wednesday night followed by easy ski triggering in the above and near treeline zone Thursday producing 8-12 inch storm slabs.  Large wet loose avalanches were easily ski triggered below treeline Thursday.

Chinook Pass:  On Thursday morning the DOT crew reported a large wet loose avalanche that reached the road entraining 12-16" of new storm snow and sliding on top of a thin crust formed Wed PM (see photo by John Stimberis, DOT). After an extended period of sunshine Thursday, a very large wet loose involved moist or wet snow from below the thin crust also reaching the road. Ski cutting produced easy results.    

Eastside: At lower elevations and further east of the crest there has been less recent precipitation and a few recent reports on Turns-All-Year describe more stable and spring like corn snow in the afternoons.