Rain falling on snow has initiated a widespread avalanche cycle in the mid elevation band. The Girdwood Valley saw 2.4″ of rain in the past 24 hours below ~2,200′ and subsequently significant wet slab and wet loose avalanche activity. Wet avalanches were reported up to 2,700′ in elevation, which is just above the rain/snow line and where very wet snow is falling. This trend is expected to continue today. There is not much known about the activity yet at Turnagain Pass where around 2″ of rain fell or at Summit Lake with 1″ of rain, but we can expect wet avalanche activity in these areas as well. The rain/snow line has been fluctuating between 2,200′ and 2,500′ in general. Yes, this is soaking the meager snowpack between 1,000′ and 2,500′ and allowing the alders to bounce back up.
Image: A look at Tincan Ridge at Turnagain Pass being wetted down up to the top of the trees. Once these storm cycles cease, the upper elevations should look much different, the lower will hopefully remain snow covered!
In the Alpine, wet and heavy snow is falling, which becomes drier with elevation. From our rainfall totals at the snow stations, we can expect that during the past 24 hours 1-2+’ of snow has accumulated. Cornices are building and the weak pre-existing snowpack continues to be loaded. Storm snow avalanches that include storm slabs, wind slabs and cornice breaks all can be expected today at the high elevations. What can also be expected is the snow may stick fairly well and instead of avalanche immediately as a storm snow problem, it may overload and tip the balance of the weak snow sitting near the ground and create a very large avalanche, taking most of the snowpack with it.
Again, the message is simple for today, avoid avalanche terrain. This means steering clear of slopes 30 degrees and steeper with nothing steeper above or near you. Also, be extra cautious of evaluating runout zones.
Heavy rain and overcast skies filled the region yesterday. Rain/snow line looks to have been between 2,200' and 2,500' depending on location. Around 2-2.5" of rain fell while 1-2+ feet of heavy wet snow fell at the upper elevations. Much less precipitation fell inland on the Kenai (Summit Lake area). Winds have been strong from the East, averaging 20's-30's mph with gusts in the 70's. Temperatures are way too warm - low to mid 40's at sea level and up to 32F along the 3,000' ridgelines.
For today, Monday, we can expect this very warm system to move out and precipitation rates diminish. Around .3" of rain is expected today below 2,900' and 1-3" of heavy snow above. Temperatures should remain very warm, in the mid 40's at sea level and 32F along the ridgelines. Winds from East and Southeast will remain moderate to strong, in the 20's - 30's mph with much stronger gusts. Slightly cooler temperatures are expected tonight along with .5-.6" of rain below 2,100' and 3-6" of snow above as another system moves in.
For Tuesday and heading into the week, the active warm and stormy weather pattern with continue with the next storm moving in tonight. However, "by the end of the work week there is high confidence for the anticipated pattern change" says the NWS, meaning a return to cooler temperatures and a break from the incessant stormy weather.
*Center Ridge and Summit Lake SNOTEL stations stopped reporting at 9pm and 11pm respectively. Values below are estimates.
**Reported 24-hour water at the RWIS station at Turnagain Pass (1000' elev.) and RWIS Summit Lake (1300' elev.)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880')||*35||0 (rain)||**1.9||*25|
|Summit Lake (1400')||*35||0 (rain)||**1||*10|
|Alyeska Mid (1700')||35||0 (rain)||2.4||15|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400')||31||SE||28||65|
|05/18/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/30/21||Turnagain||Observation: Sunburst||W Wagner Forecaster|
|04/27/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/26/21||Turnagain||Observation: Magnum||Creighton/ Hoople|
|04/25/21||Turnagain||Observation: Sunburst||Nick D'Alessio|
|04/24/21||Turnagain||Observation: Airplane obs||Johnston-Bloom / DiJulia /Hilliard Forecaster|
|04/24/21||Turnagain||Observation: Corn biscuit||Heather Johnson|
|04/23/21||Turnagain||Avalanche: Lynx Ck Drainage||W Wagner Forecaster|
|04/23/21||Turnagain||Avalanche: Sunburst||Eeva Latosuo|
|04/23/21||Turnagain||Observation: Center Ridge Turnagain pass||Joe Kurtak|
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.