Haines Avalanche Center

Forecast Expired - 01/13/2022

Above 2,500ftConsiderable

1,500 to 2,500ftConsiderable

Below 1,500ftConsiderable

Degrees of Avalanche Danger

Low
Moderate
Considerable
High
Extreme

Avalanche Problems

Problem 1

Wet Avalanches:

Aspect: all aspects

Elevation: Treeline and below

 

Bottom Line: Earlier this week we had around 25″ of new upside-down snow in this zone, followed by a major warm up and rain-on-snow. You are likely to encounter wet surface snow below treeline today, and human triggering of heavy wet sluffs and slabs will be likely in terrain steeper than 33 degrees.

 

Travel Advice: Conditions are most sketchy in the lower elevations. Expect the new snow to move around, so you should avoid steep terrain. Especially watch out for terrain traps where even small slides could pile up quite deep.

 

See Wind Slab problem for above treeline travel advice.

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Wind Slab:

Aspect: Mainly on wind loaded W-NW-N-NE aspects

Elevation: Treeline and above

 

Bottom Line: We just had a dramatic change to our snowpack.  SE winds blew pretty hard this week in the Alpine, with tons of new snow. New wind slabs have built up in any wind loaded areas, and will be sitting on weak snow that fell Sunday. Avalanches will be possible within the new snow, and failing on the new/old snow interface. Heavily wind loaded areas may hold enough critical loading to trigger deep persistent weak layers, which could cause wide propagation and very large avalanches.

 

Travel advice: It will be helpful to dig around in the snow and look for potential weak layers on any slope you plan to ride. You will need to assess how well bonded new wind slabs are, and whether there are deep weak layers that could be triggered. Always use safe travel techniques such as only exposing one person at a time both on the way up and down. Identify and avoid thin areas where weak layers are more likely to trigger a slide from. Group up in safe zones that are out of harms way.

 

Wind slabs triggered in the upper snowpack may be able to step down to deeper persistent weak layers:

 

  • On wind-protected slopes, there is preserved buried surface hoar about 5-10″ deep
  • Snow and wind events in December created layers of slab and weak, facetted snow
  • Cold temperatures Dec. 3-5th created weak snow at the surface that is now buried in many places
  • Over a meter deep: old weak layers are buried and difficult to trigger, but still there.
  • Toward the very bottom: early season snowfalls and crusts linger and are very difficult to trigger but are still of concern for step-down potential.

5-10mm surface hoar observed Dec. 18/ Test pit from Jan. 1st with buried crust 70cm down

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

There have a few reports of small skier triggered slides in steep areas below treeline, involving the new snow.

Weather

Forecast:

A new warm, moist storm is expected to arrive Thursday evening. Snow levels are likely to start around 1,000ft, and may drop to sea level by Friday morning. Winds will be moderate out of the south over the mountains. Heavy precipitation is likely to continue into Friday, with 12-24″ of new snow likely above 1000ft.

Seasonal Summary:

  • A strong storm brought 16-36″ of new snow Jan 9th-11th, finishing with some light rain up to 3,500ft.
  • 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*  10″ / 1.00*  700′  light, SE  15″ / 1.25*
Flower Mountain @ treeline  55″  0″ / 0.00  5″ / 0.50  0′  light, SE  10″ / 0.90*
Chilkat Pass @ 3,100ft  18″  0″ / 0.00  1″ / 0.10  0′  light, SE  5″ / 0.50*

( *star means meteorological estimate )

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

Additional Information

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.

 

Education Video Links:

Alerts

Recent Sled Avalanche Case Studies Zoom Link: https://us06web.zoom.us/j/83953218614?pwd=UVhXMUVQQ21ZQVNiQ0gweXJ4UmxqUT09

Earlier this week we had around 25″ of new upside-down snow in this zone, followed by a major warm up and rain-on-snow. You are likely to encounter wet surface snow below treeline today, and human triggering of heavy wet sluffs and slabs will be likely in terrain steeper than 33 degrees.