|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
March has slipped by already, Easter Sunday is here along with April Fools’ Day and sunset tonight will be around 8:45pm. For anyone that has been out in the mountains lately, the snowpack is getting more and more tired; like a runner in the final mile of a marathon. Almost three weeks have passed since the last snow event. A refresh is needed, will it come? Possibly later this week, we’ll have to wait and see. What about springtime corn skiing? Sunshine has been strong but air temperatures have not been warm enough during the day to let it soften Southerly surface crusts. Slightly warmer temperatures today could help this.
There has been no weather for over a week that has contributed to avalanche danger and the snowpack continues to stabilize. The chances for triggering a deep slab avalanche are becoming more unlikely as the days go by. However, if you’ve been tuning in, you’ll know we have a very poor structure to the pack. Various weak layers sit 2-4′ below the surface and are composed of facets and buried surface hoar. There has been no known avalanche activity for 10 days and stability tests show high strength in the snowpack despite the poor structure. This all said, the mountains by nature are uncertain and our snowpack does have weak layers. There is the remote possibility someone could find just the wrong spot on just the wrong slope and trigger a large and destructive slab avalanche. This scenario doesn’t fit neatly into the danger scale as it is a low probability, high consequence situation.
What to keep in mind:
– Periphery zones such as Girdwood Valley and the South end of Turnagain Pass towards Johnson Pass, Lynx Creek and Summit Lake all have thinner snowpacks and therefore are more suspect for finding an outlier slab avalanche
– Northern to Eastern aspects have a generally thinner snowpack
– Trigger points are often in thin areas of the snowpack near rocks or in scoured areas along ridges
– As always, practice safe travel habits and minimize exposure in avalanche terrain
Be aware of warming later in the day on Southerly slopes, especially steep southerly slopes with rocks that will help heat up the snow around them, aiding in possible wet avalanche activity. As we gear up for a warmer day today, keep the afternoon warming on your radar!
Deep Persistent Slab is challenging to fit into the danger scale when stability is increasing due to their potential size and already low probability of triggering.
Suncrust is having a difficult time softening on Southerly aspects. This particular crust was found around 2,500′ by Allen Dahl on Corn Biscuit.
Watch out for cornices along ridgelines. It’s that time of year where cornices will begin to slowly warm during daytime heating, making them easier to break off. As always, give cornices plenty of space and limit exposure underneath them.
These are great days to be exploring. Thanks to Troy Tempel for the photo below from the far side of the Seattle Ridge drainage on Saturday. This is looking East back at Seattle Ridge proper and Zero, -1 and -2 bowls from the Western side of Seattle Creek. Note the large cornices in the distance along Seattle Ridge.
Sunny skies with thin high clouds were over the region yesterday. Ridgetop winds were light from the West (5-10mph) on the higher peaks. Temperatures were near 35F at 1,000′ and 25F along ridgelines. Temperatures have dropped to the teens in valley bottoms overnight but have remained warmer (mid 20’sF) at the upper elevations due to a warmer air mass that moved in. Note the increase overnight from teens to 21F at 4,200′at the Penguin weather station.
Today, sunny skies and warmer temperatures are on tap. Ridgetop winds look to increase to the 10-20mph range and shift more Northerly during the day. Temperatures should warm to the mid 30’sF in valley bottoms and remain in the mid 20’sF along ridgelines. Colder air looks to stream back in from the North this evening at the higher elevations, dropping temperatures back to the teens.
For tomorrow and Tuesday, mostly sunny skies, cool temperatures and windy off-shore conditions are expected. A chance for clouds and snow flurries may occur mid to late week as models show a low pressure developing in the Bering. Stay tuned.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||27||0||0||76|
|Summit Lake (1400′)||22||0||0||30|
|Alyeska Mid (1700′)||26||0||0||71|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||23||Variable||4||15|
|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: 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.