Turnagain Pass Avalanche Forecast RSS

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ARCHIVED FORECAST - All forecasts expire after 24 hours from the posting date/time.
Issued
Mon, March 4th, 2019 - 7:00AM
Expires
Tue, March 5th, 2019 - 7:00AM
Forecaster
Aleph Johnston-Bloom
The Bottom Line

A generally  LOW  avalanche danger remains for Turnagain, Girdwood and Portage areas. Although triggering a slab avalanche is unlikely, watch for sluffs on steep shaded slopes. Avoid travel under glide cracks and give cornices a wide berth.

SUMMIT LAKE / SILVERTIP:   More caution is advised south of Turnagain Pass as the snowpack is thin and harbors old weak layers.  

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Mon, March 4th, 2019
Alpine
Above 2,500'
Low (1)
Avalanche risk
Treeline
1,000'-2,500'
Low (1)
Avalanche risk
Below Treeline
Below 1,000'
Low (1)
Avalanche risk
Alpine
Above 2,500'
Avalanche risk
Low (1)
Treeline
1,000'-2,500'
Avalanche risk
Low (1)
Below Treeline
Below 1,000'
Avalanche risk
Low (1)
Danger Scale:
No Rating (0)
Low (1)
Moderate (2)
Considerable (3)
High (4)
Extreme (5)
Avalanche Problem 1
  • Normal Caution
    Normal Caution
Normal Caution
Normal Caution means triggering an avalanche is unlikely but not impossible.
More info at Avalanche.org

Today will be another day of Normal Caution (LOW danger). Clearing skies, temperatures generally in the 20Fs and calm winds should not have much impact on avalanche hazard.  With afternoon sunshine and as valley temperatures rise above freezing, low elevation solar aspects may see a little surface heating. 

“Don’t mess with the brown frown!” i.eavoid travel under glide cracks. Late last week and into the weekend we saw several glide cracks release into avalanches in the Girdwood Valley and at Turnagain Pass. Although many of these slides are on the smaller side and in areas not commonly traveled, one released Friday, March 1st on Seattle Ridge. As far as the older glide cracks we’ve been monitoring in popular areas such as Magnum, Lipps, Cornbiscuit, these do not appear to be moving as quickly. PSA: Help us keep track of these cracks and send us a photo! 

Things to keep in mind if you are headed into the backcountry:

  • Glide avalanches – These types of avalanches are highly unpredictable and not associated with human triggers. It’s always best to watch for and limit exposure under glide cracks.
  • Dry-loose sluffs – Watch your sluff on steep shaded slopes.
  • Cornice falls – As always, give cornices a wide berth. 
  • An outlier slab avalanche – Although it is unlikely a person could trigger a slab avalanche, the mountains can harbor surprises, especially in thin snowpack areas. Considering the consequences before entering into high consequence terrain and maintaining good travel protocol are good habits to keep on LOW danger days.

Surface conditions? A stout sun crust has been found on southerly facing slopes. Otherwise, 4-8″ or so of soft re-crystalized (near surface faceted snow) sits over a firmer base on shaded aspects and some sastrugi, old wind crust and/or rime crust can be found along ridgelines. In anticipation of the next storm, we are closely mapping the surface conditions as well as watching for new surface hoar growth. 

Sun crusts on Sunburst, 3-3-19. Photo: Allen Dahl

Closer view of the Seattle Ridge glide avalanche that occurred on March 1st and glide cracks to the right, 3-3-19. Photo: Allen Dahl

 

Additional Concern
  • Persistent Slabs
    Persistent Slabs
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.
More info at Avalanche.org

South of Turnagain – Summit Lake and Silvertip zones:  For anyone traveling in this area note that a shallow snowpack with a generally poor structure exists. A variety of old weak layers (facets and buried surface hoar) sit in the mid and base of the snowpack. It is uncertain as to how reactive these layers are at this point and if they could produce a slab avalanche. Assessing the slab as well as the weak layer is important. The most suspect place to trigger an avalanche is steep terrain with old, hard wind slabs sitting on weak snow. 

Weather
Mon, March 4th, 2019

Yesterday:  Broken sky cover with a few flurries and some patches of sunshine. Temperatures ranged from the teens and 20Fs to the low 30Fs depending on elevation. Winds were very light and westerly. Skies were cloudy overnight with slightly cooler temperatures and light winds.    

Today:  Mostly cloudy skies becoming partly sunny by the afternoon. Temperatures in the 20Fs at upper elevations and the low 30Fs near sea level with calm winds. Skies will become cloudy again overnight and winds will be light with temperatures in the 20Fs.

Tomorrow: Mostly cloudy skies with a chance of snow showers, temperatures in the 20Fs and light easterly winds. We are still anticipating an overall pattern change and a storm this weekend. Stay tuned for details!  

MORE STATE OF THE SNOWPACK:   March 1st Snow Depth chart for Turnagain Pass. Time to do the Low-pressure  snow dance… Remember that’s counter clockwise!

PRECIPITATION 24-hour data (6am – 6am)

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′)  26 0   0   58  
Summit Lake (1400′)  23 0    0      28    
Alyeska Mid (1700′)  26  0      0      53    

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′)  17  W  1 5  
Seattle Ridge (2400′)  24  W   1   6  
Observations
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Riding Areas
Updated Mon, December 02nd, 2019

Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: mailroom_r10_chugach@fs.fed.us

Area Status Weather & Riding Conditions
Glacier District
Johnson Pass
Closed
Closed.
Placer River
Closed
Closed.
Skookum Drainage
Closed
Closed.
Turnagain Pass
Closed
Closed.
Twentymile
Closed
Closed.
Seward District
Carter Lake
Closed
Closed.
Lost Lake Trail
Closed
Closed.
Primrose Trail
Closed
Closed.
Resurrection Pass Trail
Closed
Closed. Will be open for the 2019/20 season pending adequate snow cover.
Snug Harbor
Closed
Closed.
South Fork Snow River Corridor
Closed
Closed.
Summit Lake
Closed
Closed.

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