Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Sunday, December 11th 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).
Don’t miss Wednesday nights big double premiere and CNFAIC benefit!! “The Continuum” along with “One For the Road” will be playing at the Sitzmark Bar & Grill – Alyeska Resort. More details are on our training and calendar page. Also, the string band Midnight Sun Zombies, will be playing. Come on out and show your support!
The avalanche danger is CONSIDERABLE for wind slab avalanches on all wind drifted slopes due to strong wind and new snow overnight and throughout today. Naturally occurring wind slab avalanches are possible and human triggered avalanches are likely. Expert level route finding and terrain management skills will be necessary for backcountry travel today.
A pulse of new snow and strong wind overnight has increased the avalanche danger. Around 6-8” of snow has fallen above 2000′ in the Girdwood Valley, Turnagain Pass and Summit Lake areas. The snow has come in with sustained northeasterly winds around 35-40mph, gusting to 70mph. Snowfall and wind have tapered off this morning, but are forecast to intensity again throughout the day.
Wind slab avalanches are the primary concern. Fresh deposits of wind drifted snow will be sensitive and likely easily triggered by a person. Watch for unusual loading patterns from the strong winds at all elevations. This includes, wind slabs building mid-slope and around subtle terrain features. The slabs formed overnight and today should vary in depth and strength, from deep and soft to hard and supportable. Deep wind slabs and slabs that are supportable have the best chance of breaking above you and taking you for a ride.
If there are any areas that have escaped wind damage, watch for soft slab avalanches. The new snow has fallen with increasing temperatures causing an “upside down” layering. This set up will enhance the instability in the new storm snow.
Yesterday afternoon, skies became cloudy and winds picked up ahead of a storm system impacting our area today and into Monday. Overnight, winds blew on the ridge tops from the NE at 40mph with gusts into the 70’s. Snowfall, adding up to 6-8” above 3000′ and 2-3” at 1800′, accompanied the wind. Temperatures have risen 2-5 deg. F at most stations and are currently around 30F at 1800′ and in the mid 20’s at 3000′.
Snowfall intensity has decreased this morning but will increase again throughout the day. Expect anCNFAIC Staff 8-10” above 2000′, with around a foot in favored locations. The NE winds have also decreased this morning but are forecast to pick up again, gusting to 60+mph. Temperatures should remain steady.
CNFAIC Weather Page and the NWS forecast
I will issue the next advisory tomorrow 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.