The GOOD NEWS: A quick hitting snow event rolled through last night and has, so far, added 10″ of new snow at Turnagain Pass. Girdwood Valley has seen slightly less with 8″ overnight and Summit Lake much less, only 2-3″. When adding last night’s total to yesterday’s 2-4″, we have a 24-hour accumulation of 10-14″. This is “low density” new snow which is great news, but that leads us to the 2nd part of the story…
The BAD NEWS: This new snow has fallen on a VERY weak surface with a hard bed surface below (see photo). Although it’s only a foot of new snow, it will simply have a hard time sticking to the old sugary snow below. Adding to this, avalanches triggered could run far with the help of the hard bed surface underneath. In short, this is classic case for creating very touchy avalanche conditions. This means you are more likely than not to trigger an avalanche if you enter slopes over 35 degrees. The exception are slopes where the new snow is so unconsolidated that it is not forming a slab – in this case, large sluffs can be expected.
Things to watch for if you are headed out:
Photo below is from yesterday of the ‘weak’ faceted snow that sits on top of a hard bed surface. Imagine a cohesive slab of snow 12″ thick sitting on top of this weak layer/bed surface combination – yep, that’s what we have this morning and it’s a problem…
Yesterday’s light snowfall added 2-3″ before intensity increased overnight adding another 10″ at mid elevations. (Check out the Turnagain Pass Snow Stake by clicking this link!). Winds have been Easterly and moderate with Sunburst averaging in the 20’s mph overnight and Seattle in the teens. Temperatures have decreases slightly with the snowfall as well and are sitting in the mid-20’s F this morning on ridgetops.
Today we can expect snowfall to decrease and skies start to break. Winds should remain from the East in the 15-20mph range and temperatures in the mid 20’s F at the mid and upper elevations.
Looking to Friday night and weekend, a potent storm system is slated to arrive that could bring “incredible snow rates” to Turnagain Arm and Anchorage – see this NWS discussion HERE.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||28||10||1||34|
|Summit Lake (1400′)||29||2||0.2||13|
|Alyeska Mid (1700′)||30||8||0.8||23|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||27||SE||10||22|
|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.