Turnagain Pass

The last known human-triggered avalanche reported was a small wind slab pocket on Tincan, on Friday (12/1).  Beyond that, we’ve seen evidence of a natural avalanche cycle that ramped up as last week’s storm was winding down on 11/30.  Crowns were reported from Main bowl and Warm up bowl on the moto side of the highway to Sunburst and upper Bertha Creek on the non moto side.

It was a pretty quiet weather day yesterday with light winds, cooling temps and no real precipitation to speak of.  Given that lack of weather input, we dropped the danger rating in the treeline elevation band to LOW danger today.  Low danger does not mean no danger and isolated areas below treeline still have the potential to nurture wind loaded pockets.  However, the most likely places to find unstable snow will be in the alpine, above ~2.500’ where winds have redistributed last week’s fresh snow into shallow wind slabs.  Below ridge lines , steep gullies or convexities where a slope  begins to roll over into steeper (greater than 30 degree) terrain should all be seen as suspect and have potential to harbor wind slabs in the 1-2’ range.

This is a ’normal caution’ regime and while not an overly dangerous avalanche problem, keep in mind that skiing/ riding above terrain traps (trees, cliffs, gullies, creeks, etc.) amplifies the consequences should a slope slide.  Keep eyes on your partners, communicate intentions and as always, be rescue ready. 

Currently, the Summit Lake zone has a similar snowpack set up as the Turnagain area.  Click on the video below for an update from new Chugach Avalanche forecaster Daniel Krueger who’ll be keeping tabs on, and issuing a weekend avalanche outlook for this area and points south on the Seward Ranger District this winter. 

‘In this world there’s two types of crusts my friend.  Those that prove problematic, and those that go dormant.’ — Quote adapted from The Good, the Bad and the Ugly

The Good: We’ve seen literally thousands of tracks on all aspects and elevations from skiers and snowmachiners testing the Thanksgiving crust since it was buried last week, with minimal avalanche activity.  Snowpit tests results have been mixed but overall are showing the late November storm has bonded well to this crust.    

The Bad: Crusts are notorious for ‘waking up’ down the road as the snow weakens and facets out above and below these layers.  Buried crusts can often support a significant load before avalanching, or may just become dormant with time.  Click here for some ‘Ruminations on Rain Crusts’ from our neighbors to the East.

The Ugly:  This crust is quite widespread throughout the advisory area and has been found in all snowpits (up to 3,400’ and likely higher) over the past week.  As such, if this layer becomes reactive it has potential to be a region wide problem, extending across multiple different zones and through elevation bands. 

The Thanksgiving crust interface isn’t our greatest concern today, but it’s an obvious marker within our snowpack and one we’ll be keeping tabs on in the days and weeks ahead. 

The snowpack in Summit Lake area and Turnagain Pass is quite similar right now with the Thanksgiving crust buried in the mid-pack and quite easy to suss out, even with a quick hand pit.