|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|
Say it isn’t so…the northwest winds look to be arriving. It may be a sunny day out there, but expect cold and windy conditions along the ridgelines. The forecast is for sustained speeds of 25-35 mph. We know from past wind events, this can result in stronger winds along Turnagain Arm and Portage Valley, through Crow Pass and in Summit Lake. Turnagain Pass can sometimes be spared much of the wind, but not always. In fact, this NW flow is notorious for channeling through the Pass from the south, loading northerly aspects on the non-motorized side of the road. Sometimes this occurs just at the mid-elevations, while the peaks remain in the NW flow. This direction can also top-load Seattle Ridge as winds load the road-side SE face of the ridge. In short, it’s a day to watch for what the winds are doing, or hopefully not doing…
Areas the winds are impacting: With a foot or more of very loose unconsolidated surface snow available for transport at the mid and upper elevations, touchy wind slabs should easily form where wind loading is taking place. The higher in elevation, the more wind and loading is expected. Not only will fresh wind slabs be easy to trigger, natural wind slab avalanches are also possible. Expect them to vary in size, from shallow and only 6″ thick to up to 2′ in places. Although outside of our forecast zone, this flow will often produce a natural wind slab cycle in the central Kenai Mtns, including Summit Lake.
Areas out of the wind: If you find yourself in an area without wind effect, remember to watch for old wind slabs around a foot thick that could be resting on buried surface hoar and facets. Although becoming less likely to find, there is still a chance a persistent slab avalanche could be stumbled upon and triggered. What is more likely in areas out of the wind is sluffing in steep terrain. Sluffs have been running fast and gaining volume with the loose faceting surface snow.
Cornices: Winds today may build and break off chunks of cornices, which could in turn trigger a wind slab below. Otherwise, it will be the normal caution routine of giving cornices a wide berth and limit time under them.
A look at the top foot of the snowpack on Tincan from yesterday. Note the loose snow above the buried surface hoar. 2.5.21.
There have been no recent reports of glide cracks releasing. However, cracks are still opening up and moving. This tells us that releases are possible and as is common practice, avoiding being under cracks is prudent. These are completely unpredictable beasts.
Yesterday: Overcast skies were over the region most of yesterday as a band of clouds moved through. No precipitation was reported and temperatures were pleasant (~20F) along ridgetops while valley bottoms hovered in the single digits. Ridgetop winds were light from the west.
Today: Skies have cleared again and a sunny day is on tap. The big news is the northwest winds. These increased overnight and are expected to continue through today along the ridgelines in the 25-35mph range with stronger gusts. Temperatures have dropped with more cold air streaming in. Upper elevations will be near 10F while mid elevations could stay in the teens and valley bottoms are in the single digits.
Tomorrow: Sunny skies and continued cold temperatures are expected for Sunday and into Monday. Ridgetop northwest winds are forecast to ease to the 10-20mph range. A hint of precipitation with cloudy skies is showing up on models for the mid to latter part of the week.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||17||0||0||119|
|Summit Lake (1400′)||7||0||0||44|
|Alyeska Mid (1700′)||13||0||0||109|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||18||NW||8||24|
|03/06/21||Turnagain||Observation: Eddies/Tincan||A Schauer Forecaster|
|03/05/21||Turnagain||Observation: Seattle Ridge – SE face, road side||CNFAIC Staff Forecaster|
|03/05/21||Turnagain||Observation: Tincan, north side||W Wagner Forecaster|
|03/04/21||Turnagain||Observation: Magnum Peak||Carson Jones|
|03/02/21||Turnagain||Observation: Pastoral||Schauer/ Wunnicke Forecaster|
|03/01/21||Turnagain||Observation: Tincan||Schauer/ Rothman Forecaster|
|02/28/21||Turnagain||Observation: Lynx Creek||Graham --AAS Moto Level 1|
|02/28/21||Turnagain||Avalanche: Tincan||Mike Records|
|02/28/21||Turnagain||Observation: Eddies||Andy Moderow|
|02/25/21||Turnagain||Observation: Seattle flats, above power line||Carly AAS Level 1|
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.