Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Wednesday, February 29th 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 LOW with pockets of MODERATE this morning. Be aware of likely sluffing in steep terrain. Most areas with slope angles less than 35 degrees will have a LOW avalanche danger.
Our most recent storm that ended Monday morning refreshed the surface conditions nicely, and seems to be stabilizing quickly. With good visibility yesterday we were able to get a more comprehensive survey of the natural avalanche cycle. A few larger slab avalanches were seen in the region, but generally the mountains held together. The more typical problems associated with the last few days continue to be loose snow sluffing in steep terrain and large cornice failures. In a handful of places the sluffs and cornices were able to pull slabs underneath.
The snowpack continues to have only minor near-surface problems. The storm on Sunday/Monday fell on top of well developed stellar crystals that have a similar (but less persistent) weak layer effect as buried surface hoar. The worst case scenario today is finding an area of stiffer (~1 foot deep) wind slab on top of those loose stellars where it might have the ability to propagate into a larger slab. Based on what we saw yesterday this is not likely, but could be possible on very steep wind loaded terrain. Our test pits yesterday showed moderate but clean failure on this layer, with no propagation in an extended column test.
The more likely avalanche problem today will be in the form of loose point releases. Check out Wendy’s observation from yesterday. The top 4 inches of surface snow is very loose, and will fall away easily on steep terrain in a sluff avalanche. The volume and mass from these was small to medium in size, and manageable if expected.
Yesterday was a mostly sunny and calm day in the mountains. There has been no additional snow accumulation in 48 hours. Some afternoon sun exposure produced minor surface melting on direct South aspects.
Snow is possible for the rest of the week, but the pattern is generally weak for precipitation. Today’s forecast calls for 2-4 inches of snow with minimal wind. Unless snow accumulations are greater than the prediction, today’s weather should not affect avalanche conditions very much.
CNFAIC Weather Page and the NWS forecast
Wendy will issue the next advisory Thursday 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.