There were likely small avalanches last night associated with the new snow. Otherwise, the last known avalanches were small natural wind slabs from 11 days ago.
|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|
After a welcome overnight snowfall, to sea level, the northwest outflow winds should waste no time in moving the new snow around, especially in the higher elevations. For snowfall totals, as of 6am this morning, up to a foot has fallen in the upper Girdwood Valley and 6-8″ at Turnagain Pass and Summit Lake. Avalanche concerns will be directly related to the amount of new snow and windloading today.
In general, the new snow is not likely to bond very quickly with the old surfaces; from faceted loose snow to harder old wind blown snow. The new snow is light and in areas with only 6″ the avalanche conditions will be less than areas seeing up to a foot. The key for today will be to 1) watch for how much new snow has fallen and 2) look for active windloading that is creating fresh wind slabs.
Wind Slabs: Any slope with wind loading today will be worth avoiding. Wind slabs could be anywhere from 1-2′ thick and should be easy to trigger. The outflow winds funnel in all directions at Turnagain Pass, so our best bet is to simply watch where the wind is transporting snow, feel for stiffer snow over softer snow, and note any cracks that shoot out from us.
Storm Slabs: In sheltered areas with up to 10″ of new snow or more, soft slab avalanches breaking at the new/old snow interface are possible. The new snow may be too light to create a slab without wind effect, but this is something to look for in areas with up to a foot of new snow.
Loose Snow Avalanches – Sluffs: Triggering a sluff should be fairly easy on the steeper slopes. There will likely be evidence of natural sluffs from overnight seen today.
Quick hand pits to check the amount of new snow, any stiffening from the winds, and looking for easy failures at the new/old interface will good ways to assess today’s issues. The good news is the problems are at the top of the snowpack, making them much easier to identify.
Snowpack structure at 2,600′ on the backside of Seattle Ridge yesterday, 12.6.22. Roughly 6-8″ of new light snow sits on top of this pit as of this morning.
Yesterday: Cloudy skies and light snowfall (to sea level) was over the region. Overnight precipitation increased and this morning Girdwood Valley has received 10-12″, while Turnagain Pass and Summit Lake saw 6-8″. Ridgetop winds were easterly, 10-15mph, until last night when they shifted to be light from the northwest.
Today: A few light snow flurries could add another 1-2″ of snow this morning before tapering off midday. Skies should also begin to clear midday. The northwest ridgetop winds are forecast to blow in the 20-30mph range with gusts in the 40’s. Temperatures look to remain in the 20’sF at the mid elevations and the teens in the Alpine.
Tomorrow: Mostly sunny skies are expected tomorrow. The strong NW winds look to remain through tomorrow. For Friday and Saturday, mostly clear skies are forecast with light NW winds.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||30||5||0.5||28|
|Summit Lake (1400′)||29||4||0.5||20|
|Alyeska Mid (1700′)||30||10||0.9||30|
|Bear Valley (132′)||33||8||0.75||N/A|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||25||SE||8||18|
|02/08/23||Turnagain||Observation: Eddie’s||Megan Guinn & John Sykes|
|02/07/23||Turnagain||Observation: Seattle Ridge||Wagner / Keeler Forecaster|
|02/07/23||Turnagain||Avalanche: Pete’s North||Megan Guinn|
|02/06/23||Other Regions||Observation: Johnson Pass to Bench Lake||Justin Siemens|
|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|
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.