Hatcher Pass Avalanche Center
Hatcher Pass

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ARCHIVED - Forecasts expire after 24 hours.
Issued
Thu, January 13th, 2022 - 7:00AM
Expires
Fri, January 14th, 2022 - 7:00AM
Forecaster
Jake Kayes
Avalanche risk The Bottom Line

Small human triggered wind slabs are possible at upper elevations. Wind slabs will be found on West thru East aspects. Natural avalanches are unlikely.

Persistent slab avalanches are unlikely but still possible in isolated locations at mid and upper elevations, on SE thru SW aspects. These avalanches will be small to large in size.

On Jan 11th 3-4” of new snow fell in Hatcher Pass.

Special Announcements
Join the forecasters today from 4-5pm at the Hatcher Pass Lodge for our first “Forecaster Chat.” Come hear what we have to say about the snowpack and check out our new swag!
Come join us Saturday Feb 5th at 6:30-10:00pm for the annual Cabin Fever Reliever. Our annual fundraiser will take place at the Palmer Train Depot. There will be food, beverages, and live music by Melissa Mitchell with Hope Social Club lite! Click here to buy tickets.
Thu, January 13th, 2022
Upper Elevation
Above 3,500'
2 - Moderate
Avalanche risk
Mid Elevation
2,500'-3,500'
1 - Low
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

Small human triggered wind slabs were observed on Eldorado Bowl on Jan 12th.

Avalanche Problem 1
  • Wind Slabs
    Wind Slabs
  • Certain
    Very Likely
    Likely
    Possible
    Unlikely
    Likelihood
  • Historic (D4-5)
    Very Large (D3)
    Large (D2)
    Small (D1)
    Size
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
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

On Jan 12-13th sustained winds from the ESE-SE were able to transport 3-4” new snow that fell on Jan 11th and create wind slabs. Wind speeds averaged 14mph with gusts up to 25mph and lasted for 24 hours. New formed slabs will be 3-6” thick on West thru East aspects, near ridge lines and on cross loaded gullies. Small human triggered avalanches are possible, natural avalanches are unlikely. Wind slab hazard will increase in the afternoon/evening as winds build through the day.

To identify this avalanche problem look for smooth wind drifted snow near ridge lines and cross loaded gullies. Use hand pits and poles/probes to help you identify dense wind affected snow, sitting on top of low density snow. Shooting cracks and whumps will be red flags for this avalanche problem. 

Riding quality has improved dramatically with the 3-4” of new snow that fell on Jan 11th. Use low risk travel techniques if you choose to head out into the backcountry today. Space out when ascending slopes, descend slopes one at a time, and regroup out of harm’s way. Know what’s below you and avoid traveling above terrain traps.

Small human triggered wind slab. Eldorado Bowl North 4200′

Look for smooth wind drifted snow near gullies and ridge lines.

Avalanche Problem 2
  • Persistent Slabs
    Persistent Slabs
  • Certain
    Very Likely
    Likely
    Possible
    Unlikely
    Likelihood
  • Historic (D4-5)
    Very Large (D3)
    Large (D2)
    Small (D1)
    Size
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

Human triggered persistent slab avalanches are possible in isolated areas at upper and mid elevations, on SE thru SW aspects. These avalanches will be small to large in size, natural avalanches are unlikely. The structure of the snowpack is poor with a stiff hard slab, sitting on top of weak sugary snow in isolated areas. The last persistent avalanche reported occurred at some point during the Bora wind event on Jan1-2nd. Click here for more info. The snowpack has gained some stability over time but a small to large persistent slab avalanche isn’t out of the question. 

To identify this avalanche problem use poles/probes to look for stiff hard snow sitting above weak sugary facets. Identifying the structure of the snowpack will be more useful than performing formal stability tests. It will be possible to trigger an avalanche without prior observing whumps and shooting cracks.

 

Weather
Thu, January 13th, 2022

NWS AVG Forecast here.

NWS Rec Forecast here.

NWS point forecast here.

State Parks Snow Report and Motorized Access information here.

Observations
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