The strong easterly winds that accompanied the Christmas storm have died down slightly overnight but will be on the rise through the day today as another system is headed our way this evening. We have little information for above treeline and areas receiving wind due to low visibility and dangerous avalanche conditions but we can expect a good natural avalanche cycle occurred during the past 36 hours and will ramp up again this evening and into tomorrow with additional snow and wind.
With the significant round of snowfall in the past two days, we have given our early season weak snowpack a good shock to the system. It was no surprise to see widespread avalanche activity yesterday. All the new snow has bonded well to itself but the problem is it is sitting on varying layers of weak faceted snow that will keep it from bonding to the mountain sides. This means avalanches are failing below the new snow making them 3-4′ deep and deeper in windloaded areas – slabs this thick are unmanageable. Observations from below treeline yesterday give a sense of this problem. As the new snow settles with the warming temperatures today the pack will shift from mostly unconsolidated new snow to a denser slab which will add to the already unstable situation. It is great to see so much new snow (a more than doubling of the pack) but patience will be the key to staying safe in the backcountry.
It has been an extra white Christmas for the Eastern Turnagain Arm with between 3 and 4 feet of snow falling since the morning of the 24th. Yesterday, Turnagain Pass saw an additional foot of accumulation with storm totals around the area listed below. As this system exits to the north this morning another one is right on its heels and will usher in warmer wet conditions for this afternoon through Thursday evening. Snowfall amounts look to be in the 10-16″ range.
Total snow accumulation beginning early morning on the 24th:
Girdwood Valley €“ ~45 € snow with 4.5 € of water equivalent
Turnagain Pass €“ ~35 € snow with 3.4 € of water equivalent
Summit lake €“ ~8 € snow with 0.8 € water equivalent
Snow densities have averaged around 10% region wide, this next storm is warmer and should put down higher density snow along with rain or a rain/snow mix at sea level. Winds have died down overnight (E at 20mph gusting 40mph) but are forecast to increase again through the day (E in the 50-60mph range) with the rapid approach of the next system. Temperatures will rise a couple degrees today to the mid 20’s F at the ridgetops and low 30’s at sea level.
This is 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).
Graham will issue the next advisory Thursday morning December 27th.
|04/19/21||Turnagain||Avalanche: Triangle, Seattle creek||Will Morrison|
|04/18/21||Turnagain||Avalanche: Turnagain Pass Road Obs||Andy Moderow|
|04/18/21||Turnagain||Observation: Seattle Ridge, approximately 300 yards south of the up track||Brent Byrne|
|04/17/21||Turnagain||Avalanche: Road obs||Johnston-Bloom / Moderow Forecaster|
|04/16/21||Turnagain||Avalanche: Seattle Ridge||Wendy Wagner Forecaster|
|04/16/21||Turnagain||Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge||CNFAIC Staff Forecaster|
|04/16/21||Turnagain||Observation: Sunburst||Lance breeding|
|04/15/21||Turnagain||Observation: Tincan||Schauer/ Rothman Forecaster|
|04/13/21||Turnagain||Observation: Turnagain Pass Road Obs||A Schauer Forecaster|
|04/12/21||Turnagain||Observation: Tincan||Johnston-Bloom / Latosuo Forecaster|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: email@example.com
|Area||Status||Weather & Riding Conditions|
This is 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.