Wet slab and wet loose avalanches remain our primary concern once again today. The snowpack is wet, unconsolidated and literally falling apart. Today is our 9th day of unseasonably warm weather and last night was our warmest yet. We hit 54F at Portage, 40F at 2,400′ on Seattle Ridge and 37F at 3,800′ on Sunburst to name a few.
We did see large natural avalanche activity yesterday and I suspect it continued during the overnight hours with the spike in temperature. Most of yesterday’s activity was in the form of wet slab or wet loose at elevations below 3,500′. The one exception was a large deep slab with a start zone near 6,000′ that is suspected to be more of a dry slab avalanche. The rundown of yesterday’s larger avalanche activity:
Photo below is of Raggedtop – sent in by Andy Dietrick, Alyeska Snow Safety program
Natural activity from yesterday on Seattle Ridge
The warm temperatures and rain on snow for over a week have combined to destabilize the snowpack. Yesterday was the first clear day with no added precipitation, but the warm conditions combined with the sun and wind seemed to tip the balance. Today the clouds and rain are back but the very warm temperatures will continue to destabilize the pack.
Avalanche conditions aside, travel conditions are difficult. The snowpack is isothermal and unsupportable with a variable and breakable surface crust.
At upper elevations (roughly above 3,500′) where snow has been falling for the past nine days we have a deep slab avalanche problem. We have received around 6-10′ of new snow which has overloaded the weak snow near the ground in many areas. The clear skies yesterday allowed for a good look at all the large avalanche activity from the past week. Check out these observations HERE and HERE for some of the older activity.
We did have one deep slab release yesterday on Goat Mtn (mentioned above and pictured below).
Cornices have grown substantially during the past two weeks. With these warm temperatures cornices are likely to start falling and could easily trigger a large avalanche below.
Yesterday’s sunny and warm weather made it feel like springtime in January. Temperatures reached the mid 50’s F at sea level and the mid to upper 30’s F on the ridgetops. There was a spike in temperature during the overnight hours. Winds continued from the East with averages in the 30-40mph range.
Today we will see clouds move in as another pulse of moisture approaches from the South. Rain below 4000′ should start falling this morning with up to .2″ accumulating through the day (2″ of snow above 4,000′). Temperatures should remain warm – mid 50’sF at sea level and mid 30’s to 40F on ridgetops. Winds continue to be strong from the East averaging ~50mph with gusts up to 80 or more.
The long term forecast is showing signs that this warm, wet weather will move out mid-week with clear, slightly cooler weather moving in.
|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.