Haines Avalanche Center

Forecast Expired - 02/03/2022

Above 2,500ftConsiderable

1,500 to 2,500ftConsiderable

Below 1,500ftModerate

Degrees of Avalanche Danger

Low
Moderate
Considerable
High
Extreme

Avalanche Problems

Problem 1

Persistent Slab:

Aspect:  All aspects, especially wind-protected basins, aprons below steep terrain (see photos in Avalanche Activity Section below)

Elevation:  Treeline and above.

 

Bottom Line:  Surface hoar was observed in this zone on Jan 20th. 2-4ft of new snow and wind slabs now lay on top of this dangerous weak layer. More recent wind slabs may also be tender and lurking.  Careful snowpack evaluation, cautious route finding and conservative decision making are essential.  Human-triggered avalanches are likely in the alpine, and may break wider than expected (see wide propagation in the Avalanche Activity Section below). This layer was active during the last storm, and many slopes may be on the brink, waiting for a trigger.

 

Travel Advice: 

  • Think about any steep connected terrain and how a slab could propagate wider than expected
  • Avoid similar terrain to the photos of recent avalanches (Avalanche Activity Section below)
  • Look for recent natural avalanches.
  • Watch for red flags: shooting cracks and collapsing (whumphing).
  • Give a wide travel margin to suspect slopes, travel one-at-a-time, eyes on!
  • Avoid terrain with traps and complexity.
  • Use travel test pits to identify any suspect layers. Buried surface hoar is difficult to find in a snowpit without careful testing and shearing off layers.

 

Surface Hoar from Flower Mountain on 1/20/2022

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

From 1/29 to 2/1, several reports came in of recent avalanches in the alpine. The common characteristics of these slides were wide propagation, and failing 2-5ft deep at the interface below the wind slabs from last week’s atmospheric river. We have strong reason to suspect these slides occurred on a buried surface hoar layer from 1/20. They happened on all aspects, at elevations from 3000 – 5000ft, and all were in wind sheltered areas below ridges, features, and starting zones. Slide were observed in the Transitional and Lutak zones.

Weather

Forecast:

Light snowfall begins Thursday morning, and will become heavy by nightfall. 10-16″ of new snow is expected by midday Friday. Sometime Friday afternoon, we expect south winds to come in and raise snow levels to near 1000ft. A new storm Saturday evening-Sunday will likely bring an additional 1.5-2″ of precipitation (16-24″ of snow) with freezing levels remaining near 1000ft.

 

Seasonal Summary:

  • Feb 1st brought in about 6″ of cold smoke pow
  • Jan 27-29 brought 1.5 – 2.4″ of SWE with freezing levels near 1500ft.
  • An Atmospheric river hit Jan 21-22. It brought in 2-7″ of SWE (2-5ft of snow above 2500ft, mostly rain below)
  • Jan 9th-15th brought 24-48″ of new snow in the alpine, with some light rain up to 3,500ft, followed by heavier rain up to 2000ft.
  • Very strong NW winds and arctic temperatures blasted the area the first week of January
  • Jan 1st: New snow (20″ in Lutak, 7″ Transitional zone) buried any preserved surface hoar.
  • Moderate NW winds hit exposed slopes Dec 19-20th
  • Surface hoar formed on all aspects and elevations Dec 17-18th
  • December brought in about 2-5 feet of snowfall (highest in Lutak zone), and a few strong NW wind events
  • November brought consistent heavy snowfalls, cold weather, and SE winds
  • October brought heavy snow in the alpine, followed by a few rain/sun crusts
 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 **  100″ *  0″ / 0.00″*  6″ / 0.20″*  0′  mod, NE    16″ / 1.00*
Flower Mountain @ treeline  72″  0″ / 0.00″  5″ / 0.20″  0′  mod, SE   10″ / 0.75 “
Chilkat Pass @ 3,100ft  30″  0″ / 0.00″  8″ / 0.20″  0′  light, N   6″ / 0.35*

( *star means meteorological estimate )

** The Ripinsky weather station is in need of repair, and will likely be down until Summer.

Additional Information

Safe backcountry travel requires training and experience. You control your own risk by choosing where, when and how you travel. Ride rescue ready. Be prepared for an emergency. Prevent hypothermia. Carry bear spray. Winter is a high consequence environment.

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.

 

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