Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Saturday, March 31st 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 of the region will have a MODERATE danger rating for multiple problems on most aspects and elevations. Touchy buried surface hoar can be found in the drier snow at higher elevations. Anything receiving lots of sun exposure recently will have buried sun crusts and possibly wet avalanche problems late in the day.
We got several more reports and photos sent in yesterday from recent human triggered avalanches. Most of those happened on Thursday, soon after the snowfall from Wednesday. All the information is indicating buried surface hoar on colder shadier aspects and sun crusts/wet slides on sunnier aspects. Nothing we’ve seen has been very deep or large, but the problems are widespread through the region in terms of location, aspect, and elevation.
Concern #1 – Buried Surface Hoar
Buried surface hoar was apparently quite reactive on Thursday. We got a great report of snowmachine triggered slides in Seattle creek with pictures. AnCNFAIC Staff slide off the West shoulder of Tincan appeared to be skier triggered but was not reported to us. Buried surface hoar is the most likely weakness to be found in drier snow.
Concern #2 – Buried Sun Crust
Southern facing slopes that have been getting a lot of sun recently will have multiple layers of sun crusts, both buried and on the surface. Some recent avalanches have been triggered on these layers. It’s not a good idea to spend time on South faces, especially late in the day.
Concern #3 – Wet loose and wet slab
Spring meltdown starting hitting hard last Sunday and hasn’t let up since. South faces are falling apart pretty quickly, especially at low elevations. Even East and West facing slopes can have wet avalanche problems late in the day.
It’s been several days since any significant snowfall. Temperatures have consistently been reaching into the low 40s during the day and barely freezing at night. Crust is forming on the surface in most areas at night.
A weak low pressure system is spinning in the Gulf of Alaska and affecting Southcentral. Rain and snow showers are predicted for today with little accumulation. Warm Spring temperatures will continue to melt the surface up to fairly high elevations.
CNFAIC Weather Page and the NWS forecast
Wendy will issue the next advisory Sunday 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.