Haines Avalanche Center

Forecast Expired - 12/03/2021

Above 2,500ftConsiderable

1,500 to 2,500ftModerate

Below 1,500ftModerate

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Wind Slab:

Aspect: All aspects and below terrain features

Elevation: Mainly Treeline and above

 

New snow this week is about 6-14″, and SE winds were strong Wednesday night! The wind calmed down and changed from SE-E to N-NW on Thursday.

  • In the alpine, wind slabs from the strong wind event Wednesday night have settled out slightly and may be more difficult to trigger but still possible.
  • However, active loading is now happening as Northwest winds are causing reverse loading at upper elevations.
  • These slopes are most likely to avalanche and should be avoided. Even small slopes with terrain traps can be hazardous.

Identify wind-drifted snow by looking for stiff or hollow surface snow, and looking for cracking, whumphing, natural avalanches, and or active wind loading – treat these areas as highly suspect. Probe for strong over weak layering, the recipe for an avalanche. You can find safer conditions in wind-protected areas with softer snow. 

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Persistent Slab:

 

Confidence: Low-Moderate

Elevation: Between 2,500ft to 4,000ft

 

Look and listen for deep whumping!

 

The lower snowpack in all zones contains one or more rain crusts from mid October. Weak snow above and below a crust may cause strong snow above it to fail and produce an avalanche. Keep in mind a lot of new snow has fallen in the last 2 weeks burying this layer of concern further down in the snowpack. It will be possible to trigger an avalanche on this layer, 1 meter or deeper. We expect this October rain crust will be a lasting problem as we go into winter so keep your guard up! This layer exists on all aspects, but observations are limited and uncertainty is high.

 

What is the best way to manage this risk? We can simply avoid alpine terrain that is about 30 degrees and steeper. Be aware that venturing on these steeper alpine slopes is relatively high risk currently. Persistent slabs require a wide safety buffer.

Another way to reduce your exposure to these deep 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.

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Weather

October brought heavy snow in the alpine, followed by a few rain/sun crusts. November has brought regular heavy snowfalls, adding up to 70+ inches so far. Winds have alternated between NW and SE.

Over the last week, temperatures hovered near freezing in the mountains, and winds have been from the SE. Snowfall this week has been around 6-14″. Temperatures have dropped and a couple more inches of snow is possible Friday. Winds have transitioned from SE to NW and are expected increase late Friday.

 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 **   70″ *  3″ / 0.30*  6″ / 0.60*  0′  Mod, NW  2″ / 0.12*
Flower Mountain @ treeline  49″  1″ / 0.10  5″ / 0.50  0′ Mod, NW  1″ / 0.10*
Chilkat Pass @ 3,100ft  27.5″  1″ / 0.05  2″ / 0.15  0′ Mod, NW  1″ / 0.15*

( *star means meteorological estimate )

** The Ripinsky weather station is currently down, we will try to get it working again soon

Additional Information

FREE Avalanche awareness and companion rescue practice first Friday December 3rd at the Haines Library from 3:30-5:30pm. This life-saving training is sponsored by the Alaska Department of Public Safety and Alaska State Troopers and hosted by the @hainesavycenter. Bring your beacon, shovel and probe for hands-on practice and informational presentation. For all ages, ability levels and user ground. Let’s kick off the season with knowledge and safety. Join us for Learn and Return!


Beware of deep treewells which can trap a person. It’s deep out there.


Become a sustaining Haines Avalanche Center Member by clicking the poster or visiting 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:

Announcements

Click the –Full Forecast– button below for more details. We need your observations! FREE Avalanche awareness and companion rescue practice first Friday December 3rd at the Haines Library from 3:30-5:30pm.