Haines Avalanche Center

Forecast Expired - 03/06/2021

Above 2,500ftConsiderable

1,500 to 2,500ftConsiderable

Below 1,500ftConsiderable

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Deep Slab:

DONT WAKE THE DRAGON. We still have a deep-persistent weak layer 1m deep that consists of a thick facet layer that is prone to collapse. On steep enough slopes, this could lead to an avalanche.

The fact that we have not been seeing much natural avalanche activity is not a good sign. It means that all of the stress that has been slowly building over the last two weeks (3-4″ of SWE) has not been released. Here’s what we know:

  • 1m of new snow sits over a very weak facet layer that has been reactive to human weight over the last week.
  • The deep facet layer is widespread below 3000ft. Above 3000ft, it is less widespread but still present in many areas.
  • While you may be able to “thread the needle” and find slopes with good stability, this is a very difficult task and the stakes are quite high.
  • Heavy triggers like cornice falls, loose-sluffs, and snowmachine drops are more likely to trigger the deep weak layer.
  • Any slabs that break 1m deep are likely to be deadly.
  • South aspects are getting baked by strong solar radiation when the sun comes out, which will weaken the snowpack

 

 

Bottom line is a complex picture with possibly deadly consequences. Treeline areas are sketchy, no doubt. While there may be slopes in the alpine where the facet layer is not present, they will be very hard to map out, and will probably involve traveling through sketchy areas to get there.

 

 

 

We are entering the most deadly time of year in Haines. Early March has historically brought tragic accidents with large avalanches that break much wider than expected.

 

(Lutak Zone 2/26. Poor structure and easy shears below 40cm (now 90cm) of new snow on a knife hard melt-freeze crust with facets above and below crust. Multiple interfaces with varying degrees of strong over weak layering that included surface hoar. Whumphing and shooting cracks near this pit and a visible natural avalanche that ran on the new snow/old snow interface (see Avalanche Activity section). Photo: HAC)

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Falling Cornice:

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 3

Wet Avalanches:

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

  • February 26th – Recent Natural D2 storm slab NE-asepct at 3100′. Lutak Zone.

(Lutak Zone 2/26. Recent natural D2 Storm Slab released at convexity. NE aspect 3,100′. Photo: Jeff Moskowitz)

  • February 21st – Reports of D2 storm slab on S-aspect from 1800′ – 1500′.
  • February 23rd- Reports of low angle natural activity this past Tuesday below 1500′.
  • February 4th – D2 pocket is a good example of old wind slabs in cross-loaded pocket 1500′.

(Transitional Zone 2/4.D2 Slab in cross-loaded terrain. Transitional Zone, NE aspect, 1500ft. Photo: Erik Stevens)

Weather

In the last week we have received around 1.5″ of SWE at Flower mountain, and 2.5″ of SWE near Haines. This has been a slow steady loading event. Winds have been light and variable. Another wave of snow moves in Friday night-Saturday, with a few inches likely. After that, high pressure moves in with clear, mostly calm and cool conditions.

 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   140″+*  2″ / 0.15* 5″ / 0.40*   500′  light, var  2″ / 0.15*
Flower Mountain @ treeline  105″  2″ / 0.15  3″ / 0.20  500′  light, var  1″ / 0.05*
Chilkat Pass @ 3,100ft  63″   1″ / 0.10  1″ / 0.10  500′  light, var  0″ / 0.00*

( *star means meteorological estimate )

—The Mt. Ripinsky weather station is completely buried and no longer reporting.—

Additional Information

Practice like you play. Make sure all your rescue gear it is fully functional and your beacon has full 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:

Alerts

Click the + Full Forecast link below for each zone to read more. BOTTOM LINE THIS WEEKEND: We still have a complex snowpack, with a weak layer 1m deep that is not yet settled. Keep your safety margin extra wide.