One more sunny day is on tap (24 seconds more than yesterday) before clouds fill in tomorrow and we wait in anticipation for how the ‘Christmas Storm’ develops. The winds that were forecast yesterday did not produce at Turnagain, leaving the majority of the snowpack capped with 6-12+” of very soft and loose faceting snow. This has made for good riding conditions, but it has also created a ‘base-less’ pack in thin areas and early season hazards such as rocks still remain.
Fresh shallow wind slabs: We are missing data from two of our key wind sensors from last night. Winds may have picked up just enough to form shallow wind slabs/crusts in certain areas. This will be something to look out for today. (The Seattle Ridge sensor is rimed up and the Sunburst station has a battery issue we are working on).
Sluffs: Watch your sluff if heading for the steep terrain. With such weakly bonded snow on the surface, triggering a loose snow avalanche on slopes 40 degrees and steeper is likely. These sluffs could be quick enough and carry enough momentum/volume to be a concern on the longer sustained slopes.
With all the cold weather we have seen in the past 6 weeks, we have developed several weak layers in our thin snowpack. These are composed of two of the ‘classic’ persistent grain types: facets and buried surface hoar. These weak layers are still present, but the ‘slab’ that sits on them has decomposed and become faceted in most places – without a slab, you can’t have a slab avalanche. The exception are steep rocky slopes where old wind slabs, still stiff enough to be a slab, sit unsupported on weak layers. If you venture to these areas, watch for old stiff wind slabs and if one does release and knock you off your feet, where would you go?
Photo: Buried surface hoar found under a thick old wind slab. Pit results showed that with a big force, the layer could fail and propagate; unlikely but not impossible in the very steep zones.
Surface Conditions?? We are set up again with a very weak foundation once the next snowfall hits.
Although cornices are pretty frozen in place, breaking off one of these, or a chunk, is still possible while on ridgelines.
Yesterday’s first day with gaining daylight (11 seconds) was bluebird with light and variable winds. Temperatures were in the single digits in the parking lots at 1,000′ and near 10F on the ridgetops.
Today, we should see sunny skies with winds bumping up slightly from the North and West to the 5-10mph range. Temperatures are forecast to be slightly warmer, in the teens at all elevations.
Looking ahead to the Christmas weekend: A large low pressure is headed our way. Southerly winds should pick up along with high clouds tomorrow morning before the precipitation. The system is bringing warmer air and we could see rain at sea level but snow at 1,000′.
“Strong winds coinciding with moderate to heavy
snowfall could produce blizzard conditions in turnagain Pass and
Portage Valley Sat afternoon through Sat night. There is still
some uncertainty as to the degree of warming that will occur in
Portage Valley. Temps in this area could rise into the mid 30s Sat
evening and produce a fairly wet snow or mix and mitigate the
potential for blowing snow. Turnagain pass should safely stay all
snow through Sat night. That said, issued a blizzard watch for
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||11||0||0||25|
|Summit Lake (1400′)||1||0||0||8|
|Alyeska Mid (1700′)||13||0||0||17|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Sunburst (3812′)||Under repair||Under repair||Under repair||Under repair|
|Seattle Ridge (2400′)||12||Rimed||Rimed||Rimed|
|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|
|04/15/21||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|
|04/10/21||Turnagain||Observation: north sides||lance breeding|
|04/09/21||Turnagain||Observation: Girdwood to Turnagain Road Observations||W Wagner Forecaster|
|04/05/21||Turnagain||Avalanche: Resort bowl Seattle creek head wall||Clint Kyffin|
|04/04/21||Turnagain||Observation: Center Ridge||Andy Moderow|
|04/03/21||Turnagain||Observation: Repeat Offender – Seattle Ridge||Troy Tempel|
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.