Turnagain Pass RSS

Archives
ARCHIVED - Forecasts expire after 24 hours.
Issued
Sun, December 25th, 2016 - 7:00AM
Expires
Mon, December 26th, 2016 - 7:00AM
Forecaster
Wendy Wagner
Avalanche risk The Bottom Line

A BACKCOUNTRY AVALANCHE WARNING has been issued through the National Weather Service for the Turnagain Pass area and surrounding mountains.  

Heavy snowfall and strong winds have created a HIGH avalanche danger in the mountains surrounding Turnagain Pass, Girdwood Valley, Portage Valley and areas on the Kenai seeing heavy snowfall. Dangerous avalanche conditions are expected on all slopes 30 degrees and steeper – including runout zones. Avalanches are expected to release naturally, be easily triggered by people and could run to elevations below 1,000′.  

Travel in avalanche terrain is NOT recommended. Today is a day to hunker down, unwrap presents, hit the slopes at Alyeska or your local ski hill/trails or get your snowmachine ready for a possible motorized opening soon!    

Special Announcements

***Carter Lake and Snug Harbor areas are open to motorized use. Please respect other closures across the Forest. The Forest Service is monitoring this storm and will open more areas as soon as there is enough snow to prevent resource damage to underlying vegetation. The Forest thanks you for your patience!

Sun, December 25th, 2016
Alpine
Above 2,500'
4 - High
Avalanche risk
Treeline
1,000'-2,500'
4 - High
Avalanche risk
Below Treeline
Below 1,000'
3 - Considerable
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.
Avalanche Problem 1
  • Storm Slabs
    Storm Slabs
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
More info at Avalanche.org

All I want for Christmas is a big snow storm
A big snow storm
Just, a big snow storm…

Merry Christmas riders and skiers!!! It seems as though Santa has answered our wishes and brought us a long awaited ‘Chugach Storm’! Yes, it’s raining at sea level, but above 500′ there is sticky new snow blanketing the mountains. Unfortunately, this is too much to play with today as by this afternoon we could be up to 20+” of new snow in 24 hours. 

STORM TOTALS in the upper elevations so far:

Turnagain Pass:     12″ and counting
Girdwood Valley:    12″ and counting
Summit Lake:          2-4″  

EXPECTED AVALANCHE ACTIVITY:  This is a text-book “rapid loading event”. Not only is 2′ of snow in 24 hours an avalanche maker in itself, this snow is falling on a VERY weak surface. The loose faceted snow combined with surface hoar (that we’ve been skiing/riding on the past several days) will act like ball bearings and inhibit the new snow from sticking to the mountainsides. Hence, widespread natural slab avalanches up to 2′ thick are likely and human triggered avalanches very likely. Winds should stay strong along with the snowfall through tonight and wind loaded slopes could harbor slabs as thick as 4′. 

Treed areas such as the Tincan Trees:  Storm snow slab avalanches 1-2′ thick are likely to be triggered in the trees. The new snow is denser than the underlying old snow – creating an upside down and unstable snowpack. Avoiding slopes over 30 degrees in treed areas is also recommended.
 

Check out the Turnagain Pass Snowstake loop at the RWIS DOT station. Thanks to the DOT for getting this station up and running for the winter!

 

Weather
Sun, December 25th, 2016

During the past 24-hours we have seen the start to our ‘Christmas Storm’. Snow began falling at noon yesterday and totals up to 6am this morning are above and in the table below. Winds ramped up dramatically yesterday morning from the East and have remained in the 30’s mph with gusts over 60mph on the ridgetops. We have limited wind data with the Sunburst weather station down, but it’s no question the winds are very strong with this system. Temperatures have warmed from the teens to the mid-20’sF above the trees and into the low 30’sF at 1,000′. The rain/snow line looks to be hovering near 500′.  

We are expecting another 10-12″ of snowfall today with around 1″ of water equivalent. Winds are expected to remain strong from the East in the 30’s mph with gusts to 75mph on the ridgetops. Temperatures look to stay warm with a rain/snow line remaining around 500′.

Tonight and tomorrow the system slowly moves out and we should see instability showers adding another few inches along with cooler temperatures.  

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 27   12   0.8   36  
Summit Lake (1400′) 30   2   0.2   9  
Alyeska Mid (1700′) 28   8   0.7   24  

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) Under repair     Under repair     Under repair     Under repair    
Seattle Ridge (2400′) 22   SE   29 60  
Observations
Recent Observations for Turnagain Pass
Date Region Location
02/24/24 Turnagain Observation: TinCan Backdoor/ Center Ridge
02/22/24 Turnagain Avalanche: Lynx Creek
02/22/24 Turnagain Observation: Turnagain, Seattle, Mt Ascension
02/21/24 Turnagain Observation: Tincan Trees
02/21/24 Turnagain Observation: Sunburst
02/20/24 Turnagain Avalanche: Tincan
02/20/24 Turnagain Observation: Seward Highway across from Johnson Pass TH
02/19/24 Turnagain Avalanche: Base of Seattle Ridge
02/18/24 Turnagain Observation: Lynx creek
02/18/24 Turnagain Observation: Tincan Trees
Riding Areas

The riding areas page has moved. Please click here & update your bookmarks.


Subscribe to Turnagain Pass
Avalanche Forecast by Email

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.