Haines Avalanche Center

Forecast Expired - 02/27/2023

Above 2,500ftConsiderable

1,500 to 2,500ftModerate

Below 1,500ftModerate

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Wind Slab:

The Bottom Line: Not a whole lot is changing, including the severe consequences of our avalanche problems. Be hypersensitive of terrain- it is an active way to manage our entrenchment.

 

When on or near avalanche terrain, be diligent on terrain selection, group management, and human factor.  Travel one at a time or with enough spacing so that only one person is exposed to an avalanche path at any one time. Be prepared for an avalanche that could step down to deeper instabilities, creating a slide that could 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. 

 

 

Moderate to strong NW winds blasted us this week, and are increasing again today. Reactive and highly variable, cohesive slabs of wind drifted snow are .5-2 feet deep and likely in the alpine. They also may break wider than anticipated as some could be sitting on buried surface hoar. Wind slabs can be avoided by sticking to sheltered or wind-scoured areas. Also from the wind, cornices might be unsupported, scoured, and weak. Tread carefully around them and limit your exposure to slopes below them. A cornice drop could cause a slide, with potential for a step down.

 

 

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Persistent Slab:

When seeking out wind protected zones, remember that wind-protected pockets may be harboring weak, buried surface hoar layers. Protected means preserved. 

 

Jan 25th melt freeze crust is ~3-4′ deep (with recent winds, there is a lot of variability on depth of this widespread layer) sitting on top of it are near surface facets, and buried surface hoar from Feb 1-4.

 

Snow pit from Feb 22 in Lutak (NE aspect 1800ft) showing persistent weak layers below the new snow from Feb 10-15.

 

Surface Hoar observed in sheltered N-NE areas of Lutak Feb 1.

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 3

Deep Slab:

An unlikely to trigger, but high consequence deep slab layer remains. The “Big Warm-Up layer” from Nov 17th is not to be forgotten about. Although currently dormant, a smaller slide triggered on the upper snowpack could step down and trigger this deadly beast.

Jan 25th melt freeze crust is ~3-4′ deep (with recent winds, there is a lot of variability on depth of this widespread layer) sitting on top of it are near surface facets, and buried surface hoar from Feb 1-4.

 

Lutak, Feb 4 PST 70/130 End down 130 rounding faceted polycrystals.

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

Feb 19-23: 6 different observations of natural avalanches in the transitional zone and in the Chilkat range. The natural D2 slides were on all aspects, a few on lower angle, all running on a mid-snow pack layer, and a majority with widespread propagation.

A larger, D3-R4 natural avalanche was observed near Four Winds on a S, SW aspect, down 60-120cm, it looked like a loose wet slide that maybe stepped down to a lower layer. Widespread propagation.

Feb 9: Glide cracks ~3000-3400′ in the transitional zone on N, NE aspects. Also notable was observation of reloading of bed surfaces on previous slides.

Jan 28: Lutak Zone

Glory Hole NW-aspect around 3,200′

Lutak NW-aspect around 3,200' Jan 28

 

Multiple wide propagating natural slides released during Jan 25-29th- a link to an archive of photos coming soon.

 

 

Weather

Forecast:

Sunday looks mostly sunny with increasing NW winds, which will likely cause blowing and drifting snow over ridgelines and through passes.

 

Recent Weather Summary:

  • Late Feb 20-Feb 23 a cold high pressure system with moderate to strong N, NW winds
  • Feb 19-Feb 20- warmer, solar effect on south aspects, valley fog on the 19th at ~1500-2000 ft.
  • Feb 12 freezing levels 1250ft
  • Incremental snow (more in Lutak zone) since Feb 5th, periods of moderate S/SE winds
  • Feb 1-4 Near surface facets on top of crust from Jan 25 warm-up
  • 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′  ~120″  0″ / 0.00  6″ / 0.30″  0′  mod, NW   0″ / 0.00″
Flower Mountain @ 2,500′  59″  0″ / 0.00  3″ / 0.30″  0′  mod, NW  0″ / 0.00″
Chilkat Pass @ 3,100ft  46″  0″ / 0.00  3″ / 0.15″  0′  mod, 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 every day 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.