Haines Avalanche Center
Above 2,500ftConsiderable
1,500 to 2,500ftModerate
Below 1,500ftModerate
The Avy Rose shows the forecasted danger by elevation and aspect. It adds more detail about where you are likely to find the dangers mentioned in the forecast. The inner circle shows upper elevations (mountain top), the second circle is middle elevations, and the outer circle represents lower elevations. Think of the Rose as a birds-eye view of a mountain, looking down from above. The rose allows our forecasters to visually show you which parts of the mountain they are most concerned about.
Degrees of Avalanche Danger
Avalanche Problems
Problem 1
Aspect: Most likely on wind loaded aspects and features SW-S-SE-E.
Elevation: Mainly at and above treeline.
Strong NW winds are expected today. You are likely to encounter fresh wind slabs and active wind loading in the alpine. Plenty of previous snowfall is primed for readily available transport. Additionally, while it has been a few days since recent snowfalls, there are unbonded weak layers between older wind slabs in the upper meter of the snowpack.
Identify wind-drifted snow by looking for stiff or hollow surface snow, and looking for cracking, whumphing and blowing snow – treat these areas as highly suspect. You can find safer conditions in wind-protected areas with softer snow.
Natural avalanches are possible and human triggered avalanches are likely at and above tree-line. Cautious route-finding and conservative decision-making is essential.
Beware of terrain traps (e.g. gully, rocks, dense timber, cliff, crevasse) or areas where snow could pile up quickly. Avoid traveling above or below terrain traps.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Problem 2
Aspect: All aspects.
Elevation: All Elevations.
Incoming cold weather will only serve to weaken buried layers. The persistent slab danger is not healing, it is just standing by waiting for the right trigger. Don’t be the trigger!
Recent stress tests have unearthed layers of concern that have propagation propensity and the potential to step down into deeper layers of the snowpack.
Persistent avalanche problems are tricky. The question is: When will stress over-ride strength and cause a slab to fail?
- Cold temperatures Dec. 3-5 created weak snow at the surface that is buried in many places under a strong wind slab in the upper snowpack.
- Over a meter deep layering suggests old weak layers are buried and difficult to trigger but still reactive.
- Toward the very bottom early season snowfalls and crusts linger and very difficult to trigger but are still of concern.
It could still be possible that any surface avalanches could step down to the deeper weak layers, rain crust, or even the ground in alpine areas.
- One of the best ways to reduce your exposure to deeper persistent weak layers would be to stick to areas of deeper snowpack (>1m deep). But be wary of hidden rocks that can act as trigger points, and thin areas around the margins of a slab.
- Manage the terrain by only exposing one person at a time to the hazard, use group up spots out of harms way, and carry radios for communication.
- Look and listen for whumping, and other signs of instability. Report any natural avalanche activity on these deeper layers.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Avalanche Activity
Reports from the last week: A large natural avalanche was reported on a west aspect near 3920 in the Lutak Zone (See Persistent Slab problem). We also had reports of natural avalanches above Chilkoot Lake. These slides were likely dated Dec. 1 when temperatures increased with strong winds from the South.
Weather
Winds will switch Northerly and temps will drop.
- Yesterday, moderate temps in the morning made way for the winds to switch northerly and a temperatures to begin to plummet. Expect to see single digits for the next couple days.
- A low pressure system introduced 6-8″ of precipitation, moderate southeast winds gusting strong and warming temperatures, especially near sea-level.
- We’ve had about 20″ of low-density new snow this week in the Lutak zone, and around 8″ in the Transitional zone.
- Nov. 28 – Dec. 4th, it snowed 6-14″. Winds switched from SE to NW and increased into typical northerly outflow as temperature plummeted into the single digits.
- October brought heavy snow in the alpine, followed by a few rain/sun crusts, followed by regular heavy snowfalls in November.
Snow Depth [in] | Last 24-hr Snow/SWE [in] | Last 3-days Snow/SWE [in] | Today’s Freezing Level [ft] | Today’s Winds | Next 24-hr Snow/SWE | |
Mount Ripinsky @ treeline ** | 67″ | 0″ / 0.0* | 10″ / 0.6* | 0′ | Strong, NW | 0″ / 0.00* |
Flower Mountain @ treeline | 49″ * | 0″ / 0.00 | 9″ / 0.70 | 0′ | Strong, NW | 0″ / 0.0* |
Chilkat Pass @ 3,100ft | 29″ | 0″ / 0.00 | 2″ / 0.10 | 0′ | Strong, NW | 0″ / 0.00* |
( *star means meteorological estimate )
** The Ripinsky weather station is in need of repair, and will likely be down until Summer.
Additional Information
Beware of deep treewells which can trap a person. It’s deep out there. Be prepared for an emergency and hypothermia. Winter is a high consequence environment. Carry bear spray.
Become a sustaining Haines Avalanche Center Member by clicking the poster or visiting dev.alaskasnow.org/joinHAC. Support local forecasts, observations, education and weather stations. Join a community of winter recreationalists. Benefit from collective knowledge and skills. Help keep your friends and family safe in the backcountry. Get a free limited edition mountain buff, or neck gaiter with a $50 membership (first 20 members!).
Practice like you play. Make sure all your rescue gear is fully functional and your beacon has NEW batteries. Make sure 1) everyone in the group has a functioning beacon, shovel and probe 2) knows how to use them and 3) has trained in companion rescue in the last year. Keep your skills fresh. If you head into the hills, watch out for red flag avalanche conditions, natural avalanches, whoomphing or collapsing, and shooting cracks.
Education Video Links:
- AIARE
- How to Practice Avalanche Rescue Snowmobile Edition: https://youtu.be/2ML499MMDfM
- AK Sled Shed Motorized Learning:
- Intro: https://youtu.be/aoagKHfGkxs
- Personal Electronics in Avalanche Terrain: https://youtu.be/2Vz9S0OEyFk
- Snowmobile Macgyver Tool Kit: https://youtu.be/4WBNu_t6Bbk
- Head and Face Protection: https://youtu.be/jIzW89wOyZI
- Pre-season prep: https://youtu.be/zJmrb8cZlR4
- My Transceiver: https://youtu.be/yblaDWP7Jf8
- BCA Avalanche Safety for Snowmobilers
- How to Fix Common Snowmobile Problems in the Field: https://youtu.be/g9fiTxEvuFk
- Sleducation: Avalanche Safety for Snowmobilers: https://youtu.be/EWFOd_9DYb8
- Intro to Avalanche Transceivers for Snowmobilers: https://youtu.be/6ZLSBmsceog
- Avalanche Transceiver Trailhead Test for Snowmobilers: https://youtu.be/rWoXbadFBsY
- Avalanche Transceiver Searching Use Snowmobiles: https://youtu.be/w1ucyI6LMXM
- BCA Avalanche Rescue Series
- Beacon Search 101: https://youtu.be/nnHXLVA2FcE
- Avalanche Probing 101: https://youtu.be/-0_yDN5Drzw
- Avalanche Shoveling 101: https://youtu.be/dGQg9o3vAkM
- Organizing a Backcountry Rescue: https://youtu.be/gywtmukgt8s
- Post Avalanche Patient Care: https://youtu.be/9FyIeUy4wpQ
- Backcountry Evacuation: https://youtu.be/WPF-dciefL8
- Complex Multiple Burials Backup Techniques: https://youtu.be/pB6AfY2KyYo
- National Avalanche Center
- Avalanche Problems Explained: https://youtu.be/DkbnT_9-cHU
- Intro to North American Avalanche Danger Scale: https://youtu.be/r_-KpOu7tbA
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