Turnagain Pass Avalanche Forecast

Another round of snow is expected today, Christmas Eve- and this time, should hit most of Southcentral. Light snowfall should begin late morning in the Girdwood/Turnagain Pass area. Between 2-4″ is forecast to accumulate by the evening with 3-6″ falling in the higher terrain. Easterly ridgetop winds are slated to pick up into the teens and possibly up to 25mph. These are perfect wind slab development speeds in areas the winds are transporting snow.

Image from our all-star weather forecasters at the National Weather Service!

The primary avalanche concern will be wind slab avalanches. These are expected to be touchy as they are not likely to bond well to the surface underneath. Remember the clear weather last weekend? This old snow surface, blanked in surface hoar and pictured below, is now buried under Sunday’s snow and will become buried a bit more with today’s snow. What to watch for if headed out:

• How much snow has fallen since the weekend?
• Have the winds moved the snow around and loaded the slope you intend to ride?
• If skies break for a moment, are there any recent avalanches?
• Is the snow stiffer over softer snow? Does it crack or collapse under you?

These are all signs the new snow is unstable and could avalanche on slopes steep enough to slide. Due to the smaller amounts of new snow, slabs should be on the smaller side- 4-12″ thick. The size of a potential avalanche is completely dependent upon the new snow amounts and size of the terrain, or slope in question. Quick hand pits are also good ways to test if the recent layer of snow is bonding to the old surface.

Storm slabs:  In the treeline band and areas out of the wind with over 6″ of new snow since the weekend, shallow soft slabs may be found.

Sluffs:  With the new low density snow, triggering sluffs on steep slopes should be fairly easy.

Solstice Surface Hoar photos: Left, Allen Dahl and right, Troy Tempel. 

Glide cracks are likely obscured and difficult to see with the poor visibility and light snow covering cracks. They are still there however, hanging out under rocky cliffs and rolling slopes. There are two in the Tincan Trees we know of and many in the Corn Biscuit and Magnum area. As always, limit/avoid time under these as they can release spontaneously at any time.

Glide cracks in the Gold Pan region of Turnagain Pass. This area is in the upper north zone of Bertha Creek, behind the Corn Biscuit/Magnum ridges. Thank you to Eric Parsons for the photo!

In the high Alpine, above 3,000′, we have been tracking a weak layer of snow sitting near the base of the snowpack.  This weak layer is buried anywhere from 1-6+ feet deep due to the variable wind loading during the December storm cycles. There has been a lingering concern a person could trigger a large avalanche if they hit the wrong spot. Data is pointing to this layer being dormant as this point. However, we will keep it on the radar especially in areas where the overall snowpack is shallower – towards the southern end of Turnagain Pass, in Summit Lake and in the Crow Pass terrain north of Girdwood.