Yesterday’s storm turned out to be a Girdwood Special with storm totals above treeline between 1-2’ while Turnagain Pass picked up only half that, 6-12” depending on elevation. A hand full of natural avalanches were seen and reported despite low visibility. These were above treeline and mostly garden variety wind slabs in the small to medium category. Seattle Ridge’s cross-loaded gullies on the east face flushed out small slabs and sluffs but debris stopped before hitting the lower angle runnout zones. Below treeline no avalanche activity was seen as the new snow was quite warm and sticky. Even though Summit Lake only squeaked out a few inches that area was still able to produce natural avalanches thanks to the strong NE winds.
Today, the strong east wind is on the decline but still blowing moderate which is enough to build slabs. Watch for these to be fairly touchy and just beginning the mending process. They most likely will be 1-2+ feet in depth and found off ridgelines, rollovers and cross-loaded in gullies and sub-ridges. If you see cracking in the snow around you it will be a bull’s eye clue that slab is unstable. With the potential for lifting clouds and travel in the upper elevations, remember even a small avalanche triggered can be dangerous if one gets washed into a terrain trap (i.e., over a cliff or into a gully).
Below treeline: There is between 5-10″ of medium to dense powder on top of multiple crust layers. Yesterday the powder was sticking quite well to the crust, but if the dense snow becomes saturated today with rising temperatures and a creeping up of the rain/snow line, wet loose and wet slab avalanches will be possible above the crust.
Deep slab: We are continuing to track the weak snow near the ground. This is buried 4-8’+ deep, gaining strength and not likely to be triggered by a person in many areas in the Turnagain Pass and Girdwood Valley. But that said, shallow areas remain in these regions and Summit Lake, being shallower in general, harbors more of a concern. There are a couple great observations demonstrating these locations HERE and HERE.
With over 24 hours of warm temperatures, snow and strong east wind cornices continue to grow. A few of these broke off yesterday triggering shallow wind slabs below. Keeping an eye for what is above you and giving these guys a wide berth will be prudent as they could be close to the tipping point.
Obscured skies, snow and strong wind that dominated Saturday has persisted overnight. Sunburst weather station at 3,800′ recorded hourly averages in the 40’s and 50’s mph from the east with gusts in the 90’s. Storm totals (with a rain/snow line ~300′) from the past 36 hours, ending this morning at 6AM are:
Turnagain Pass (1880′) 6″ snow – 0.6″ water eq.
Alyeska Mid (1700′) 18″ snow – 1.3″ water eq.
Alyeska Top (2800′) 18-24″ snow – 2.2″ water eq.
Summit Lake (1400′) 2-3″ snow – 0.2″ water eq.
Today the strong east ridgetop winds will back down significantly to the 20-30mph range and shift to a more south and southwesterly direction. Snowfall should linger off and on adding around 1-3 additional inches. Temperatures are mild, 32 at 1000′ and 23 at 3800′, and should decrease slightly through the day.
Tomorrow we have a break in clouds and precipitation. Temperatures should cool off and skies clear. Could be a very nice day before another system looks to push clouds and flurries our way Tuesday/Wednesday.
Fitz will issue the next advisory tomorrow morning, February 11th.
|05/06/20||Turnagain||Avalanche: Pastoral Peak, north face||Andy Duenow|
|04/10/20||Turnagain||Avalanche: Wolverine||Mike Records|
|04/10/20||Turnagain||Observation: Eddies lookers right shoulder||Matt Yoder|
|04/09/20||Turnagain||Observation: Bench Peak||Mike Records|
|04/04/20||Turnagain||Observation: Pete’s North||Anonymous|
|03/26/20||Turnagain||Avalanche: Tincan – Proper (SW facing)||CNFAIC Staff|
|03/26/20||Turnagain||Avalanche: Seattle Ridge||W Wagner Forecaster|
|03/25/20||Turnagain||Avalanche: Sunburst Uptrack @ 2000′||J. Boisvert|
|03/24/20||Turnagain||Observation: Turnagain – Road Observations||W Wagner 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.