Turnagain Pass

Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Saturday, March 3rd 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).

BOTTOM LINE

The avalanche danger has dropped to MODERATE on steep terrain above treeline. Watch for stiffer wind slabs with poor bonding to the dry powder underneath. South aspects may have a buried sun crust layer that could create a more dangerous weak layer/sliding layer combination. I’m less concerned below treeline today, where wind effect is less pronounced and slopes tend to be less steep.

AVALANCHE DISCUSSION

Light wind and only small amounts of snow during the last several days have brought the avalanche potential down. We only have a couple of shallow depth problems to worry about, but there is some avalanche potential to keep us on our toes.

Primary concern – Wind slab from Thursday that built on top of weaker, low-density powder. Pit tests have been showing moderate to poor strength on this layer. The concern over this problem is diminishing over time, but it remains a possibility that deserves some attention. The area where this could be an issue will be above treeline where the wind was blowing into the 40s on Thursday, on the lee West aspect and cross-loaded North and South aspects. It will probably require steeper slope angles to bust loose and propagate. You can expect most of the stiffer slab to have 6-10 inches of powder snow on top of it.

Secondary concern – Lightly sun crusted South faces. We’ve had a few reports that take note of the sun crust. There is enough solar energy to melt direct South facing slopes, and the problem will get worse quickly if we get a truly sunny day in the near future. When this got buried Wednesday, a few places were showing poor bonding between the crust and the new snow on top. This problem, topped with light density snow and a stiffer slab on the surface could equal a surprising combination.

Loose snow is prevalent today. We have noticed a fair number of natural point releases in the light density surface snow. In steeper terrain this could become a problem if not managed correctly.

Outside of these issues, the snow quality should be quite good this weekend. We found colder powder extending down to sea level yesterday. It’s a good time to explore some lower elevation areas that typically don’t get good backcountry travel conditions.

MOUNTAIN WEATHER

We got anCNFAIC Staff 2-4 inches of light density snow yesterday that fell with almost no wind. Temperatures remain well below freezing in the forecast zone, the only exception being stronger solar exposure during the peak of midday sun.

Cloudy skies have been predominant over the last several days, but periods of better visibility have been found. Today will continue that trend. A couple more inches of snow are possible, but I’m guessing that sunny breaks in the clouds could happen.

CNFAIC Weather Page and the NWS forecast

Wendy will issue the next advisory Sunday morning. 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.