Hatcher Pass

Forecast as of 03/28/2019 at 07:00 and expires on 03/29/2019

Above 3,500ft None

2,500 to 3,500ft None

Below 2,500ftNone

Degrees of Avalanche Danger

Problem Details

This information is a Conditions Update. Danger ratings are only issued with avalanches advisories.  The next avalanche advisory is scheduled for Saturday March 30, 2019.

Previous avalanche advisories HERE

MIDWEEK SNOW AND AVALANCHE CONDITIONS SUMMARY FOR MARCH 28, 2019

It will be possible for large cornices to fail naturally or for a human or dog to trigger today. Cornice-triggered avalanches have the potential to trigger larger sluffs or slab avalanches that may fail to the ground. Human-triggered small to large, wet loose avalanches will be possible on steep slopes (>40 degrees) on all aspects at lower elevations and on E to W aspects at mid and upper elevations, in the afternoon. Human-triggered wet slabs will be possible today on SE to SW aspects, on slopes steeper than 30 degrees, at mid and upper elevations, in the afternoon.

Several skiers have reported triggering small wet loose avalanches on steep SE to SW aspects the last few days.  Many small natural wet loose avalanches, some gouging down to ground, have been observed the last few days.  Several cornice triggered avalanches have been observed, including a large, natural cornice-triggered avalanche on a west aspect of Rae Wallace Chutes on Marmot that occurred overnight Monday the 25th.

The west side of Hatcher Pass was favored during the last round of snow Saturday night the 23rd and Sunday night the 24th. This zone has 3-6” of settled snow that is generally drier.  The East side of Hatcher Pass and Independence Mine Bowl received 3” overnight Saturday the 23rd and 1” overnight Sunday the 24th.  On the east side of Hatcher Pass, the snow is moist on most aspects and cooked down on southerly aspects.  Corn harvesting can be found on lower angle E to W slopes at mid elevations and upper elevation southerly slopes early in the day before slopes heat up. At lower elevations the snow is isothermal and snowmachines and skis will trench easily.

This report is a mid-week conditions update, so please be sure to check hpavalanche.org for advisories on Saturdays and follow the HPAC Facebook and Instagram for updates. Help us keep tabs on the Hatcher Pass area! If you see any avalanche activity send us an observation HERE. Thank you to everyone who has already submitted observations this season - you can see those HERE!

 

Corn harvesting can be found on lower angle E to W slopes at mid elevations and upper elevation southerly slopes early in the day before slopes heat up. Pictured above: a skier on Gold Cord Peak easily triggering roller balls.  Later observers triggered small wet loose sluffs skiing Gold Cord Peak in the afternoon.

 

Snowmachiners have high-marked steep slopes across Hatcher Pass without incident.  Pictured above: 4500', WNW to NW aspects near Archangel road.

 

Problem 1: Cornices

Large cornices have formed above leeward aspects and have released naturally in the last week, triggering large avalanches that have stepped down and failed to ground in places. These large cornices have proven sensitive to human and dog triggers and should be avoided. Give cornices a wide berth as they can break back much further than expected and will be possible to trigger larger avalanches below. We should avoid traveling below cornices. Low visibility can make judging the size and safe route around cornices difficult. Cornices are extremely unpredictable.

 

 

 

 

Pictured above is a natural cornice fall that triggered a large slab avalanche on a west aspect of Rae Wallace Chutes, Marmot at ~4500'. This avalanche stepped down to ground in some places and occurred overnight Monday the 25th.

 

Problem 2: Wet Loose

Human-triggered small, wet loose avalanches will be possible on steep slopes (>40 degrees) on all aspects at lower elevations and on E to W aspects at mid and upper elevations, in the afternoon.  We are right at the tipping point of seeing more frequent and larger wet avalanches, up to D2 in size. The good news: Wet loose avalanches are predictable and avoidable. Pay attention to aspects and ski and ride southerly aspects early!

Temperatures have remained unseasonably warm this week in Hatcher Pass. The last three days ridgetop temperatures have increased above freezing during the day.  While temperatures have dropped below freezing overnight at ridge tops, temperatures at mid and lower elevations have had superficial freezes. 

Pay attention to rollerballs gaining momentum, sinking in up to your shins in the snowpack, and watch for wet loose activity on other aspects and terrain. These are all great clues the wet avalanche hazard is rising and indicators that it’s time to move to shadier and less saturated slopes to travel on. We should avoid traveling over or in terrain traps, as they amplify the consequence of even a small slide.

