Northwest winds15-20mph are expected in the upper elevations today. With up to a foot of snow available for transport this could easily form shallow wind slabs around leeward features in the upper elevations. A Northwest flow can sometimes cause varying wind directions for Turnagain Pass and its common to see a more Southwest direction in some places. Watch out for hard over soft snow, wind pillows or drifts and be on the look out for obvious signs like cracking and whumpfing sounds. Its also possible that a windslab could step down into an older weak layer within the snowpack. More on this below.
There is plenty of snow available for transport on all aspects. Pay attention as surface conditions change with building winds. Depending on the wind direction this Northern aspect of Magnum could see cross loading today.
The snowpack right now has a variety of weak layers within the top 3’ of the snowpack. A widespread layer of weak faceted snow up to 2′ deep is our primary layer of concern and was the culprit in many skier triggered avalanches over the weekend. Two seperate layers of buried surface hoar also exist within the top meter of the snowpack in some places in the alpine, but they haven’t been found everywhere. With that said these layers have presented propagation potential in some test pits this week. Should you see active wind loading today, your extra weight could be enough to tip the balance on a steep unsupported slope. Pay attention for stiff snow over weaker snow and avoid wind loaded slopes where the potential of triggering a dangerous slab avalanche is still possible with our current snowpack set-up.
Should you go into avalanche terrain be aware of other groups and practice safe travel rituals. Only expose one person at a time, always have an escape zone, and regroup in safe spots.
Digging a quick hand pit and poking your ski pole into the snow are good ways to evaluate the snow as you move. Be cautious around steep slopes if you find hollow snow or stiffer snow ontop of loose snow below. This photo was taken yesterday of very weak faceted snow at 2000′.
Expect cornices to be sensitive and easy to break off. They also could trigger a slab avalanche below. If you choose to walk a ridgeline today, give these a wide berth and be aware of people below you.
“Sluff” may also be fast moving on steep protected terrain features where the snow is loose and unconsolidated. Be aware of terrain features that could have high consequences if knocked off your feet.
Yesterday a temperature inversion was the cause of valley fog and cooler air near sea level (single digits F) and warmer air in alpine (low 20F’s.) Skies were partly cloudy, winds were calm and no new precipitation was recorded.
Today Northwest winds are expected to increase this morning to a sustained15-20mph. Temperatures will range from 15-25F today. Skies should be partly cloudy and no precipitation is expected.
Northwest winds should become light early tomorrow morning with a possibility of flurries in the morning. Temperatures are expected to be in the low teens (F) in the alpine and single digits near sea level.
*** Alyeska Midway weather station only had data available from 6am to 10pm on Dec.21st, and Sunburst weather station only had data available from 12pm-7pm on Dec.21st.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||21||0||0||27|
|Summit Lake (1400′)||13||0||0||9|
|Alyeska Mid (1700′)||***23||***0||***0||***16|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||13||ESE||1||4|
|05/06/20||Turnagain||Avalanche: Pastoral Peak, north face||Andy Duenow|
|04/10/20||Turnagain||Avalanche: Wolverine||Mike Records|
|04/10/20||Turnagain||Observation: Eddies lookers right shoulder||Matt Yoder|
|04/09/20||Turnagain||Observation: Bench Peak||Mike Records|
|04/04/20||Turnagain||Observation: Pete’s North||Anonymous|
|03/26/20||Turnagain||Avalanche: Tincan – Proper (SW facing)||CNFAIC Staff|
|03/26/20||Turnagain||Avalanche: Seattle Ridge||W Wagner Forecaster|
|03/25/20||Turnagain||Avalanche: Sunburst Uptrack @ 2000′||J. Boisvert|
|03/24/20||Turnagain||Observation: Turnagain – Road Observations||W Wagner 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: firstname.lastname@example.org
|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.