Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Wednesday, November 23rd 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 MODERATE on steep slopes for wind slab and soft slab avalanches. Recent snow and wind has formed mostly shallow slabs sitting on a slick pre-existing surface. These are possible to be triggered by a person today. Additionally, sluffing will be easy to initiate on steeper slopes, running fast and far. Lower elevation areas, below 2500′, receiving less than 6” of new snow have a generally LOW danger. Lastly, limited exposure to glide cracks is still in effect.
We got a bit of a refresher yesterday. Just under a foot of new medium density snow fell in the upper elevations with around 6-7 inches at 1500′. Moderate winds have moved the snow around just enough to form soft wind drifts and slabs. Though the amount of new snow is modest, on many slopes it fell on a hard slick layer.
Yesterday the snow was not bonding to the old firm surface very well, and I believe today will be similar. Most of these slabs will be shallow and not pack too big of a punch. However, they can entrain additional snow and run fast and far, filling up gullies/benches and pushing you around or somewhere you don’t want to go. Watch for cracking in the new snow from your skis or board over rollovers and off ridgelines. This is a sign a wind slab or soft slab is prime to be triggered, most likely from your feet. Also, keep an eye out for sluffing in steeper terrain as these can also entrain more snow than expected.
The glide avalanche problem continues to deserve mention. Avoid spending time under, or next to, glide cracks and old glide avalanches. This may mean adjusting your route slightly or where you decide to eat lunch.
Around 6-11″ of snow fell yesterday in our region. Girdwood Valley picked up slightly more than Turnagain Pass and Summit Lake a bit less than Turnagain. Temperatures were in the low teens in most locations and winds were in the teens from the east, except Sunburst which reported NNE gusts into the 30’s. As the storm weakens today, expect scattered snow showers, with a possible trace of accumulation, and partly cloudy skies. Winds look to be gusting up to 20mph from the NW and temperatures hovering around 10F.
CNFAIC Weather Page and the NWS forecast
Currently all motorized areas in the CNF Glacier and Seward district remain closed. Turnagain Pass is close to having adequate snow cover to open and we will be evaluating this more extensively today and tomorrow so stay tuned.
Tonight Kevin will be talking about Terrain and Route Finding at our third, in a series of five, free Fireside Chats. Join him at 7pm at the Girdwood Ranger Station! More details are on our training and calendar page.
I will issue the next advisory Thursday, November 24th, 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 754-236. Thanks and have a great day.