Today we will see the brunt of the third storm to impact the area since March 27th. Winds are currently gale force from the East along ridgetops and .75-1″ of rain has fallen overnight up to 1,000′. For snow, this equates to the higher elevations accumulating between 1-2+ feet; the mountain landscape will have a much different look when skies finally clear. Another spike in natural avalanche activity is expected today and paths that have already released may be reloading and release again. Storm snow avalanches may also step down into weak older layers in the pack, creating an even larger slide. Add warm temperatures and rain to the mix and there is no question, avalanche terrain should be avoided.
How much load is on the old weak surface from March? Storm totals (March 27 – 6am April 4th):
Turnagain Pass: 3.0″ of H2O, 42+” of snow at upper elevations
Girdwood Valley: 4.2″ of H2O, 50+” of snow at upper elevations
Summit Lake: 1.1″ of H2O, 12-15″ of snow at upper elevations
Large amounts of debris are running to valley bottoms during this storm cycle. Thank you to Turner Pahl for sending in this photo from the north side of the Skookum Valley (just below the toe of the Skookum Glacier). We are unsure of when this specific avalanche released but the photo was taken yesterday.
Again, if choosing to brave the roads and parking lots and play in the flats, please remeber to stay well away from slopes and runout zones – debris can run further than you think during storms like this!
The rain/snow line has climbed from near sea level yesterday to 1,000′ overnight, possibly up to 1,500′ in places. Although we already saw a widespread natural wet slab cycle at 1,500′ on April 1st, we could see another one again today as another round of rain on snow is expected at the lower elevations. Hopefully the visibility will be good enough to see some of the action happening, but as is often the case, much goes unseen.
Snow pit at 2,000′ at Turnagain Pass on Sunburst, April 2nd. Note the wet layers up to 2,000′, they only become wetter at the lower elevations where we are expecting wet avalanches.
Prior to this storm cycle the snowpack consisted of many weak layers of facets and buried surface hoar. As mentioned above, avalanches releasing in the storm snow have the potential to ‘step down’ into old layers where snowpack tests are still showing propagation potential. Today’s strong winds and precipitation are likely to tip in the balance in the upper elevations and we could see an avalanche breaking in the mid-pack or near the ground, with crown depths over 6′ and running the entire length of a slide path.
Obscured skies filled the region yesterday with light flurries and rain to 100′ before the main portion of the storm moved in late in the day. Most of the action is from overnight when ridgetop winds picked up to the 40’s and 50’s mph with gusts in the 80’s from the East. Over 1″ of rain fell to 1,000′ at Turnagain Pass with .75 in the Girdwood Valley. This equates to 1-2+’ of snow at the upper elevations over the past 24-hours. Temperatures have been warm and fluctuating – sea level upper 30’sF, 2,000′ the lower 30’s F, ridgetops in the mid 20’sF.
Today, we should see continued precipitation with .6″ of rain below 1,000′ and 6-10″ of snow above 1,500′. Tonight another .25 of water is expected. The rain/snow line is tough to forecast and it could drop to 500′ and even lower if colder air slides in. Ridgetop winds will remain strong in the 30’s and up to 40mph from the East with higher gusts. Temperatures should remain warm, up to 40F at sea level, in the 30’s at the middle elevations and 20’s F along ridgelines.
This storm looks to stall out and churn through tomorrow and into Thursday bringing continued, but lighter, precipitation and strong Easterly winds.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||35||12||1.1||89|
|Summit Lake (1400′)||34||2||0.3||30|
|Alyeska Mid (1700′)||33||1||0.75||75|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||26||sensor rimed||sensor rimed||sensor rimed|
|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.