Haines Avalanche Center

Forecast Expired - 04/17/2021

Above 2,500ftHigh

1,500 to 2,500ftHigh

Below 1,500ftHigh

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Wet Avalanches:

Confidence: High.     Distribution: Widespread on solar aspects, isolated on shaded aspects.   Sensitivity: Reactive.

 

In addition to the new/old snow interface, our snowpack contains several rain/sun crusts, and a few old weak layers that will continue to weaken as the snowpack becomes warmer, softer, wetter, and weaker. All this heat and sun will cause water to percolate through the snowpack and run along crusts, which lubricates the layer. Natural and Human-caused wet slides are quite likely this weekend in terrain steeper than 30 degrees. Some of these slides will be deep and destructive.

 

If you travel in the mountains, do so in the early morning, before the snowpack heats up. When the snow softens to ankle-deep, it’s time to move to safer slopes. Keep an eye on the weather stations. If we do not get a solid freeze overnight, expect increased wet slide activity and high danger the next morning. Rocky areas will be common places for wet slides to be triggered.

 

Even small wet slides can easily entrain a person and carry them into a terrain trap.

 

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Falling Cornice:

With all this sunshine, record warmth, and a whole winter’s worth of cornices built up, you should expect any snow ledges or cornices to be dangerous right now. Stay WAY back from these monsters, which are common along ridgelines and summits. Stay out from underneath any slopes that have cornices hanging overhead. They may collapse on their own at any time, or be triggered by human weight on top.

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Weather

The big story this week is drastically warmer weather (record heat) that has moved into the area Thursday and will only increase through Tuesday. High temps will reach upper 50’s in the valleys, and 40’s in the mountains. Low temps in the mountains will be right around freezing. So overnight freezes look thin at best in most places. Solar radiation will be strong.

 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   130″+*  0″ / 0.00* 0″ / 0.00*   0′  mod, NW 0″ / 0.00*
Flower Mountain @ treeline  100″  0″ / 0.00 0″ / 0.00*  0′ mod, NW 0″ / 0.00*
Chilkat Pass @ 3,100ft  54″  0″ / 0.00 0″ / 0.00*  0′ mod, NW 0″ / 0.00*

( *star means meteorological estimate )

—The Mt. Ripinsky weather station is completely buried and no longer reporting.—

Additional Information

Practice like you play. Make sure all your rescue gear is fully functional and your beacon has full 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

With record warmth coming in this weekend, backcountry avalanche danger will be HIGH due to wet slabs, loose-wet, and falling cornices. Also expect to see falling ice/debris shed in steep terrain. Click the + Full Forecast link below for each zone to read more. Submit and read local observations below.