|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|
Thumbs up for snow and thumbs down for wind. Human triggered wind slabs, 2-3′ deep, will be likely in steep wind-loaded terrain, especially on unsupported slopes and in cross-loaded gullies. Yesterday’s storm brought about a foot of snow (1″of SWE) to the forecast area with periods of snow falling around an inch per hour. After the mostly dry month of February it really felt like a welcome return to winter. With the snowfall the winds were easterly 10-20 mph with gusts into the 30s. They were definitely strong enough to blow snow around and form wind slabs as observers noted. Last night the winds shifted to the northwest and are forecast to blow 15-30 mph with gusts into the 40s today. As we have mentioned before, this wind flow direction is tricky for Turnagain Pass. It can funnel through the Pass from the south and load north aspects on the non-motorized side, while at the same time load the SE face of Seattle Ridge. It can also split around the Pass and not affect much of the terrain in the heart of Turnagain at all. This wind pattern also increases through channeled terrain and can be more pronounced in Crow Pass and Portage. Because of the flip flop in wind direction there may be wind slab on all aspects. Remember, expect any wind slab you find to be sitting on weak faceted snow and/or surface hoar and that they may be triggered remotely. The wind slabs may also be on a somewhat of spectrum from really stiff and easy to identify in the Alpine to softer slabs that are just slightly more cohesive than the weak layer below at lower elevations.
What to look for if you’re headed out today:
Storm slabs: Yesterday below approximately 1400′, the snow that fell was upside down with heavier/wetter snow on top of drier colder snow and you may find some storm slabs in areas out of the wind. However, the cold temperatures overnight may have helped this situation.
Persistent slabs: There is also a chance that a wind slab avalanche triggered near the surface overloads the older weak layers in the snowpack and steps down creating a larger avalanche. This is another reason for extra caution today.
Sluffs: Steep slopes that are sheltered from the wind have a foot of new soft snow and a few inches of loose facets from before the storm. It will be easy to trigger dry loose avalanches (sluffs) in this terrain.
Click HERE for video.
Yesterday: Skies were obscured and snow fell throughout the day with 6-10″ of accumulation. Winds were easterly 10-20 mph with gusts into the 30s. Temperatures were in the mid 20°Fs to mid 30°Fs. Around 8 pm the precipitation shut off and the winds shifted to the west/northwest 10-15 mph gusting into the 20s. Overnight temperatures dropped to single digits in the Alpine and to the low 20°Fs near sea level.
Today: Skies will be cloudy and there is a chance of light snow showers. Winds will be from the northwest 15-35 mph with gusts into the 40s. Ridgetop temperatures will be in the single digits and it will be in the teens to low 20°Fs near sea level. Overnight northwest winds will ease a little and skies will become partly cloudy. Temperatures will be in the single digits to few degrees below 0°F.
Tomorrow: Skies will become mostly clear. Northwest winds continue, 5-15 mph with gusts into the 20s. Temperatures will be in the single digits to high teens. The weekend looks to be mostly sunny with clouds building in the late afternoon on Sunday as the next weather system approaches.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||25||9||0.7||118|
|Summit Lake (1400′)||23||1||0.1||46|
|Alyeska Mid (1700′)||23||10||0.7||121|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||20||ESE-NW*||9||28|
*Winds shifted from the east to the northwest around 8 pm last night.
|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|
|04/10/21||Turnagain||Observation: north sides||lance breeding|
|04/09/21||Turnagain||Observation: Girdwood to Turnagain Road Observations||W Wagner Forecaster|
|04/05/21||Turnagain||Avalanche: Resort bowl Seattle creek head wall||Clint Kyffin|
|04/04/21||Turnagain||Observation: Center Ridge||Andy Moderow|
|04/03/21||Turnagain||Observation: Repeat Offender – Seattle Ridge||Troy Tempel|
|04/02/21||Turnagain||Observation: Seattle Ridge||Wagner / Schauer Forecaster|
|04/01/21||Turnagain||Observation: Pete’s||Schauer/ Cullen 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.