Yesterday there were a number of avalanches observed that ran either during the Sunday/Monday storm or yesterday afternoon with the warming and sunshine. Avalanches were observed on Penguin Ridge above Girdwood, in Portage, Skookum, Turnagain Pass and Summit Lake, both slab avalanches and wet loose avalanches.
|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|
Travel in avalanche terrain is not recommended today. Human triggered avalanches are very likely. Large to very large avalanches are expected and could run into flat terrain below. Hopefully the weather forecast is enough to convince you that today is not the day to go to the mountains. Precipitation started around midnight last night and a total of 1-1.5″ of rain is forecast to fall up to 1600′ and possibly higher as temperatures continue rise. Above the rain/snow line this will fall as a foot or more of heavy snow. The winds are easterly 25-40 mph with gusts into the 60s. This comes after a day of warm temperatures, a night without a freeze below 2000′ and on the heels of the last storm that brought 1-2′ of snow to the forecast area. With the storm today our cold snowpack is getting its first real introduction to free water and some rapid loading, a recipe for avalanches. Natural wet loose avalanches and wet slab avalanches are likely today at elevations near and below where the rain/snow line ends up. In addition, storm slabs are expected at upper elevations, enhanced by wind loading and cornice falls are likely as well. Who knows glide avalanches might make an appearance too! There are buried crusts and we have been talking about buried weak layers for months now. The loading today might tip the balance for avalanches stepping down to layers of buried surface hoar and/or facets (persistent weak layers) or a weak interface on a crust and result in an even larger avalanche. This is especially likely in Summit Lake south of Turnagain Pass, where there is an overall thinner snowpack with more advanced weak layers. The travel advice for the day is stay home and avoid roof avalanche hazard!
Yesterday: Skies were partly cloudy with scattered showers. High temperatures in the 40°Fs and winds were easterly 5-10 mph with gusts into the teens. Winds picked up in the evening and increased to 20-30 mph gusting into the 40s. Precipitation started around midnight with 0.3 SWE /1-5″ of snow falling.
Today: Rain and snow that could be heavy at times, 0.8″ SWE and 8-15″ of snow. Rain/snow line is forecast to be around 1600′. High temperatures in the 40°Fs at sea level and high 20°Fs at 3000′. Winds are easterly 25-40 mph with gusts into the 60s. Overnight rain and snow continue 0.3 SWE/ 1-5″ snow, with lows in the high 30°Fs at sea level and 20°Fs in the alpine. Easterly winds remain strong initially and then decrease overnight.
Tomorrow: Cloudy skies and rain and snow showers. High temperatures will be in the 20°Fs in the alpine and 30°Fs and 40°Fs in the mid and lower elevations. Winds will be easterly 5-15 mph with gusts into the 20s.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||34||2||0.5||112|
|Summit Lake (1400′)||36||1||0.3||47|
|Alyeska Mid (1700′)||33||3||0.33||128|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||27||n/a*||n/a*||n/a*|
*The Seattle Ridge wind sensor was rimed yesterday and is hopefully coming online this morning as strong winds set it free.
|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|
|04/22/21||Turnagain||Observation: Turnagain Seattle Ridge / Seattle Creek||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.