Haines Avalanche Center

Forecast Expired - 02/13/2022

Above 2,500ftModerate

1,500 to 2,500ftModerate

Below 1,500ftModerate

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Persistent Slab:

Aspect: All aspects, especially wind loaded terrain.

Elevation: Above Treeline

 

Bottom Line: Very few visible clues on the surface exist to tell us where this avalanche problem is hiding, as human triggered avalanches are possible and natural avalanches are unlikely. This problem is more susceptible to human triggering in specific features and may not produce spontaneous avalanches, thereby keeping observations minimal. You have a higher likelihood of triggering these buried layers near shallow and exposed terrain areas. Additionally, in areas where fresh, hard wind slab in the alpine may be waiting for a trigger – especially on high, cold, steep aspects where snow was available for transport. These wind slabs could create step down potential into deeper, persistent layers. There is uncertainty on how deep this problem is lurking. Due to the nature of the current persistent problem, snow pit test results and observations can at times be unreliable due to a lack of feedback.

 

Our snowpack was nuked over the last week: first with heavy snowfall, then strong warming, then more heavy loading. Added up, there was 5″ of new SWE (5 feet of new snow above 3000ft) in this zone. This stressed our previous weak layers and probably caused a natural avalanche cycle. The next storm is likely to produce new instabilities near the surface. Below 3,000ft hard surface conditions exist from warming last week and cooling trend from Thursday,

 

Travel Advice:

  • Think about the consequences of a deep, wide hard slab breaking before you commit to a slope. How can you avoid triggering an avalanche? What is your plan if one is triggered? Always reduce your exposure to these risks as much as possible. Travel one-at-a-time in avalanche terrain, and only group up in safe areas, with a wide safety margin.
  • Stick to slopes less steep than 30-degrees while in the alpine. If you choose to venture onto steeper slopes, carefully evaluate them by digging, probing, and testing them.
  • Look for shooting cracks, whumphing or collapsing that indicate a stiffer slab over weaker snow. 
  • Hard wind slabs can break above you, take into consideration extra safety margins.
  • Probe and feel for slabs underneath you.

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Avalanche Activity

First Photo: Deep slab natural avalanche that occurred roughly 1/29 in the Lutak Zone. This slide may have run on a buried facet layer from late December’s outflow event, or even a deeper rain crust near the ground (it went all the way to ground in spots).

Last two photos: From 1/29 to 2/1, several reports came in of recent avalanches in the alpine of the Transitional Zone. The common characteristics of these slides were wide propagation, and failing 2-5ft deep at the interface below the wind slabs from last week’s atmospheric river. We have strong reason to suspect these slides occurred on a buried surface hoar layer from 1/20. They happened on all aspects, at elevations from 3000 – 5000ft, and all were in wind sheltered areas below ridges, features, and starting zones. Slide were observed in the Transitional and Lutak zones, but the Lutak slides appear to be on different layers.

 

4Winds zone.  SW.  4000-5000′

Near Mt. Kraus.

 

Weather

Forecast:

Mostly cloudy with a signifcantly drier day compared to the last several. Temperatures in the high 20s with Light NW winds. Patches of freezing fog could linger throughout the morning, primarily out the highway.

Seasonal Summary:

  • Feb 5th-9th brought snow levels near 3,500ft, and 2.5-4″ of SWE with strong south winds.
  • Feb 1st-4th brought in 12-24″ of low density powder.
  • Jan 27-29 brought 1.5 – 2.4″ of SWE with freezing levels near 1500ft.
  • An Atmospheric river hit Jan 21-22. It brought in 2-7″ of SWE (2-5ft of snow above 2500ft, mostly rain below)
  • Jan 9th-15th brought 24-48″ of new snow in the alpine, with some light rain up to 3,500ft, followed by heavier rain up to 2000ft.
  • 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 **  122″*  2″ / 0.25″*  7” / 0.60″*   0′ – 1000′  Light, NW   0″ / 0.0*
Flower Mountain @ treeline  73″  0″ / 0.0″  5″ / 0.40″   0′  Light, NW   0″ / 0.0 “
Chilkat Pass @ 3,100ft  30″  1″ / 0.10″  4″ / 0.20″   0′  Light, NW   0″ / 0.0”

( *star means meteorological estimate )

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

Additional Information


Safe backcountry travel requires training and experience. You control your own risk by choosing where, when and how you travel. Ride rescue ready. Be prepared for an emergency. Prevent hypothermia. Carry bear spray. Winter is a high consequence environment.


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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.

 

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