Turnagain Pass

Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Friday, December 16th at 7am. This will serve as a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

Thanks to everyone who joined the benefit showing of Teton Gravity Research films at the Sitzmark on Wednesday. Thanks to Wild Alpine for organizing. Your support makes these forecasts possible.

BOTTOM LINE

The avalanche danger is moderate for new storm snow. The snow that fell yesterday combined with wind was causing isolated small natural avalanches on South faces. Depending on wind and precipitation, this trend could continue today. Watch for stiffer wind slabs above tree line that could break under a skier or rider.

AVALANCHE DISCUSSION

The front that moved across yesterday dropped a short but sweet amount of snow around Turnagain arm. Areas of Girdwood got more than a foot of snow, Turnagain Pass got a solid 8-10 inches. By mid afternoon yesterday the skies cleared and the wind diminished.

The primary concern today will be the most recent snowfall breaking in wind loaded areas. We could see some natural avalanche activity yesterday, breaking in shallow wind deposited pillows on South faces. The wind direction in Turnagain pass was mostly Northeast, blowing the snow onto South and West aspects. Watch for local variations in the wind direction.

This new snow fell onto a lighter density and colder surface. Initial bonding between the layers was poor, but it should get better quickly over time. Today is a perfect day to practice quick hand pits to test that interface between the most recent storm snow and the older snow from Sunday. Isolate a 1 foot by 1 foot column 1-2 feet deep with your ski pole and pull downward with your hand to gauge the strength and shear quality at the interface (no need to get your shovel out). You should be able to do a dozen of these tests as you ascend with only a couple minutes total time lost. Also consider ski cutting short, low consequence test slopes on your way down to see if they break into slabs.

The new snow came in with temperatures in the low to mid 20s at 3000 feet. Expect to find fairly light density snow except where the wind stiffened it into cohesive slabs. Sea level temperatures were above freezing, so snow density will increase as you descend.

MOUNTAIN WEATHER

Yesterday’s snowfall already lost several inches due to settlement.

The weather patterns right now are fairly complex. 2-4 inches of snow is forecasted for today. Expect moderate Southeast wind up to 40mph tonight. Snow showers will be the trend heading into the weekend. Check our weather links page for a more comprehensive analysis of current weather patterns.

CNFAIC Weather Page and the NWS forecast

I will issue the next advisory Saturday morning at 7am. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.