Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Thursday, January 12th 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 remains CONSIDERABLE today for storm snow instabilities with a new round of snow and wind over our area. Fresh sensitive wind slabs and drifts, storm snow sluffs and older lingering wind slabs from Tuesday will all be concerns today. Human triggered avalanches are likely and expert level skills in terrain management and snowpack evaluation will be required for backcountry travel today.
An eventful past few days of weather, avalanches and road closures kept nearly all but a few folks out of the Turnagain Pass backcountry recently. Not only do we have just one observation from yesterday, our only working wind sensor in Turnagain Pass, on the Friends of CNFAIC Sunburst weather station, has been blown apart for the second time this season. Therefore, there are some big question marks heading into today, especially above treeline.
What we do know is winds redistributed snow to large degrees Tuesday and have formed deep rounded wind pillows and slabs. These looked to be in most exposed locations including midway down slopes and cross loaded around sub-ridges. Today, this winded surface will be covered up with, what looks like, 8-14 inches of new snow with moderate southeast winds.
Fresh wind slabs and storm snow loose avalanches will be our primary concern. The wind is forecast to be in the 40mph range which will have an easy time forming touchy and easily triggered avalanches on wind loaded slopes. Additionally, there is a possibility of triggering an older, and potentially large, wind slab from Tuesday.
The rime crust that was formed on the night of 1/7 is still prevalent in the Tincan area and likely so in the majority of Turnagain Pass. This crust is something we are watching and will be good to keep in mind and look for.
For anyone traveling in the backcountry today, expert level travel skills are required and careful snowpack evaluation necessary. The changes the snowpack has undergone the past several days, along with our limited information from the field, warrants conservative decision making.
We had a day of reprieve yesterday from strong winds and snow from Tuesday. However, skies remained cloudy and temperatures warm, in the mid 30’s at sea level and the mid 20’s F on the ridge tops. Overnight, the SE winds picked up and are blowing in the 20’s with gusts just above 40mph. Around 4-6 inches of snow has fallen at Turnagain Pass and similar amounts in the Summit area with Girdwood Valley a bit less.
Today snowfall will continue and could be heavy at times with moderate southeast winds. Accumulations today are expected to be around 5-8 inches, this is on top of the 4-6 inches from overnight. Temperatures have begun to drop to the mid to low 20’s at most locations (regardless of elevation) and has brought the rain/snow line back to sea level.
Kevin will issue the next advisory Friday 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.