Haines Avalanche Center

Forecast Expired - 11/19/2021

Above 2,500ftConsiderable

1,500 to 2,500ftModerate

Below 1,500ftLow

The Avy Rose shows the forecasted danger by elevation and aspect.

It adds more detail about where you are likely to find the dangers mentioned in the forecast. The inner circle shows upper elevations (mountain top), the second circle is middle elevations, and the outer circle represents lower elevations.

Think of the Rose as a birds-eye view of a mountain, looking down from above. The rose allows our forecasters to visually show you which parts of the mountain they are most concerned about.

WNWNNEESESSW

Degrees of Avalanche Danger

Low
Moderate
Considerable
High
Extreme

Avalanche Problems

Problem 1

Persistent Slab:

 

Confidence: Low-Moderate

Elevation: From 2,500ft to 4,000ft

Our alpine snowpack in all zones contains one or more rain crusts from mid October. Weak facetted snow has formed above and below the crust, and has been found to be quite sensitive to the weight of our new snow. Any steep, open pockets of snowpack will be ripe to avalanche on this layer, about 30-60cm deep. We expect this October rain crust will be a lasting problem as we go into winter so keep your guard up! This layer exists on all aspects, but observations are limited and uncertainty is high.

 

What is the best way to manage this risk? We can simply avoid alpine terrain that is about 30 degrees and steeper. Be aware that venturing on these steeper alpine slopes is relatively high risk currently. Persistent slabs require a wide safety buffer.

Another way to reduce your exposure to these deep weak layers would be to stick to areas of deeper snowpack (>1m deep). But be wary of hidden rocks that can act as trigger points, and thin areas around the margins of a slab.

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Wind Slab:

NW winds are howling 20-30mph. As these winds drift the new snow around, they create new wind slabs beneath any ridges and terrain features. Expect these new wind slabs to be sensitive to human triggering. High SE aspects will be the most wind-loaded and the most prone to human and natural avalanches. Human triggered avalanches will be likely today in wind loaded alpine terrain.

 

Likelihood:

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

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Weather

October brought in heavy snow in the alpine, followed by a few rain/sun crusts. November was mostly dry until mid month, when 24-30″ of snow fell.

Friday and Saturday will bring in clearing skies and strong Northwest winds. Temperatures in the alpine will be cold! Barely reaching the single digits Fahrenheit. Wind chills may be brutal. The next storm is on tap for Saturday night-Monday when 6-12″ of new snow is likely.

 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   30″  1″ / 0.10* 15″ / 1.50*   0′  strong, N 0″ / 0.00*
Flower Mountain @ treeline  40″  1″ / 0.10 14″ / 1.40  0′ strong, NW 0″ / 0.00*
Chilkat Pass @ 3,100ft  26″  5″ / 0.30 7″ / 0.40  0′ strong, NW 0″ / 0.00*

( *star means meteorological estimate )

Additional Information

In November, onX Backcountry is donating $10 of every membership to support forecasting. By leveraging their Slope Angle and Avalanche Forecast layers you’ll have access to the tools that help  inform safer backcountry travel this year.

 

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

Click the –Full Forecast– button below for more details. We need your observations! Forecasts will be issued every THU, FRI, SAT, SUN.