|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|
Today is a proper storm day, with intense snowfall and strong winds through the daylight hours. As of early Thursday morning we have already received 6 to 12″ of new snow (0.5 to 1.0″ of SWE) and winds have picked up to the mid-thirties on Sunburst with gusts up to 70 mph. Snowfall intensity and wind speeds are forecast to peak around noon today, with an additional 12″ of snow accumulation and sustained strong winds. Natural avalanches 2-5′ deep are likely and human triggered avalanches are very likely. Due to the amount of new snow avalanches can be triggered in sheltered areas in addition to wind loaded areas. It is pretty simple today, avalanche conditions are very dangerous so avoid avalanche terrain and be aware of overhead hazards because natural avalanches are likely and could runout to valley bottoms.
The snow line should be between 400-800′ today with wet snow falling up to 1200′. The southern flow direction of this storm system is likely to drop more snow in Girdwood, Portage, and Placer than Turnagain Pass. Several weak layers exist in the upper snowpack which could produce large avalanches with the added new snow load. These include a layer of low density new snow that fell early in the storm on Sunday (see video here) and a layer of buried facets on top of the New Years crust. Both these layers have shown signs of instability in recent tests (see ob here). Regardless of the exact weak layer, the snowpack is likely to be overloaded today with the rapid addition of new snow and strong winds.
Example of existing weak layers in the upper snowpack. In this location there is potential for failure on either a weak layer within the storm snow from Sunday/Monday or on a deeper layer of buried facets above the New Years crust. Photo 1.12.22
Yesterday: Light to moderate snow showers and clouds in and out throughout the day. Snow accumulations of 6-12″ (0.5 – 1.0″ SWE) as of this morning. Winds were moderate in the mid teens to twenties with gusts into the mid thirties. Temperatures hovered just below freezing at 1800′ and in the twenties at ridgetops.
Today: Today should be a full on storm day, with heavy snowfall and strong winds peaking during daylight hours. Accumulations of around a foot of snow today with potential for higher amounts in Girdwood, Portage, and Placer. Winds will be out of the east in the 40 mph range with gusts ranging from 60-90 mph. Snow level should be 400-800 ft with wet snow up to 1200 ft.
Tomorrow: The storm will shift to a more southerly flow on Friday, which means some areas will see continued and potentially increased snowfall intensity and other areas will see minimal additional accumulation. Currently, weather models are showing minimal additional snowfall in Turnagain Pass on Friday. However, in Girdwood, Portage, and Placer snowfall looks to continue throughout the day on Friday. The snow line elevation could rise a bit during the day as temperatures increase slightly. Stay tuned for updates as the system develops.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||31||6*||0.6||75*|
|Summit Lake (1400′)||26||1||0.1||26|
|Alyeska Mid (1700′)||31||8||0.7||NA|
* Estimates due to snow depth sensor errors
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||25||SE||16||35|
|02/07/23||Turnagain||Observation: Seattle Ridge||Wagner / Keeler Forecaster|
|02/07/23||Turnagain||Avalanche: Pete’s North||Megan Guinn|
|02/05/23||Turnagain||Observation: Rookie Hill||Tony Naciuk|
|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|
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.