Spring has arrived and so has the sunshine. Yesterday was the first warm sunny Saturday of the year. We had reports of relatively small wet loose avalanches on Southerly aspects and one small dry slab on a Northerly aspect (pictured below).
Triggering a dry slab avalanche remains a concern on shady aspects. These Northerly slopes have between 8″ to 2′ of soft settled powder from last week’s snowfall. This snow fell on a variable old surface sporting everything from hard snow, facets and crusts. Bonding between the new and old snow was initially poor, but has improved over the past couple days. That said, we are still finding facets in areas under the storm snow and finding and triggering a slab avalanche remains possible. One of these was found yesterday on Tincan mentioned above. Getting your shovel out and quick hand pits are ways to help assess if the storm snow is sticking or not where you happen to be. Obvious signs on instability such as shooting cracks and whumpfing may not be present and these pockets could release further down the slope. As always, practice safe travel protocol, expose one person at a time, have escape routes planned and watch your partners.
Deep Persistent Slabs: Buried in the middle and toward the bottom of the snowpack are old weak layers of facets and buried surface hoar. These layers formed in January and though they have not been responsible for avalanche activity for over a month or more, the springtime warm up can re-activate old layers. Although very unlikely an avalanche will release in these, it’s good to remember our snowpack has a poor structure. Most concerning areas are those with a thin snow cover such as the Girdwood Valley and the South end of Turnagain Pass and Summit Lake.
Small slab avalanche triggered remotely on Tincan’s Notherly aspect.
Wet avalanche activity will again be a concern later in the day on sunlit aspects. Several wet loose avalanches were seen yesterday both natural and human triggered. All these we know of were generally small and easily avoided. Today will likely be a similar scenario. Temperatures are warm this morning at the higher elevations and even with clouds expected later today, the surface crusts are likely to soften. Once the sun crust melts and the snow becomes wet and ‘punchy’ to your boot, it’s time to head to more shaded slopes. Even a small wet snow avalanche can push you around somewhere you don’t want to go.
Wet Slabs: We have not seen any confirmed wet slab avalanche activity yet, but this could be just around the corner. There was a natural slab avalanche on a Westerly aspect in Portage Valley noted yesterday. We don’t have quite enough details, but this could be a sign wet slabs may begin to occur if warm days continue.
Wet loose avalanches on Pete’s South, on the Southerly end of Turnagain Pass.
Slab avalanche seen yesterday in Portage Valley
Sunny skies were over the region yesterday. Temperatures climbed into the mid 40’s F at 1,000′ and near 30F along the ridgetops. Overnight, valley bottoms have cooled into the upper 20’s F while warm air streaming in aloft has kept ridgetop temperatures warm. In fact, the Sunburst weather station has jumped from 27F to 32F since midnight. Ridgetop winds were light from the Northwest, in the 5-10mph range, during the day before shifting Easterly along with the warm air moving in around midnight.
Today, clear skies are expected this morning before cloud cover moves in later in the day. This is associated with a low pressure spinning in the Gulf slowly moving our way. There is a chance for a few snow flurries tonight, adding a trace of new snow (with light rain below 1,500′). Ridgetop winds will remain Easterly in the light to moderate range (5-15mph). Temperatures will again be warm. Ridgetops should see high temperatures in the 30-35F range while valley bottoms warm to the upper 40’sF.
For Monday and Tuesday, the low pressure system in the Gulf will move in and should keep skies mostly cloudy. There will be a chance for a few inches of new snow above 2,000′ and light rain below as temperatures remain spring-like.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||35||0||0||80|
|Summit Lake (1400′)||34||0||0||33|
|Alyeska Mid (1700′)||35||0||0||77|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||32||NW||5||14|
|01/19/20||Turnagain||Avalanche: south facing aspect on 3800ft bump just northeast of 4940||Anonymous|
|01/19/20||Turnagain||Avalanche: Cornbiscuit & Magnum||Allen Dahl|
|01/19/20||Turnagain||Observation: Eddie’s||Kakiko Ramos-Leon|
|01/18/20||Turnagain||Observation: Sunburst||Ryan Van Luit Forecaster|
|01/18/20||Turnagain||Avalanche: Sunburst||Eric Roberts|
|01/18/20||Turnagain||Avalanche: North end Tincan trees||Heather Johnson|
|01/17/20||Turnagain||Observation: Tincan||Allen Dahl|
|01/16/20||Turnagain||Observation: Lynx Creek||Wagner / Van Luit Forecaster|
|01/13/20||Turnagain||Observation: Tincan||Ryan Van Luit Forecaster|
|01/12/20||Turnagain||Observation: Magnum West face||Levi Oyster|
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.