|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
A low pressure system will start impacting the forecast area this afternoon bringing moderate to heavy snowfall and increasing winds. The snowfall totals for this storm have come down a bit since yesterday but we still expect a significant new load with 18-24″ of new snow over a 24 hour period starting on Sunday afternoon. The timing of the new snowfall and winds will be the driving factor for how quickly the avalanche danger increases throughout the day. There is uncertainty in the weather forecast, but our best estimate is that significant snow accumulation will not happen until after daylight hours on Sunday.
The main concern for today are wind slabs up to a foot deep that formed yesterday and will continue to form today as we get additional snowfall and strong winds this afternoon. These fresh wind slabs will be possible for a person to trigger and could run farther than normal due to the New Years ice crust being buried just beneath the surface. With limited visibility today it could be hard to see if slopes above you are being actively wind loaded, so be aware of your position in the terrain relative to overhead hazards. Look for signs of recent snow transport on the surface, shooting cracks, and pillows of freshly loaded snow on leeward aspects to identify wind slabs.
Storm Slab Avalanches – As the new snow starts to accumulate this evening and overnight we will see a greater potential for storm slab avalanches at the interface between the new snow and the old snow surface. These could happen sooner if the timing of the snowfall is off, so be aware that if significant snowfall piles up throughout the day the avalanche danger will be rising quickly. We expect the new snow will not bond well to the 3-5″ of faceted snow and buried surface hoar that is on top of the New Years crust.
Yesterday: Overcast skies with light snowfall throughout the day in some areas and just brief periods of snow in other areas, accumulation up to 2″. Winds were moderate to strong at higher elevations with gusts into the upper thirties on Sunburst. Temperatures stayed well below freezing throughout the day, in the teens at lower elevations and single digits at upper elevations.
Today: A low pressure system will start to impact the area early this afternoon with moderate to heavy snowfall. Snow totals are on the order of 3-6″ before midnight on Sunday with another 3-6″ overnight on Monday. Total precipitation amounts could vary substantially across the forecast area with this storm, with higher snowfall totals in portage and placer. Temperatures should rise this evening with the snow line moving up to about 500-700′ overnight. Strong winds will accompany the snowfall with averages in the 5-25 range and gusts into the 50s possible overnight tonight.
Tomorrow: The snowfall should continue tomorrow with snow level rising throughout the day up to around 1000′ tomorrow evening. Total storm snowfall is estimated at 18-24″ by tomorrow evening. Winds will remain elevated tomorrow at 5-25 mph with gusts into the 40s and 50s. Additional smaller pulses of snowfall look to impact the area throughout the rest of this week.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||15||2||0.2||65|
|Summit Lake (1400′)||6||0.5||0.1||22|
|Alyeska Mid (1700′)||14||0||0.02||38|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||10||E||7||22|
|01/31/23||Turnagain||Observation: Johnson Pass area||Megan Guinn / W Wagner Forecaster|
|01/29/23||Turnagain||Observation: Tincan Backdoor||AAS-Level 1 1/27-1/30|
|01/28/23||Turnagain||Observation: Sunburst||Brooke Edwards|
|01/28/23||Turnagain||Avalanche: Seattle Ridge||W Wagner|
|01/28/23||Turnagain||Observation: Tincan Common||Tony Naciuk|
|01/27/23||Turnagain||Observation: Sunburst||John Sykes|
|01/27/23||Turnagain||Avalanche: Lynx Creek||Megan Guinn / W Wagner|
|01/25/23||Turnagain||Observation: Cornbiscuit||John Sykes Forecaster|
|01/22/23||Turnagain||Avalanche: Tincan||Schauer/ Guinn|
|01/21/23||Turnagain||Avalanche: Seattle Ridge||Elias Holt|
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.