Turnagain Pass Avalanche Forecast

A skier-triggered avalanche reported yesterday and a snowmachine-triggered avalanche on Sunday point toward a snowpack that still warrants caution and respect.  Wind slabs 1-3’ in depth that formed early in this last storm cycle (Saturday Dec. 19^th) resting on weak snow from early December are the suspected culprits.  As winds died down on Saturday afternoon with the storm, these slabs are masked below 6-18” of soft, surface snow in places.  With a lot of traffic in the backcountry over the last 2 days and good visibility (to view lots of terrain), this doesn’t appear to be a widespread problem; rather it’s pockets of instabilities waiting for a trigger.  With this kind of avalanche problem safe travel practices will again be a key way to manage any uncertainties as we move in to a period of high pressure.  Watching your partners, having an escape route planned, grouping up in safe zones and carry and know how to use your avalanche rescue gear will be paramount for a safe holiday season in the backcountry.

We still lack information from the periphery areas such as the Girdwood Valley, Summit Lake and now Johnson Pass/ Lynx Creek (open to snowmachines today).  Generally these areas have a shallower snowpack than Turnagain pass and can potentially harbor more weak snow.  If you are out and about in these zones today please consider submitting a quick observation or even just a photo or two here.

Close-up look at the crown face of a snowmachine-triggered wind slab avalanche from Sunday.  More details here.

For folks pushing in to steeper terrain today, you can expect to deal with fast moving, low to medium volume loose snow avalanches (sluffing).  As temps drop and the surface becomes more unconsolidated, these will grow in size.  Usually manageable if anticipated, this is an avalanche problem that can knock a skier off their feet in steep, unforgiving terrain but is unlikely to bury a person. 

                               Lots of loose snow sluffing initiated by skiers can be seen in the fading solstice light yesterday on Widow Maker.  

Cornices have grown a fair bit from Saturday’s storm. As we enter a several day stretch of mostly clear weather and folks are traveling further into the backcountry, don’t forget to give these features a wide berth! There are at least a couple of suspected cornice failures yesterday both on the Tincan ridge and the Sunburst ridge, likely from folks simply walking too close to the edge. 

Glide cracks: Really, glide cracks??  We observed a new (in the last few days) glide crack opening up looker left of Widow Maker on the back side of Seattle ridge.  As with cornices, give these features a wide berth as they are akin to the really drunk guy at the holiday party: Unpredictable!

                             Recent glide crack observed on the backside of Seattle ridge in Main bowl.