Hatcher Pass Avalanche Center

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ARCHIVED - Forecasts expire after 24 hours.
Thu, December 29th, 2022 - 7:00AM
Fri, December 30th, 2022 - 7:00AM
Jake Kayes
Avalanche risk The Bottom Line

The avalanche danger is MODERATE above 2500 feet. Large human-triggered Persistent Slab avalanches 2 to 4 feet deep are possible, on Southeast to West aspects, on slopes 30º and steeper. Natural avalanches are unlikely. 

At low elevations the danger is low. Below 2500 feet previous winds were less intense.

Two strong wind events with extreme gusts on December 23rd and December 25th/26th have drastically changed conditions in Hatcher Pass.

Breakable crusts, hard snow, and wind features make for difficult riding conditions. An athletic injury from poor riding quality is a real hazard today. 

Special Announcements

On Saturday, Jan 21st come join the HPAC team in celebrating the return of Bearpaw River Brewing Company’s Square Pow IPA. Stop by between 11AM-8PM, at the “Big Bear” location at 240 E Railroad Ave. in Wasilla.

Portions of the proceeds from draft pours and 4-pack sales will be donated to the Hatcher Pass Avalanche Center and Bearpaw’s full food menu will be available!

Thu, December 29th, 2022
Upper Elevation
Above 3,500'
2 - Moderate
Avalanche risk
Mid Elevation
2 - Moderate
Avalanche risk
Low Elevation
Below 2,500'
1 - Low
Avalanche risk
0 - No Rating
1 - Low
2 - Moderate
3 - Considerable
4 - High
5 - Extreme
Avalanche risk Avalanche risk Avalanche risk Avalanche risk Avalanche risk
Travel Advice Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential. Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
Likelihood of Avalanches Natural and human-triggered avalanches unlikely. Natural avalanches unlikely; human-triggered avalanches possible. Natural avalanches possible; human-triggered avalanches likely. Natural avalanches likely; human-triggered avalanches very likely. Natural and human-triggered avalanches certain.
Avalanche Size and Distribution Small avalanches in isolated areas or extreme terrain. Small avalanches in specific areas; or large avalanches in isolated areas. Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. Large avalanches in many areas; or very large avalanches in specific areas. Very large avalanches in many areas.
Recent Avalanches

No recent avalanches have been observed or reported since the last forecast on December 24th. Click here for more info.

Avalanche Problem 1
  • Persistent Slabs
    Persistent Slabs
  • Certain
    Very Likely
  • Historic (D4-5)
    Very Large (D3)
    Large (D2)
    Small (D1)
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

Likelihood of Avalanches
Terms such as "unlikely", "likely", and "certain" are used to define the scale, with the chance of triggering or observing avalanches increasing as we move up the scale. For our purposes, "Unlikely" means that few avalanches could be triggered in avalanche terrain and natural avalanches are not expected. "Certain" means that humans will be able to trigger avalanches on many slopes, and natural avalanches are expected.

Size of Avalanches
Avalanche size is defined by the largest potential avalanche, or expected range of sizes related to the problem in question. Assigned size is a qualitative estimate based on the destructive classification system and requires specialists to estimate the harm avalanches may cause to hypothetical objects located in the avalanche track (AAA 2016, CAA 2014). Under this schema, "Small" avalanches are not large enough to bury humans and are relatively harmless unless they carry people over cliffs or through trees or rocks. Moving up the scale, avalanches become "Large" enough to bury, injure, or kill people. "Very Large" avalanches may bury or destroy vehicles or houses, and "Historic" avalanches are massive events capable of altering the landscape.

Signal Word Size (D scale) Simple Descriptor
Small 1 Unlikely to bury a person
Large 2 Can bury a person
Very Large 3 Can destroy a house
Historic 4 & 5 Can destroy part or all of a village
More info at Avalanche.org

There have been two separate significant wind events in the forecast area that are worth mentioning. On December 23rd strong winds from the east lasted for 19 hours with gusts up to 71 mph. On the evening of December 25th, strong winds from the Northeast and East lasted for 15 hours with gusts up to 41mph. These wind events transported large amounts of snow at mid and upper elevations, and drastically changed the riding quality in Hatcher pass. 

Winds were much less significant on Dec 25th at lower elevations.

West Marmot 12/24.

Riding quality is extremely challenging at the moment. Breakable crusts, supportable slabs, old rain crusts and relatively soft snow can be found in a very small area. Both uphill and downhill travel are difficult at the moment.

The weak faceted snow that we’ve been talking about all season is now buried 2 to 5 feet deep with a stiff hard slab on top. Human triggered persistent slabs are possible on slopes 30º and steeper. This avalanche problem will be found above 2500 feet on Southeast thru West aspects. As the weak snow at the ground is buried deeper it will become more and more difficult to trigger an avalanche but not impossible. If you do trigger an avalanche it will be large in size, natural avalanches are unlikely.

Click here to an observation from Dec 28th for a better idea of snowpack structure.

It will be important to identify areas where the snowpack is thinner and easier for your weight to affect weak snow on the ground. Thin areas will be found at ridge lines and near rocks. The snowpack depth is highly variable depending on aspect and is anywhere from 2-5 feet deep. In some areas near ridge lines the ground is exposed. 

Snowmachines and other travelers that are capable of producing more force on the snowpack will have higher chances of triggering an avalanche.

The two wind events have created hard slabs. Hard slabs are especially difficult to manage, they will allow you to travel out onto a slope before failing above you, making escape difficult if not impossible. 

Shooting cracks and collapsing will be red flags for this problem, but may not be present before triggering an avalanche.

If you decide to brave the difficult riding conditions, be sure to use safe travel protocol in avalanche terrain:

  • SPREAD OUT when ascending.
  • Descend ONE at a time and regroup in identified safe zones.
  • Avoid riding above or near cliffs, rocks, gullies or other hazards.
  • As always, carry a transceiver, probe, and shovel, and know how to use them!

Signs of strong winds on east Skyscraper. Anti tracks, wind effected snow and sastrugi make for difficult riding conditions.

Anti tracks can be found on many slopes at the moment.

Signs of wind effected snow and previous avalanches on 12/23 in Ray Wallace Chutes.

Thu, December 29th, 2022

NWS AVG Forecast here.

NWS point forecast here.

Marmot Weather Station here.

Independence Mine Snotel here.

State Parks Snow Report and Motorized Access information here.

Recent Observations for Hatcher Pass