Haines Avalanche Center

Forecast as of 2019-01-29 at 08:00 am and expires on 2019-01-30

Above 2,500ftConsiderable

1,500 to 2,500ftConsiderable

Below 1,500ftModerate

Degrees of Avalanche Danger

Avalanche Problems

Problem Details

Problem #1: Storm Snow

For Tuesday-Wednesday: Human-triggered avalanches are likely within the storm snow on all slopes steeper than 28 degrees. 

Moderate to Heavy snow will fall over the mountains today, with snow levels rising up to around 2000ft. Expect 6-12" of accumulation above this level, with highest amounts in the Lutak zone. Winds will be moderate out of the SE, causing increased loading on N - NW - W aspects. Wind loaded terrain will be building tender wind slabs up to 50cm thick. The new snow will be upside-down (slabby on top and weak at the bottom) which makes for ideal soft slab avalanche conditions. Underneath the new snow, Saturday's snowfall is cold and weak so natural settling will occur as well.

Stick to the trees today, and be cautious in any openings where small avalanches can sweep you into terrain traps.

Problem #2: Persistent Slab

Location: ALL elevations, clearings in the trees, and specific slopes above treeline (mainly slopes sheltered from NW winds) where surface hoar formed last week and wasn't blown away by NW winds. 

There are patches of buried surface hoar lingering underneath last week's layer of new snow (roughly 15-45cm deep). We observed areas natural wind slab avalanches running in low-angle terrain as mellow as 25-degrees, indicating how slick this weak layer is. It's distribution is sporadic and depends on how sheltered a slope was to last week's NW winds. This dangerous weak layer will persist for several weeks or until it can be crushed and flushed out by lots of heavy snowfall. Keep this layer in mind over the next few weeks, and be sure to dig around in wind sheltered areas to look for it. Surface hoar is sneaky because it's hard to map out, but easy to trigger. Use extra caution in openings around treeline, and avoid wind-sheltered rollovers in the alpine.

Avalanche Activity

Observations from the last week found areas of D1-D2 natural windslab and storm slab avalanches on specific terrain that was wind loaded or cross-loaded, between 2500-5000ft. Some wind slabs were sliding on low-angle slopes as low as 25 degrees, and appeared to be sliding on a buried surface hoar layer 10-30cm deep. Distribution of these avalanches was limited to wind loaded areas that had been protected from strong N/NW winds.

Weather

Moderate to Heavy snow will fall over the mountains today, with snow levels rising up to around 2000ft. Expect 6-12" of accumulation above this level, with highest amounts in the Lutak zone.

   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
 49" 0" / 0.00  7" / 0.70   0 -> 2000  mod, SE 12" / 1.00    *
Flower Mountain @ treeline
 44" 0" / 0.00  5" / 0.40   0 -> 2000  mod, SE 9" / 0.80     *
Chilkat Pass @ 3,100ft
31" 0" / 0.00  5" / 0.30   0 -> 2000  mod, SE 7" / 0.50   *

( *star means meteorological estimate )

Additional Information

If you get out riding, please send in an observation!

Do a rescue practice with your partners. Always carry a beacon, shovel, and probe, and KNOW HOW TO USE THEM.

Practice good risk management, which means only expose one person at a time to slopes 30 degrees and steeper, make group communication and unanimous decision making a priority, and choose your terrain wisely: eliminating unnecessary exposure and planning out your safe zones and escape routes.