|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|
CHANGING WEATHER AND INCREASING AVALANCHE DANGER
A warm, wet and windy storm is over the region currently. Roughly 10 to 12″ of snow has fallen in the Alpine zones with another 10 to 14″ expected today (above 2,500′). At the mid-elevations, roughly 6 to 10″ of wet snow has fallen with an additional 1″ of rain (yes rain) expected up to 2,200′ this afternoon. Easterly ridgetop winds will continue to be in the 20’s with gusts in the 50’s mph.
Although there was bare ground before this storm up to 2,000′, above this a shallow snowpack has been forming (see photos below). Rain last weekend followed by cool temperatures formed a crust up to the ridgetops on this pre-existing snow surface. The kicker is, surface hoar formed on the crust before it was buried yesterday. So, what we have is a perfect recipe for avalanche activity in the upper elevations. Any new snow accumulation is expected to slide off the old snow surface easily. How much avalanche activity we will have and how big those avalanches will be is directly related to how much snow falls. As of this morning, there is roughly a foot of snow from yesterday and another foot expected today – again, this is all above 2,500′. Therefore, storm slabs up to 2′ thick are possible and where winds have been loading up to 3 to 4+’ thick.
Snow falling along the road and up to ~2,200′ is expected to turn to rain by this afternoon. This will saturate and melt much of the 6 to 10″ of wet snow existing in these mid-elevations (1,000′ to 2,500′). The worry at these elevations is being in the runout zone of an avalanche from above where debris can run. All this said, today is a day to leave the mountains alone and look ahead to the cooler weather on tap for the middle part of the week!
Sunburst, above the alders – hard snow with suspected surface hoar on top existed before this storm rolled in yesterday (Saturday)
The pre-existing snow line was a little lower on Tincan, just above1500′
East facing slopes of Repeat Offender on Seattle Ridge on Friday, November 23. Snowline was around 2000′.
Looking into Lynx Creek drainage, Northern aspects before the storm on Friday.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||31||9||1||13|
|Summit Lake (1400′)||31||1||0.2||1|
|Alyeska Mid (1700′)||31||4||0.5||4|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||30||E||11||33|
|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.