With unrelenting cold and calm weather, our shallow snowpack continues to degrade into weak, sugary snow exposing more rocks daily. At the upper elevations this process has been slower and a poor snowpack structure persists in certain areas, which is our primary concern. Though the only avalanche activity we have heard of or seen for the past 10 days has been sluffs in the weak snow, there is still a concern a slab could be triggered breaking in the old October facets near the ground.
Snowpack observations from yesterday from two notorious upper elevation starting zones point to a steady decline in the potential to trigger one of these slabs. The most concerning places to trigger a slide are those with little or no previous traffic. There are many slopes that remain untouched due to difficult early season/low snow cover access.
Snow surface conditions:
There is a very thin layer of dust on the snow surface that is believed to have been deposited sometime on Friday/Saturday by the strong winds channeled through the Mat-Su Valley. The high winds likely entrained particles that were then carried by the NW winds through Turnagain Arm and deposited in our forecast zone. The dust on snow became more visible with elevation yesterday.
Above treeline a scattered thin wind crust can be found on the loose snow surface in exposed areas. Below treeline there is still very loose, unsupportable snow which is sitting under some quite impressive surface hoar growth.
Sidenote: With the earthquake yesterday evening, I’m wondering (or more accurately hoping) if any facets were shaken off the slopes?
Mid-level clouds moved in from the east yesterday associated with a multipart low pressure system spinning in the Gulf and even dropped a flake or two on Turnagain Pass. The clouds look to have reminded overnight and despite the cover, which helps to €œhold the heat in €, temperatures have decreased to a new seasonal low at all elevations, except sea level. Ridgetop weather stations are reporting -4 to 0F while treeline stations are -2 to 3F. The inversion is still firmly in place with sea level and valley bottoms in the -15 to -10F range. Expect clearing skies and temperatures to rise 5 degrees or so throughout the day. Ridgetop winds are luckily still light from the northeast, 2-5mph gusting 5-10mph, where they should remain today.
We are still waiting for snow and looking at the longer term model forecasts in hopes of seeing a €œfire hose € of moisture pointed at us. Unfortunately, we are going to have to keep waiting through the week – but it does look like there is hope for Saturday. It may not be the fire hose we want, but at least it is a substantial change in the pattern and we should finally see some precipitation.
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).
Kevin will issue the next advisory Wednesday morning, December 5th.
|04/19/21||Turnagain||Avalanche: Triangle, Seattle creek||Will Morrison|
|04/18/21||Turnagain||Avalanche: Turnagain Pass Road Obs||Andy Moderow|
|04/18/21||Turnagain||Observation: Seattle Ridge, approximately 300 yards south of the up track||Brent Byrne|
|04/17/21||Turnagain||Avalanche: Road obs||Johnston-Bloom / Moderow Forecaster|
|04/16/21||Turnagain||Avalanche: Seattle Ridge||Wendy Wagner Forecaster|
|04/16/21||Turnagain||Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge||CNFAIC Staff Forecaster|
|04/16/21||Turnagain||Observation: Sunburst||Lance breeding|
|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|
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.