Two Teenagers killed in Alpental Valley

Accident report here .

2/25/18 Source Lake-Snow Lake Divide, Alpental Valley, Snoqualmie Pass area, WA Two teenagers were killed by a slab avalanche that released on a south aspect at 4250 ft in the Alpental Valley. The avalanche initiated just below ridgecrest at the final steep switchbacks of the summer trail to Snow Lake Divide, NE of Source Lake. NWAC staff investigating on 2/26 estimated the avalanche 350 ft wide and that it ran 500 vertical ft into mature timber with crown depths up to 36" (85 cm). The failure interface was a layer of small facets above a thin melt-freeze crust that was buried by storm snow on 2/23 (SS-U-R3-D2.5-I).

Thoughts on this? Avalanche forecast is lowered to moderate but it sounds like that persistent layer is still very sensitive. Glad I got some touring in before that layer set in.

RIP to the boys. Hope those families get through the hard times to come.

If the boys were on the summer trail then that is not the suitable ascent route in winter.  I recall a party of 2 snowshoers being killed in an avalanche there several years ago early season, NWAC report of 12/02/07. 

media.nwac.us.s3.amazonaws.com/media/fil...alanche_accident.pdf

Sad news, my condolences to the boys families who must be devastated.

If the boys were on the summer trail then that is not the suitable ascent route in winter. 

I've used the trail a number of times in the winter without problems. I just don't go when there is an avalanche warning/high danger posted.

Still, really sad. I was glad to see all my students back in class today.

.... I just don't go when there is an avalanche warning/high danger posted.

^This.

There are innumerable slopes or terrain features that can have serious avalanches depending on conditions. A surprisingly small amount of snow can generate a fatal injury. Rembering Don Hanson

Simply avoiding all high potential terrain whatever the condition is not a guarantee of safety. Awareness of terrain and conditions allows one to manage risk and make better choices.

To be fair to these snowshoers, the summer trail commits you to far less avalanche terrain than climbing up underneath chair peak basin from source lake. Although the final pitch on the summer trail is fairly steep. Huge slides come out of chair peak basin and BPC area every year and often times multiple times a year.

I think skiers are so used to the common winter ascents routes that they assume they are more safe. But in reality you are climbing up underneath some of the most intense terrain in the area where things could be triggered well over 1000 feet above you. I wonder how many snowshoers, who only take the summer route, make the same judgement about skiers who climb up underneath chair peak.

Pick your poison. What was the actual avalanche forecast for the 25th? I don't recall it being high. I believe it was considerable or moderate.

For me I feel like northwesterners haven't groked that persistent layers are unpredictable and hard to test. At one point this week NWAC lowered the forecast to moderate yet we were still getting reports of moderate sized slides naturally occurring back down to that persistent layer. If our argument is that they made a poor terrain choice and that the better alternative would be to climb the snow-lake divide via source lake we perhaps are missing the lesson to learn here.

For me I am content with riding resort until that thing strengthens. I am looking forward to getting back to normal moderate NWAC forecasts with ridge top wind concerns and storm slab. You know, normal PNW stuff.

I agree, both routes have their hazards and giant slides can and do come down through from Chair Peak. Rating for Sunday issued on Saturday was High/High/Considerable upgraded on Sunday morning to High at all elevations. Travel in that basin on either route was dangerous although I have no idea if the chair peak slide path went or not over the weekend as I wasn't there. I think you are less likely to human trigger an avalanche on the winter route but a natural one would be large enough it would kill you although again, its possible to mitigate most of this exposure with an ascent off the main slide path. The trees on that slope are all flagged though so it all goes at some point.