Saturday, March 26th 2016 5:21 am by Wendy Wagner
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
A CONSIDERABLE avalanche danger remains at the mid-elevations on all aspects for glide avalanches in the Turnagain Pass, Girdwood Valley, Summit Lake and surrounding mountains. Glide cracks continue to release and produce large and destructive slides. Avoiding time under glide cracks is recommended.
At the upper elevations (above 3,000') there is a MODERATE avalanche danger where shallow wind slabs 6-8" thick may be found and possible to trigger. Watch for, and limit time under, cornices which are large and looming along ridgelines. Last, the sun may warm the surface enough for human triggered wet loose avalanches on southerly aspects.
*If you are headed to the Summit Lake area don't forget to check this morning's Summit Lake Summary.
|Show the Complete North American Avalanche Danger Scale|
|Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.|
|Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.|
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Making plans for Arctic Man 2016? Don't forget your beacon, shovel and probe! CNFAIC will be there all week and offering two FREE companion rescue workshops. Click HERE for more info. We hope to see you there!
The snowpack continues to fall apart at the ground. Yesterday, another large glide crack released on the face of Seattle Ridge. If you are headed to Turnagain Pass this weekend you can't miss it, it's front and center, just across from the motorized parking lot. If you have not been to the 'Pass' for a while, you may be surprised at how many cracks litter the mid-elevations and how many of these have released. It goes without saying, staying out from under glide cracks is HIGHLY recommended!
*With the unseasonably warm temperatures over the past week, the springtime melt-down (or shed-cycle) is closing in upon us. We do have cooler temperatures for today, and likely tonight, that will form surface crusts as high as 2,500', but it is good to remember that undreneath the pack is very wet and unsupportable at these mid-elevations. This 'rotten' soft snow, so to speak, is a red flag for not only the glide problem but for the potential for large wet slab and wet loose avalanches.
Wet Loose Slides today? Southerly slopes seing direct sunlight may warm enough to melt the surface crust. In this case, wet loose slides could be triggered by people. Keep tabs on the surface conditions.
At elevations above 3,000' (above the majority of the glide crack/avalanche hazard) fairly dry snow exists. There was roughly 2-5" of new snow yesterday which sits on a mixture of old loose snow and old sun and wind crusts. Shallow wind slabs composed of mostly the new snow likely formed on leeward slopes during yesterday's moderate Easterly winds. These slabs should be ~6-8" thick and in pockets along ridgelines. Quick hand pits and watching the surface texture for smooth rounded wind pillows and drifts will help to find any relatively new wind slabs.
With a chance for direct sunshine today (and tomorrow) watch for cornices to weaken and possibly fall naturally. We have not seen much cornice failure recently but we do know these large features will begin to start calving soon. Limiting and avoiding time under cornices will be key as we head into springtime hazards.
If skies clear for travel above treeline, take stock of the slope or couloir you wish to ride/ski - is there a large cornice looming over you while you ascend/descend?
Yesterday's weather consisted of overcast skies with some light precipitation in the morning hours. Around .5" of rain fell up to 2,000' and between 2-5" of snow fell above 2,000'. Ridgetop winds were moderate, averaging to 20mph with gusts to 40mph from a generally East direction. Temperatures were in the mid-30's at 1,000' and upper 20's at 3,000'. Overnight, winds have died down substantially and temperatures have cooled off several degrees and move into a break between storms.
For today, we are expecting partly cloudy skies, which could become quite clear by noon before a chance more clouds might move in later today (tough sky cover forecast). No precipitation is expected and winds are slated to be light to moderate from a Northerly direction, averaging 5-15mph. Temperatures should begin to climb again today as the sun comes out and reach up to 40F at 1,000'.
Sunday looks to be nice: mostly clear skies and light Northerly winds as a quick high pressure ridge builds before another low pressure system moves in Sunday night.
PRECIPITATION 24-hour data (6am - 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880')||32||rain||0.5||124|
|Summit Lake (1400')||35||rain||0.3||41|
|Alyeska Mid (1700')||33||rain||0.3||105|
RIDGETOP 24-hour data (6am - 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).
Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.
(Updated: Apr 22, 2018 )
|AREA||STATUS||WEATHER AND RIDING CONDITIONS|
|Johnson Pass:||Closed||Closed as of April 20th|
|Placer River:||Closed||Closed as of April 17th|
|Skookum Drainage:||Closed||Closed as of April 1st.|
|Twentymile:||Closed||Closed as of April 13th|
|Lost Lake Trail:||Closed||Closed as of April 13th|
|Primrose Trail:||Closed||Closed as of April 13th|
|Resurrection Pass Trail:||Closed||Closed as of April 20th|
|South Fork Snow River Corridor:||Closed||Closed as of April 13th|
|Summit Lake:||Closed||Closed as of April 20th|
SNOW AND AVALANCHE HOTLINE (907) 754-2369
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© 2018 Chugach National Forest Avalanche Information Center. All rights reserved.