Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Friday, March 2nd 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).
The avalanche danger is trending towards MODERATE, but pockets of CONSIDERABLE may be found on steep wind loaded slopes above treeline. Watch for stiffer wind slabs with poor bonding to the dry powder underneath. Areas below treeline and at lower slope angles will have a MODERATE danger today.
We don’t have a lot of information to go on this morning. Yesterday’s weather was mostly shrouding the higher elevations in clouds as it snowed most of the day. We do know that snow was building, and the wind was blowing. Conditions were ripe for building wind slabs on top of a low density layer of powder (our surface snow from Monday and Tuesday).
We got a great observation from the Girdwood valley
describing poor bonding between the building wind slab and the snow underneath. It seems likely that steep wind loaded slopes above treeline could be triggered by people today. With diminished snowfall and wind this morning, expect a slowly decreasing possibility for this to happen.
Wind slabs and surface sluffs are the primary concerns in the backcountry today. Wind was from the East, so expect to find more snow and deeper slabs on West, South, and North aspects. The unstable layers are still confined to the recent storm snow, and deeper avalanches will be unlikely to trigger.
One detail to keep in mind is the formation of sun crusts on South aspects a few days ago. The crust formation was very specific to aspect, elevation, and slope angle but it could be the area where surprises may be found. Wendy found it on a South face, between 2000-3000 feet on a moderately steep slope. Crusts like this can be the slippery layers that allow wider propagation and larger avalanches.
AnCNFAIC Staff weak storm system is still affecting our region today. Snowfall since yesterday morning ranged from 3-8 inches. Wind during the peak of snowfall reached into the mid 40s yesterday, but backed off last night.
For today, more snow is in the forecast. 2-3 inches is predicted with a light East wind and temperatures in the high 20s.
CNFAIC Weather Page and the NWS forecast
I will issue the next advisory Saturday 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.