Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Sunday, January 8th 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).
20 Mile drainage is open to motorized use! Park at the Portage rail depot and cross the RR tracks at the designated spot ONLY. Please follow bamboo poles from the parking area.
We have a CONSIDERABLE danger today for wind slab avalanches in areas above treeline that are expected to receive moderate, and possibly strong, winds. Slopes with recent wind deposited snow are likely to be sensitive to the weight of a person and human triggered avalanches are likely. Storm snow sluffing and soft slabs avalanches will be likely in steep terrain as well. There is a generally MODERATE danger for storm snow sluffing and small soft slabs near and below treeline in wind sheltered areas.
AnCNFAIC Staff storm day in the Chugach and Kenai yesterday has put down around 8-10″ of very light fluffy snow in most areas and added to our great start to the year. Low visibility kept people and observations near and below treeline however.
The primary concern is for wind slab avalanches that are contingent upon the increase in northwest winds today. There is ample low density snow available for the winds to transport and form soft sensitive slabs. Secondary concerns are storm snow sluffing and soft slabs formed within the new snow. If the skies break up enough for travel above treeline, careful evaluation of the surface conditions are prudent.
There is roughly 12-18″, possibly more, of storm snow from Thursday (1/5) that is sitting on recycled powder from the late December and early January cold spell. The new snow has shown signs of good bonding to this older snow surface but observations are limited to near and below treeline and how the snow is reacting above treeline should still be suspect. Expect any avalanche that gets moving to be fast and far running, as this is common with light snow.
A reminder that there are more weak layers present in the Summit Lake area. The most recent one is made up of near surface facets that formed during the cold spell. This layer sits right under the new snow and associated wind slabs from Thursday and has shown signs of being quite reactive.
Snow fell fairly steadily yesterday and has tapered off overnight. Most locations picked up around 8-10″ of very low density fluff in the past 24 hours. Temperatures remained warm at the upper elevations, ~20F, and have begun to drop this morning while mid and lower elevations hovered near 10F. Winds picked up yesterday from the east and blew around 15mph with gusts in the mid 20’s and have decreased overnight.
Today, intermittent snow showers could add an inch to some locations but should continue to taper off while skies may break up enough to allow for better visibility. Winds have shifted to the northwest and unfortunately are forecast to increase to the 40mph range, possibly stronger. These winds are ushering in cold air so expect temperatures to drop back into the single digit realm.
CNFAIC Weather Page and the NWS forecast
I will issue the next advisory Monday 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.