Haines Avalanche Center

Forecast Expired - 02/05/2023

Above 2,500ftModerate

1,500 to 2,500ftLow

Below 1,500ftLow

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Persistent Slab:

The Bottom Line: Multiple avalanches with very large propagation released last week. A few of them were remotely-triggered avalanches by snowmachines, which ran on buried surface hoar layers 2-6ft deep. Primed slopes remain, and although triggering may be unlikely, the consequences could be extremely destructive. Smaller avalanche in the upper snowpack could step down and release a massive deep slab avalanche.

 

Terrain management continues to be critical! Be prepared for an avalanche that can break very wide, and take out all the “safe” zones on a slope. Be extra careful not to group up in places that an avalanche can reach. Be diligent in practicing good group management, communication and decision making. Do not ski/ride on the same slope as another group. Travel one at a time or with enough spacing so that only one person is exposed to an avalanche path at any one time. 

 

 

Buried Surface Hoar Layers:

  • January 10th (pictured below on the 10th and then the 22nd) is now buried about 2-4 feet deep. It was very active during last week’s storm cycle. Reports of remote-triggered activity on this layer Jan 27-28.
  • The Dec 31 surface hoar layer is present in the Transitional and Pass zones, about 4ft deep. This layer has been active in pits, and caused some natural avalanches in early January
  • Buried SH layers are tricky — they’re hard to find, and may only exist in wind-protected areas. But anywhere they are present you should be highly suspicious of that slope. It would be best to avoid wind-protected pockets that may be harboring this dangerous weak layer. Make continual assessments on test slopes and with stability tests.

 

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Wind Slab:

NW winds in the alpine has cross loading in gullies/chutes on NE-E-SE-S aspects. This led to a few D2 avalanches near the Little Jarvis area. You may find these isolated fresh wind slabs in particularly wind-loaded alpine areas, and they will be tender to human triggering. Any smaller wind slabs could step down to deep weak layers and trigger a massive avalanche.

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 3

Deep Slab:

Old Melt Layers and Crusts:

  • A buried persistent weak layer about 6+ feet deep (The “Big Warmup” Layer, Formed Nov 17th) is still a concern. Numerous natural avalanches observed 1/27 likely on this layer.
  • A wide safety margin is necessary. This setup could produce avalanches that break wider than expected, and are most likely to be triggered from shallow trigger points like rocks or small trees. You could ride the same slope numerous times until that right spot produces a large destructive slide.

 

Photos of the “Big Warmup” facet layer in the Transitional Zone at 2500ft on 1/2 with test results ECTP18 that demonstrated propagation potential on this layer & Photo from Old Faithful on 1/12 of a 5″ thick layer of facets down 170cm.

 

Depth Hoar at the Ground (Above 3,000′):

  • October snow followed by long cold snaps created depth hoar at the ground in most areas.
  • You are most likely to human-trigger this layer from shallow spots around rocks, or trees, or have a surface avalanche step down to the ground on this layer. Any slides that break to the ground are likely to be deadly.

 

Photos shows 6-9mm advanced depth hoar at the ground down 180cm with ECTP 25 down 80cm on facets below a crust in the Haines Pass Zone at 4,000ft on a NE-aspect.

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

 

January 25-29th:

Isolated fresh D2 wind slab avalanches in cross-loaded gullies near the Little Jarvis/Klehini area.

Reports of two snowmachine-triggered slides at the Pass, one was this D2 up West Nadahini Creek above 4,000′ failed 2-7′ deep on an isolated terrain feature. (likely slid on buried surface hoar)

Recent Natural activity

R4D2.5 at the Pass, likely ran on buried surface Hoar, stepped down to depth hoar at ground. Photo by David Morisette, via MIN.

D3 NE aspect 6000′ near Nadahini with widespread propagation.

D3 cycle between 3000-6000ft. All aspects. Most were unsupported slopes or rocky areas. Crowns 1-3m deep, ran just above ground.

 

Multiple D2 that ran about 2ft deep. In wind protected areas.

 

2000-3000ft widespread full depth wet slabs and glide avys, all aspects.

D2 N aspect 4300ft sub bowl of Old Faithful failed down to near ground, confined to a smaller pocket.

D3 on SW aspect at Lutak Inlet, ran down to the water

D4 on Takhin Ridge

Weather

Forecast:

Mostly cloudy and pleasant, with a few bouts of light snow possible. Light NW winds and temperatures 15-25 F. The next storm comes in Sunday night, with potential for a foot of new snow (less accumulation up the highway) and increasing SE winds.

 

Recent Weather Summary:

  • Jan 17-26 brought around 5″ of precip (3-5feet of new snow above 3000ft), strong SE winds, and a noticeable warmup
  • Surface Hoar and Near Surface Facet growth Jan 8-10
  • A strong front brought 24-30″ of snow above 2000ft on Jan 2nd.
  • There was widespread Surface Hoar growth on Dec 31st.
  • Dec 23-26 brought 10-18″ of new snow and a sharp rise in temperatures from -10F to 30F along with variable winds
  • Dec 16-23 brought strong NW winds and arctic cold temperatures
  • Dec 15 brought warmth/light rain up to 2600ft
  • Complete Season Histories:     Transitional Zone     Lutak Zone
 Snow Depth Last 24-hr Snow/SWE Last 3-days Snow/SWE  Today’s Freezing Level   Today’s Winds Next 24-hr Snow/SWE
Mount Ripinsky @ 2,500′  92″  3″ / 0.25  4″ / 0.33″  0′  light, NW   0″ / 0.00″
Flower Mountain @ 2,500′  52″  0.25″ / 0.01″  3″ / 0.20″  0′  light, NW  0″ / 0.00″
Chilkat Pass @ 3,100ft  40″  .03″ / 0.007″  1″ / 0.08″  0′  light, NW  0″ / 0.00″

 

Additional Information

WEAR A HELMET! Be careful of rocks and hidden hazards. Be prepared for crevasses when on a glacier. 

Are your riding companions trained and practiced in avalanche rescue? Everyone in your group needs to have a beacon, shovel, and probe, and know how to use them. Our mountains have very limited cell coverage, carry an emergency communication device and enough gear to spend the night.

Avalanche Canada’s Daily Process Flow – Utilize this everyday you go out in the mountains.

Announcements

Click the +Full Forecast link below for each zone to read more.  If you see any recent natural avalanche activity, or signs of instability please submit an observation.