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ARCHIVED - Forecasts expire after 24 hours.
Issued
Sat, January 27th, 2024 - 7:00AM
Expires
Sun, January 28th, 2024 - 7:00AM
Forecaster
John Sykes
Avalanche risk The Bottom Line

The avalanche danger remains MODERATE above 1000′ due to the threat of glide avalanches releasing up to 7′ deep and causing very large avalanches. These avalanches occur at random times on slopes with existing glide cracks, so being aware of any glide cracks on the slopes above you is critical to avoid this hazard. Gap winds gusting up to 30 mph+ are expected along Turnagain Arm which could cause small wind slabs 6-12″ deep in steep terrain. Below 1000′ the avalanche danger is LOW.

Special Announcements

Events TODAY!!

  •  POSTPONED! Anchorage: Avalanche Rescue Skills Workshop. This event is being postponed to a later date (TBD) due to extremely cold temperatures. We will post the new date as soon as it’s determined.
  • Moose Pass: Winter Rendezvous – Trail Lake Lodge – Jan 27, stop by between 10-1pm to chat with the new forecaster Daniel Krueger, ask your questions, and learn more about avalanche information on the Kenai.

SnowBall 2024!:  Mark your calendars for Valentine’s Day, Feb 14 (7-11pm @ 49th St Brewing). Details and tickets HERE. The evening promises costumes, finger food, a rocking band, silent auction, and of course plenty of great company. Join us in supporting Chugach Avy as well as our friends at the Alaska Avalanche School.

Sat, January 27th, 2024
Alpine
Above 2,500'
2 - Moderate
Avalanche risk
Treeline
1,000'-2,500'
2 - Moderate
Avalanche risk
Below Treeline
Below 1,000'
1 - Low
Avalanche risk
Sun, January 28th, 2024
Alpine
Above 2,500'
2 - Moderate
Avalanche risk
Treeline
1,000'-2,500'
2 - Moderate
Avalanche risk
Below Treeline
Below 1,000'
1 - Low
Avalanche risk
Sun, January 28th, 2024
Alpine
Above 2,500'
2 - Moderate
Avalanche risk
Treeline
1,000'-2,500'
2 - Moderate
Avalanche risk
Below Treeline
Below 1,000'
1 - Low
Avalanche risk
0 - No Rating
1 - Low
2 - Moderate
3 - Considerable
4 - High
5 - Extreme
Avalanche risk Avalanche risk Avalanche risk Avalanche risk Avalanche risk
Travel Advice Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential. Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
Likelihood of Avalanches Natural and human-triggered avalanches unlikely. Natural avalanches unlikely; human-triggered avalanches possible. Natural avalanches possible; human-triggered avalanches likely. Natural avalanches likely; human-triggered avalanches very likely. Natural and human-triggered avalanches certain.
Avalanche Size and Distribution Small avalanches in isolated areas or extreme terrain. Small avalanches in specific areas; or large avalanches in isolated areas. Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. Large avalanches in many areas; or very large avalanches in specific areas. Very large avalanches in many areas.
Recent Avalanches

It is possible that another glide avalanche released above the Seattle Ridge uptrack either yesterday or overnight last night. The lighting conditions on the RWIS camera are not good enough to be 100% confident, but it appears that sometime in the past 24 hours another glide crack released directly above the normal route up. We will need to wait for light of day to confirm, but this would continue the trend of active glide avalanche activity that we have been seeing for several weeks.

Turnagain Pass RWIS camera showing the older glide avalanches (blue) and the possible new avalanche (red) with the rough location of the uptrack in yellow. Photo 1.27.24

Avalanche Problem 1
  • Glide Avalanches
    Glide Avalanches
  • Aspect/Elevation
  • Certain
    Very Likely
    Likely
    Possible
    Unlikely
    Likelihood
  • Historic (D4-5)
    Very Large (D3)
    Large (D2)
    Small (D1)
    Size
Glide Avalanches
Glide Avalanches are the release of the entire snow cover as a result of gliding over the ground. Glide avalanches can be composed of wet, moist, or almost entirely dry snow. They typically occur in very specific paths, where the slope is steep enough and the ground surface is relatively smooth. They are often proceeded by full depth cracks (glide cracks), though the time between the appearance of a crack and an avalanche can vary between seconds and months. Glide avalanches are unlikely to be triggered by a person, are nearly impossible to forecast, and thus pose a hazard that is extremely difficult to manage.

Aspect/Elevation of the Avalanche Problem
Specialists develop a graphic representation of the potential distribution of a particular avalanche problem across the topography. This aspect/elevation rose is used to indicate where the particular avalanche problem is thought to exist on all elevation aspects. Areas where the avalanche problem is thought to exist are colored grey, and it is less likely to be encountered in areas colored white.

