Turnagain Pass

This morning, skies are clear, winds are light from the east and temperatures cold. This morning also marks the 16th day of the January drought. During this dry spell, winds have been generally northwesterly and impacting ridgelines and peaks north of Girdwood, through Turnagain Arm and Portage Valley and south of Johnson Pass. The heart of Turnagain Pass has been spared much of the wind. Although there are various weak layers in the snowpack that were causing grief earlier, the slab on top of them is being slowly eaten away (faceting) and triggering an avalanche in one of these old buried layers is unlikely. What is more of a concern is finding a wind slab that was formed over the past week or so that is sitting on weak faceted snow. With the variable wind effect in the region, don’t let the green danger rating keep you from being observant and sticking with your safe travel practices. Until a change in weather arrives, we are in a Normal Caution avalanche regime, meaning there are still issues to watch for listed below.

Some wind effect in the higher terrain on the southern end of Seattle Ridge at Turnagain Pass. 1/15/20.

Wind slabs on weak snow:  If you are headed to the steeper and higher elevation terrain, be on the lookout for wind affected snow. Watch for pillowed snow surfaces, feel for hollow feeling snow and generally speaking- stiffer snow over softer snow. Cracks that shoot out from you are a red flag as well as whumpfing (collapsing) of the snowpack. Even a small wind slab can be dangerous if it knocks a person off their feet and down a rocky slope.

Loose snow sluffs:  The surface snow is so loose and faceted it is very easy to initiate a sluff in steep terrain. These sluffs have been catching a few folks off guard. They can be quite heavy and gain more volume than one might expect. If heading to steep chutes or slopes, sluffs should not be underestimated.

Glide cracks:  Despite the frigid temperatures, glide cracks continue to ooze open. It’s always a good idea to limit any exposure under them as they can release at any time.

Cornices:  We have had no reports of cornice failure for some time, but we still need to give them a wide berth.

Glide cracks on the northern most portion of Tincan, just above Todd’s Bowl. 1.17.20. Photo: Allen Dahl

Snowpack update:  This graph shows the snow depth from the past 30 days at 1,880′ at the Turnagain Pass SNOTEL. After around 2 feet of snow fell during the holidays, for a total snow depth of 46 inches, the depth has decreased (settled) almost a foot over the past 16 days and now sits at 36 inches. Note: there was a short pulse of moisture on Jan 13th that did add 1 inch of snow during the dry period. Also of note, the snowpack is just under half of what it normally is this time of year.