Triggering a slab 2’ thick is becoming more difficult and less likely with time. In the last few days snowpack observations have revealed a weak layer of buried facets to be thinner and less reactive. The slab sitting on this weak layer also seems to be settling out and is not as thick and strong as it was a week ago in many places.
With that said propagation potential does still exist and triggering a slab avalanche is possible on slopes steeper than 35°. This problem will be more likely on Southern aspects where a sun crust/facet combo can been found. There is also elevated concern in the 2600-3000’ elevation band where this facet layer is sitting on top of a stout crust.
Triggering a slab will be more likely in these specific places. Avoid thin areas around rocks or steep rollovers on well-connected slopes steeper than 35°. Obvious clues such as collapsing/woomphing may not be present. A larger trigger, such as several people on a slope, may be just enough to initiate a slab in motion. Be sure to practice safe travel habits. Identify safe spots, move between islands of safety one at a time, and always have an escape zone in mind.
In areas such as Girdwood and above 4000’ in Turnagain Pass more uncertainty exists due to lack of information about these zones.
Moderate winds have eroded many ridgetops back to the “anti-tracks” created over two weeks ago making it easier to stay off of the slab in the Alpine.
Today Northeast winds are expected to increase to 20-35 mph this afternoon along ridgetops. Only a trace of new snow is expected this afternoon and there is currently not a lot of snow available for transport. If winds increase as forecasted small pockets of isolated wind slabs, 4-6” are possible on leeward terrain features.
Yesterday a dense valley fog remained along Turnagain Arm, but in Turnagain Pass skies were clear and sunny. Temperatures were in the 20’s F in the morning and reached the high 30’s F in the afternoon along ridgetops. Light winds 5-10mph from the Southwest kept surface snow conditions cool throughout the day.
Temperatures remained warm overnight, in the low 30’s F along ridgetops. Winds were light, averaging 10-20 mph from the East. No new precipitation was recorded in the last 24 hours.
A trace of new snow is expected this afternoon at higher elevations and light rain at sea level. Temperatures will remain warm in the low-mid 30’s F. Ridgetop winds from the North will be in the 20-35mph range. This evening precipitation and winds are expected to increase. Winds could be as high as 45 mph along ridgetops with up to 5 € of snow at higher elevations. Rain/snow line will be around 1000′.
Winds look to be backing off by late evening. Tomorrow more of the same is expected. Warm temps in the 30’s F with rain at sea level and up to a few inches of snow at higer elevations.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||30||0||0||40|
|Summit Lake (1400′)||24||0||0||6|
|Alyeska Mid (1700′)||30||0||0||23|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||28||NW||10||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: 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.