Turnagain Pass RSS

Archives
ARCHIVED - Forecasts expire after 24 hours.
Issued
Fri, November 9th, 2012 - 7:00AM
Expires
Sat, November 10th, 2012 - 7:00AM
Forecaster
Wendy Wagner
Avalanche risk The Bottom Line

Due to early season conditions, for both the snowpack and our operations, we will be issuing intermittent snow and avalanche updates until November 17th, as conditions dictate.

BOTTOM LINE
Avalanche conditions will increase this weekend as new snow and strong wind are forecast to spill over from PWS this evening through Sunday. Natural avalanches will be possible and human triggered avalanches likely. Areas of concern are all aspects and slopes over 30 degrees above ~1500′. Likelihood of triggering an avalanche will increase with new snow amount, elevation and in areas with wind loading.

This is a good weekend to dust off and open your avalanche books, replace your beacon batteries and remember how to use your rescue gear. Letting the snow do its thing as well as hopefully cover up a few more rocks may not be the worst of ideas. For anyone that does head into the mountains this weekend, terrain management will be the key for safe backcountry recreation. Keeping slope angles low and watching for obvious clues (i.e., recent avalanches, cracking and collapsing) are things to keep an eye out for.

ANNOUNCEMENTS
Don’t forget to check the photos/observations page for early season information. Also, the calendar page is filling up with free awareness classes and other avalanche education courses offered in our area.

SNOWPACK and AVALANCHE DISCUSSION
This week we have seen a lull in both the weather and avalanche activity, but with new snow and wind on the way for the weekend we can expect that to change. Storm snow instabilities within the new snow, in the form of sluffs and storm slabs, will be likely if the forecasted 10-14″ of snow verifies. These problems should settle out rather quickly, in a day, or at most 2 days.

However, the bigger story, and most concerning, is the new snow load reactivating the old October facets (see image below). It only took 6-10″ of new snow last weekend to create a very touchy slab avalanche problem. With this storm, the facets are not quite as loose as they were a week ago now that they have been buried for 5-6 days. Yet, they are still there and reactive and have the potential to produce larger avalanches this time around. If we get enough snow and wind to get them going that is. The one thing this system does have that the last one didn’t are much stronger winds. These will produce larger wind slabs that form both near (like last weekend) and well off the ridgelines (unlike last weekend).

Snowpack before the Fri-Sun (11/9-11/11) storm sets in. Main concern is faceted layer. Existing surface is generally composed of soft decomposing fragment from last storm.

Any avalanche triggered within the old Oct snow will be around 1-3′ deep and could propagate in areas that are not expected. Remote triggers (for example, triggering an avalanche on top of you from below) are possible. Hence, very conservative route finding is the ticket until this faceted layer gets enough load to either flush out with widespread avalanche activity and/or has time to adjust to the load.

Above cracking is a red light to stick to lower angle slopes, 30 degrees or under (including what is above you).

Fri, November 9th, 2012
Alpine
Above 2,500'
0 - No Rating
Avalanche risk
Treeline
1,000'-2,500'
0 - No Rating
Avalanche risk
Below Treeline
Below 1,000'
0 - No Rating
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. Dangerous avalanche conditions. 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.
Weather
Fri, November 9th, 2012

The Friday – Sunday storm system is looking to lay down somewhere between 10-14″ (storm total) of medium density snow near treeline. The rain snow line is projected near 500′. The most intense part of the storm will be Saturday. Ridgeline winds are currently blowing from the east in the low teens, gusting around 30mph, and will increase into 40’s, gusting in the 50’s or more, Saturday. Ridgeline temperatures have been increasing Friday from 20F to 24F and should level out in the mid 20’s until Sunday when colder air moves in. The system looks to abate Sunday.

CNFAIC Weather Page and the NWS forecast

Observations
Recent Observations for Turnagain Pass
Date Region Location
11/16/23 Turnagain Observation: Tincan Common
11/14/23 Turnagain Observation: Sunburst/Magnum
11/14/23 Turnagain Observation: Seattle Ridge
11/13/23 Turnagain Avalanche: Tincan Trees
11/12/23 Turnagain Observation: Sunburst
11/12/23 Turnagain Avalanche: Goldpan – avalanche
11/11/23 Turnagain Observation: Tincan Common
11/11/23 Turnagain Observation: Taylor Pass – Sunburst
11/10/23 Turnagain Observation: Tincan
11/10/23 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.