Turnagain Pass

One last cloudy and rainy day before skies finally clear and let the sun in. Today marks the 18th, and hopefully last, day of this impressive warm March storm series. Despite few folks in the backcountry and limited visibility yesterday, we know of six natural wet avalanches that occurred at Turnagain Pass. One was a wet slab just under Tincan’s CFR ridge, photo below. Another was a glide avalanche on SW facing Eddies Ridge and four were seen/heard by an Alaska Avalanche School Level 1 course. Of these four, three were seen on North facing Sunburst Ridge and one on SE facing Seattle Ridge. During the past 24-hours, close to an inch of rain fell in Girdwood Valley, 2.8″ in Portage Valley and almost half an inch at Turnagain Pass. Today, only .25″ is forecast yet avalanche conditions are expected to remain similar as even light rain on snow up to 2,000′ will keep the pack unstable.

A few things to consider for backcountry travel:

• Know, and avoid, avalanche terrain. Give runout zones an extra wide berth. These wet avalanches can do wild things and run where we may not expect them to.
• Glide cracks are opening and some are releasing. Limit/avoid being under cracks. New cracks have been seen in the Tincan Trees – photo below.
• Cornice falls. Cornices are huge and have been growing and falling for two weeks now. Beware once skies clear!
• Upper elevation storm snow problems. The higher in elevation the drier the snow – wind slabs, sluffs and storm slabs are all a concern. Direct sunlight this week could trigger large slabs in the Alpine. Heads up.
• Shallow snowpack zones such as Summit Lake harbor many old weak layers (facets and buried surface hoar). Over the past few days numerous large wet slab and dry slab avalanches have released. These zones are just as dangerous, if not more, right now.

Looking ahead: Sunshine and very warm temperatures (even in the upper elevations) are in the forecast beginning Monday for the week. Avalanche danger may stay more elevated than one might expect. It is true once the snowpack begins to freeze it will lock up and limit avalanche activity. HOWEVER, the pack is incredibly wet and it will take more than one clear night to stabilize it for the morning hours. Of course, sunshine and warm ambient temperatures will quickly destabilize the snowpack again during the day/evening hours. Hence, springtime avalanche issues will be in full effect next week! Keep in mind upper elevations could produce some very large avalanches cornice falls during this warm and sunny period. The mountains do weird things in the spring and we need to be extra cautious with route selection, where we eat lunch, avoiding steep southerly slopes late in the day, and on. 

Wet slab avalanche releasing yesterday (Mar 23rd) off of Tincan’s CFR ridgeline, Westerly aspect at 2,000′. *Note the opening glide cracks in the trees lower on the slope. 

Wet slabs and wet loose avalanches wreack havoc on Seattle Ridge. Many steeper slopes has avalanched and many are hanging in the balance. 

Thanks to Alex McLain for snapping this photo of a wet slab on the shoulder of Moose Mtn in the Summit Lake area (near the Hope Y). The avalanche occurred sometime between 11am and 1pm yesterday, Mar 23rd.