Pictured above are several natural wet-loose avalanches reported by observers Tuesday March 26th on a SW aspect near Birthday Pass at ~4500'.

 

Problem 3: Wet Slab

Human-triggered wet slabs will be possible today on SE to SW aspects, on slopes steeper than 30 degrees, at mid and upper elevations in the afternoon.  Although we have seen few wet slabs in Hatcher Pass, we are right at the tipping point for them to occur with continuous warm temperatures. Wet slabs are becoming more and more likely  with this warming trend, particularly where the snowpack structure is shallower, and has a slab sitting on crusts over weak basal facets and depth hoar.  Wet-slabs could be up to D2 is size, or large enough to bury, injure, or kill a person. 

Paying attention to rising temperatures, and lack of overnight freezing for several nights are your best red flags for knowing when wet-slabs will occur. Stepping off your snow machine or out of your skis to see if you are sinking in past your shins is a good clue you should head to lower angle terrain or a different aspect to recreate. Wet-slabs can be remotely triggered and tests can be unreliable.

Wet slabs are unlikely at the lower elevations where the snowpack structure is mostly weak, lacking a slab component. However, wet slabs at mid elevations may run into low elevations so beware of being in run-outs under steep southerly slopes.

 

 

 

 

Avalanche Activity

Several skiers have reported triggering small wet loose avalanches on steep SE to SW aspects the last few days.  Many small natural wet loose avalanches, some gouging down to ground, have been observed the last few days.  Several cornice triggered avalanches have been observed, including a large, natural cornice-triggered avalanche on a northwest aspect of Rae Wallace Chutes on Marmot that occurred overnight Monday the 25th. For details and photos, please see observations.

 

Weather

Weather History

Weather at 3450' since Saturday 3/23:

Temperatures averaged 32°F, with a low of 25°F and a high of 43°F.

Winds averaged N 3 mph, max 6 mph.  Max gusts recorded were SE 16 mph .

There has been 4" new snow (0.3" SWE) recorded at Independence Mine since 3/23.

Weather at 4500' since Saturday 3/23:

Temperatures averaged  28°F, with a low of  22°F and a high of 40°F.

Winds averaged SE-SSE 6 mph, max 17 mph.  Gusts averaged SE 10 mph, max gust 27 mph.

Forecast Weather

Stay tuned to the NOAA point forecast for an updated weather forecast each day. The best way to see if it's snowing in Hatcher Pass is to look at the webcam snow stake HERE and the Independence Mine SNOTEL site HERE

State Parks Snow Report and Motorized Access information can be found here.

Alerts

Get the full summary HERE.

Announcements

This information is a Conditions Update. Danger ratings are only issued with avalanches advisories.  The next avalanche advisory is scheduled for Saturday March 30, 2019.

Previous avalanche advisories HERE

MIDWEEK SNOW AND AVALANCHE CONDITIONS SUMMARY FOR MARCH 28, 2019

It will be possible for large cornices to fail naturally or for a human or dog to trigger today. Cornice-triggered avalanches have the potential to trigger larger sluffs or slab avalanches that may fail to the ground. Human-triggered small to large, wet loose avalanches will be possible on steep slopes (>40 degrees) on all aspects at lower elevations and on E to W aspects at mid and upper elevations, in the afternoon. Human-triggered wet slabs will be possible today on SE to SW aspects, on slopes steeper than 30 degrees, at mid and upper elevations, in the afternoon.

Several skiers have reported triggering small wet loose avalanches on steep SE to SW aspects the last few days.  Many small natural wet loose avalanches, some gouging down to ground, have been observed the last few days.  Several cornice triggered avalanches have been observed, including a large, natural cornice-triggered avalanche on a west aspect of Rae Wallace Chutes on Marmot that occurred overnight Monday the 25th.

The west side of Hatcher Pass was favored during the last round of snow Saturday night the 23rd and Sunday night the 24th. This zone has 3-6” of settled snow that is generally drier.  The East side of Hatcher Pass and Independence Mine Bowl received 3” overnight Saturday the 23rd and 1” overnight Sunday the 24th.  On the east side of Hatcher Pass, the snow is moist on most aspects and cooked down on southerly aspects.  Corn harvesting can be found on lower angle E to W slopes at mid elevations and upper elevation southerly slopes early in the day before slopes heat up. At lower elevations the snow is isothermal and snowmachines and skis will trench easily.

Got 5 minutes? Take the short survey in the link below to help researchers at University of Alaska Southeast and Alaska Pacific University who are investigating who, how, and where Alaskans travel in the backcountry. 

https://bit.ly/2HstAM7