It is the dreaded rain-on-snow that is in our future today, and into the early part of the week. With climbing temperatures overnight and periods of heavy rain expected at sea level, the question is, “How high will the rain get?” The answer is, 1,200′ for sure, likely 1,500′ at times and possibly a bit higher.
Wet loose snow avalanches will be the most likely type of wet avalanche to be triggered. These can entrain significant amounts of heavy dense snow if the slope is sustained and steep enough (> 35 degrees). If you are getting out today, watch for areas where the snow is becoming saturated and heavy. Steering clear of steep saturated slopes will be good ways to avoid a wet sluff. Also, keep in mind terrain traps, such as steep narrow gullies in the Tincan Trees. These steep walled and narrow terrain features can pose a threat if even a small amount of heavy snow slides down onto you.
In the Alpine terrain, above treeline, we are expecting around 6-10″ of wet to moist snow to fall. Along with this, winds are forecast to be strong from the East and Northeast which will quickly form wind slabs, drifts and cornices. The warm nature of the new snow will allow it to bond rather quickly to the preexisting surface, however with the rapid loading expected today, be wary of fresh slabs and drifts. Watching for current wind loading and cracks shooting from your skis/board will be good ways to suss out if slabs are sensitive.
It is time to put glide avalanches back on our radar. With warming temperatures we could see a number of glides cracks open up and release in the next several days. Yesterday, we saw a slab that has moved during the past week and looks ready to avalanche. Staying out from under glide cracks will be key this week.
Glide slab in the Seattle Creek drainage (East facing ~2,000′).
Weather yesterday was relatively mild with overcast skies, light winds from the East and Northeast and only a trace to an inch of snow accumulating above 1,000′ (rain below).
Overnight, temperatures and winds have increased at all elevations as the leading edge of a large and complex low pressure system moves in from the Gulf. We can expect up to an inch of rain to fall throughout the day below 1,500′ with 6-10″ of wet snow above. Winds have already begun to climb and will be blowing from the East in the 35-45mph range. Temperatures are also climbing and should top out around 30 deg. F on the ridgetops and the upper 30’sF at 1,000′ on Turnagain Pass.
For Monday, precipitation intensity will diminish slightly with forecast amounts around .5″ of rain and 3-5″ of snow (rain/snow line ~1,200′). Winds will continue from the East and should diminish slightly as well. Temperatures will remain warm, near 30F on the ridgetops and the upper 30’s at 1,000′. It looks as though it will be Wednesday before temperatures cool back off for snow to make it down near sea level.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||34||1||0.1||20|
|Summit Lake (1400′)||33||0||0||5|
|Alyeska Mid (1700′)||33||1||0.22||17|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||29||NE||18||46|
|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.