NWAC

NWAC

Snowpack Analysis

A weak moisture band spread some light snow northward over the south-central Cascades overnight and early Sunday with little accumulation along with generally light winds and continued relatively low freezing levels. Otherwise, further slow snowpack settlement at relatively cool temperatures continues to gradually decrease the avalanche danger from the recent rather sensitive wind slabs that were reported on many steeper slopes late last week into Saturday…with settlement rates of the new snow now reaching upwards to 50 to 60% or more. Also, a weak surface crust developing overnight has briefly decreased the danger early Sunday on previously sun exposed terrain.

However, strong winds near higher ridges Friday through early Saturday helped create some new 1-2 ft wind slabs on west exposures while cross loading some south facing terrain. The effects of such winds may have been responsible for two recent avalanche accidents near Kendall Peak on Friday and Granite Mountain late Saturday. Apparently the Kendall Peak slide to the northeast of Alpental involved wind hardened snow over some weaker layers formed early to mid week last week while the Granite Mt incident to the west of Snoqualmie Pass involved a skier or boarder triggered slab on a cross loaded south facing slope that caught a hiker when it descended across a trail at lower elevations. Although significant injuries were involved with theser incidents, both victims are expected to recover and we wish them and their families the very best. In any case, slopes showing evidence of recent wind effects should be approached with caution, especially in areas showing no evidence of recent avalanche activity.

Also of note are the very large recent cornice buildups along ridges that should be susceptible to failure during daytime warming or from unwary recreationists venturing too close to their edge.

Finally, way too many people have skirted disaster and relied on luck for surviving accident involvements over the past week. Relying on luck is anything but reliable in avalanche terrain, and backcountry travelers should use extra caution, cautious routefinding and conservative decision making until the recent deep snows are able to consolidate and stabilize further. While this remains early spring, the increasingly strong spring sunshine can and does change stability of new snow very quickly.