Likelihood of Avalanches
Terms such as "unlikely", "likely", and "certain" are used to define the scale, with the chance of triggering or observing avalanches increasing as we move up the scale. For our purposes, "Unlikely" means that few avalanches could be triggered in avalanche terrain and natural avalanches are not expected. "Certain" means that humans will be able to trigger avalanches on many slopes, and natural avalanches are expected.

Size of Avalanches
Avalanche size is defined by the largest potential avalanche, or expected range of sizes related to the problem in question. Assigned size is a qualitative estimate based on the destructive classification system and requires specialists to estimate the harm avalanches may cause to hypothetical objects located in the avalanche track (AAA 2016, CAA 2014). Under this schema, "Small" avalanches are not large enough to bury humans and are relatively harmless unless they carry people over cliffs or through trees or rocks. Moving up the scale, avalanches become "Large" enough to bury, injure, or kill people. "Very Large" avalanches may bury or destroy vehicles or houses, and "Historic" avalanches are massive events capable of altering the landscape.

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
More info at Avalanche.org

Glide avalanches continue to be our main concern due to their widespread distribution across the forecast area and the frequent glide avalanche activity we have been observing for several weeks now. Glide cracks can fail at random times regardless of the current weather or snowpack conditions and cause very large avalanches up to 7′ deep. To avoid this hazard it is important to be aware of any glide cracks on slopes above you and try to minimize the amount of time you spend underneath. Glide cracks can be surprisingly hard to see depending on the size of crack, shape of the slope, and visibility conditions. If you can’t avoid travelling underneath a glide crack we recommend traveling as quickly as possible and spreading out your group.

For the most part winds are expected to be light today, but in gap wind areas like along Turnagain Arm we could see wind gusts of 30 mph+. These winds could be strong enough to form some small wind slabs in steep terrain. However, the snow surface is already pretty wind affected which means there is not much soft snow left to be transported by today’s winds.

Over the past two and a half weeks we have been in a dry and cold spell which has kept the avalanche conditions consistent and generally safe with the exception of the glide situation. It is possible that could change tomorrow evening, with the potential for a storm system to move into the area and bring heavy snowfall overnight Sunday and into Monday. This would be a welcome refresh for our surface conditions, but could also rapidly increase the avalanche danger. The weather experts at NWS have a high degree of uncertainty about the track of the storm system tomorrow, so it is probably best not to get our hopes too high but we want to be aware of the potential change coming our way.

Many glide cracks on S face of Cornbiscuit. Photo from Kakiko Ramos-Leon 1.26.24

Weather
Sat, January 27th, 2024

Yesterday:  Clouds moved in during the morning and lingered throughout the day causing occasional snow showers and leaving a trace to 1″ of new snow. Temperatures remained in the positive to negative single digits F at low elevations and dropped into that same range at upper elevations. Winds speeds were light with averages of 0-5 mph and gusts up to 15 mph.

Today:  Temperatures are going to be frigid today, in the -10 to 0 F range at all elevations. Thankfully winds are expected to be light in the 0-10 mph range with gusts possible up to 15 mph. Stronger wind gusts up to 35 mph are expected in gap wind areas like Turnagain Arm or Seward. Some cloud cover is expected to move through the area but models still indicate that most of the clouds will stay to our east, leaving us with one more day of mostly sunny skies.  No new snowfall is expected, but that was the story yesterday as well and there were some snow showers throughout the day.

Tomorrow:  The weather pattern is expected to change tomorrow, but there is a lot of uncertainty in how things will play out. Our best estimate is that cloud cover and snowfall will move into our area tomorrow afternoon or evening and continue overnight and into Monday. Due to the late arrival of the snowfall there no real accumulation expected during the day on Sunday. Temperatures should rise from the negative single digits to the positive single digits throughout the day tomorrow. Winds are expected to remain light with averages in the 5-10 mph range.

PRECIPITATION 24-hour data (6am – 6am)

Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 3 1 0.1 77
Summit Lake (1400′) 3 trace 0 n/a
Alyeska Mid (1700′) 4 trace 0.01 73
Bear Valley – Portage (132′) 7 1 0.1
Grouse Ck – Seward (700′) 10 1 0.1 50

RIDGETOP 24-hour data (6am – 6am)

Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 6 variable 5 17
Seattle Ridge (2400′) 2 NNE 3 13
Observations
Recent Observations for Turnagain Pass
Date Region Location
02/24/24 Turnagain Observation: TinCan Backdoor/ Center Ridge
02/22/24 Turnagain Avalanche: Lynx Creek
02/22/24 Turnagain Observation: Turnagain, Seattle, Mt Ascension
02/21/24 Turnagain Observation: Tincan Trees
02/21/24 Turnagain Observation: Sunburst
02/20/24 Turnagain Avalanche: Tincan
02/20/24 Turnagain Observation: Seward Highway across from Johnson Pass TH
02/19/24 Turnagain Avalanche: Base of Seattle Ridge
02/18/24 Turnagain Observation: Lynx creek
02/18/24 Turnagain Observation: Tincan Trees
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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.