Haines Avalanche Center

Forecast Expired - 01/06/2022

Above 2,500ftModerate

1,500 to 2,500ftModerate

Below 1,500ftModerate

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Wind Slab:

Aspect: Most likely on SW-S-SE-E-NE

Elevation: Most likely At and Above Treeline

 

The Bottom Line: Extreme arctic outflow has blasted the slopes for the last 5 days. Wind loading has slowed down now that there is less snow available for wind transport. But…recently wind loaded areas are still harboring layers of slab that can be triggered by a human. The most suspect areas will be wind loaded rollovers, chutes, and gullies steeper than 30 degrees. 

 

Another note: Some very large cornices have formed on SW, S,  and SE aspects. As always, be sure to give cornices the proper respect: stay WAY back. When they fail, they always break further back than you would expect.

 

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Persistent Slab:

Aspect: All aspects, most likely on wind loaded aspects and features SW-S-SE-E.

Elevation: All elevations.

 

 

Travel advice: Consider any possible slopes harboring surface hoar as guilty until proven innocent. 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. Have good communication, including radios and a set plan in case of an emergency. Be practiced at companion rescue.

 

  • 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.

 

 

The persistent slab danger is not going away, it is standing by waiting for the right trigger. We have not had a crush and flush cycle, or stabilizing event. Keep in mind that most avalanches are triggered by someone in the group.

 

5-10mm surface hoar observed Dec. 18/ Test pit from Dec. 23rd 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

We had one report of a small skier-triggered soft slab 12/25 in the Lutak zone. It was on a cross-loaded S aspect gully, and likely ran on the 12/18 Surface Hoar layer.

 

Dec 11th: Natural slide on mount Ripinsky’s back bowl caused by wind loading. It ran over a persistent weak layer on a NE aspect at 3,000ft, was 200ft wide and ran 800ft, with a average slope angle measured on Google Earth of 35 degrees.

Weather

Cold arctic outflow will dominate through Friday. But we are expecting a major pattern change starting Saturday.  This will bring heavy precip and rapid warming by Sunday night. The most likely scenario is  12-16″ of new snow in the valleys (turning to rain Sunday night), with 24″ of snow possible above 1000ft.

  • 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 **   80″*  0″ / 0.00*  0″ / 0.00*  9′ strong, NW  0″ / 0.00*
Flower Mountain @ treeline  43″  0″ / 0.00  0″ / 0.00  0′ strong, NW  0″ / 0.00*
Chilkat Pass @ 3,100ft  14″  0″ / 0.00  0″ / 0.00  0′ strong,NW  0″ / 0.00*

( *star means meteorological estimate )

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

Additional Information


Be prepared for an emergency and hypothermia. Winter is a high consequence environment. Carry bear spray.


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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

Bottom Line: Arctic winds have blasted this zone at all elevations. Be wary of wind loaded areas and look, listen and feel for hollow areas and shooting cracks. Be cognizant of buried surface hoar that is harbored in some areas and has step-down potential. Click the –Full Forecast– button below for more details. Please submit your observations!