Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Wednesday, March 7th 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).
Most areas this morning will have a LOW avalanche danger. Our primary concern is up above treeline, where pockets of MODERATE hazard exist in wind slabs and wet and dry sluffs. Watch for changes this afternoon as the sun melts South facing slopes and causes small wet loose natural avalanches.
Overall stability seems to be good. The snowpack continues the trend this season of no persistent weak layers. The exception is recent shallow wind slabs in steep terrain. Over the weekend we heard of a number of people popping small wind slabs. New snow on Monday night with moderate wind contributed to that problem. It’s the kind of problem that won’t likely be found except in steep terrain where the wind has loaded pockets in just the right way. We have found a fair bit of pockety shallow wind slab with loose soft snow underneath, the kind of snow that feels stiff and suspect.
Dry sluffs on shady aspects and wet sluffs on sunny aspects will be possible today. Neither of these are likely to cause big problems unless the terrain exposure is dangerous by itself. Yesterday we saw quite a few wet loose avalanches in the afternoon. Most of these were on direct South facing steep chutes, like the ones just above the Seward Highway between Bird and Portage. A couple of these actually popped shallow slabs as the wet snow entrained drier snow on the way down. South facing slopes are probably going to be the worst quality this morning until the sun has time to soften the melt/freeze crust.
Yesterday morning had 6-8 inches of light density dry snow in our region. Some of that snow fell with a moderate East wind before it got calm at the tail end of the snowfall event. Through the daylight hours yesterday, a sunny and calm day persisted. All the sun produced melting on the South aspects, resulting in occasional sun sluffs and a crust layer.
Sunny and calm weather is expected again today. Colder temperatures this morning should rise substantially when the sun gets high enough to produce heat. A second day of sun will likely cause more sun induced sluffs, but perhaps fewer than yesterday.
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.