CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Wednesday, March 20th 2019 7:00 am by Aleph Johnston-Bloom
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
Previous ForecastNext Forecast
BROUGHT TO YOU BY
The Bottom Line

The avalanche danger will rise to HIGH today and large to very large natural avalanches will become likely. Very warm temperatures, heavy precipitation with a rising rain/snow line and strong winds will impact the region. Travel in avalanche terrain is not recommended. Avalanches have the potential to be very deep and dangerous. 

PORTAGE VALLEY:  Travel in runout zones from avalanches including venturing along and past the Byron Glacier Trail continues to be not recommended. Very large avalanches have been observed in Portage over the past few days and are expected to continue with this next round of active weather. 

SUMMIT LAKE (& INTERIOR EASTERN KENAI MTS):  Extra caution is advised. Large human triggered avalanches remain likely. Avalanches have the potential to release in old buried weak layers.

SEWARD/LOST LAKE:  New snow, rain and wind will increase avalanche danger again in this region as well. Large and dangerous natural avalanches have been observed in this area during the recent avalanche cycle. 

 


 Show the Complete North American Avalanche Danger Scale
4 High Alpine / Above 2,500' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
4 High Treeline / 1,000'-2,500' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
4 High Below Treeline / Below 1,000' Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Special Announcement
  • Turnagain Pass 20 years later: On Saturday, March 23rd from 12-2pm swing by the Turnagain Pass moto lot and meet the CNFAIC avalanche forecasters, bring and test your avalanche rescue gear and learn about the history of Turnagain Pass and the CNFAIC. We'll even have a few beacons buried so you can test your skills before heading into the hills!
  • Feeling sporty? Want to support avalanche education in Alaska? Head to the Alaska Avalanche School Ski-Mo (uphill/downhill) fundraiser race at Arctic Valley on Sunday, March 24th at 1pm. For more information click HERE. Great fun! Great cause!

Avalanche Problem 1

Storm Slabs

Almost Certain
Very Likely
Likely
Possible
Unlikely

Chance

Historic
Very Large
Large
Small

Size

Wow! Getting to see the extent of the St. Patty's Day avalanche cycle was impressive and scary. With a window of good visibility yesterday large, deep avalanches that occurred 3.17 and 3.18 were observed across the advisory area. Additionally and notably two large avalanches were observed running naturally yesterday. The Five Sisters avalanche path in Portage ran in the morning with a 10+ foot crown and a slide in Main Bowl on the back side of Seattle Ridge was observed running in the afternoon. Today the next storm system is forecast to impact the area. Temperatures are already above freezing in the Alpine, rain is expected to fall to 2500' and winds are already gusting into the 70s on Sunburst. There is a buffet of avalanche issues today and the potential for large to very avalanches makes travel in avalanche terrain including runouts not recommended. The crust that formed with cool temperatures Monday night could eventually break down and there is either colder snow that could be over loaded as it becomes saturated or at lower elevations already very saturated snow that could move. Above the rain/snow line new snow and wind will add stress to the snowpack and cornices are large and dangerous. Investigating the very large avalanche on Tincan yesterday showed that avalanches are breaking back to the March 8th new/old snow interface made up of small facets and buried surface hoar. Multiple feet of snow now rest on top of this layer and avalanches today and tomorrow may still break down at this weakness. The snowpack will need time to adjust to all the loading from the March barrage of storms. Give it some time and enjoy other activities away from the mountains! 

 

Natural avalanche in Main Bowl on the backside of Seattle Ridge observed running yesterday afternoon, 3-19-19. Photo: Travis Smith 

Five Sisters avalanche path in Portage Valley was observed running yesterday morning, 3-19-19.  

 

The 3.18.19 Tincan avalanche. Photo from Seattle Ridge: Travis Smith. 


Mountain Weather

Yesterday: Partly sunny with temperatures in the 20Fs to 40Fs depending on elevation. Winds were light and easterly. Clouds moved in overnight and temperatures were in the 30Fs and 40Fs. Easterly winds increased blowing 30-40 mph with gusts into the 70s. 

Today: Rain and snow throughout the day with close to an inch of water in the forecast. Rain/snowline is expected to be around 2500'. Temperatures will be in the high 30Fs to high 40Fs, with Alpine temperatures already in the mid 30Fs. Winds will be easterly 30-40 mph with gusts into the 60s and 70s. Rain and snow continue overnight with unseasonably warm temperatures and strong winds. 

Tomorrow: The warm wet weather continues into Thursday. Expect more of the same. This active pattern extends into the weekend with a brief break on Saturday and another storm Sunday. 

*Seattle wind sensor was cleared and started reporting 4 pm yesterday, data is incomplete.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880') 36  0.1  86 
Summit Lake (1400')  35   29 
Alyeska Mid (1700')  35   0.08  76 

 

RIDGETOP 24-hour data (6am - 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812') 24   NE  18  78
Seattle Ridge(2400') 30    SE*    4*      24* 

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).

Winter snowmachine use open/closed status and riding conditions updates

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: May 06, 2019 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: ClosedClosed as of 4.3.19
Placer River: ClosedClosed as of 3.20.19 due to lack of snow.
Skookum Drainage: ClosedPlacer access closed as of 3.20.19 due to lack of snow.
Turnagain Pass: ClosedClosed as of 5/6. Thanks for a great season all, see you next winter!
Twentymile: ClosedClosed as of 3.20.19 due to lack of snow.
Seward District
Carter Lake: Closed
Lost Lake Trail: ClosedClosed as of 3.22.19 due to lack of snow
Primrose Trail: ClosedClosed as of 4.3.19 due to lack of snow
Resurrection Pass Trail: ClosedClosed for the 2018/19 season. Next season will be open to motorized use.
Snug Harbor: ClosedClose as of 5.1.2019
South Fork Snow River Corridor: ClosedClosed as of 3.20.19 due to lack of snow.
Summit Lake: Closed

Subscribe to the Turnagain Area Avalanche Advisory:

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur. This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.


USFS SNOW AND AVALANCHE HOTLINE (907) 754-2369
If you have comments or questions regarding CNFAIC operations or winter recreation management, please email staff@chugachavalanche.org
© 2019 Chugach National Forest Avalanche Information Center. All rights reserved.
FCNFAIC