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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Tuesday, March 4th 2014
Created: Mar 4th 6:30 am
1 Low Alpine / Above 2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
1 Low Treeline / 1,000'-2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
1 Low Below Treeline / Below 1,000' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
 Show the Complete North American Avalanche Danger Scale
Special Announcement

Join CNFAIC forecasters John Fitzgerald and Wendy Wagner at REI on Thursday night from 6-7:30pm for a presentation on this season's unusual weather, snow and avalanche cycles. This talk will get into the nitty-gritty of the impressive wet avalanche cycle in late January, discuss the unique snowpack we have seen this year and more. We look forward to seeing you there. To reserve a seat go to REI's website on this link - plus, it's FREE!!


The Bottom Line

The avalanche danger remains LOW above and below treeline. Though we have light snow showers on tap this afternoon, we are only likely to see a trace to an inch accumulate in the Eastern Turnagain Arm zone. Cool temperatures and crusts will keep the snow locked into place.

In the off chance snowfall intensifies in a favored area and up to 6 inches fall by this afternoon, the danger will rise to MODERATE for loose snow avalanches and possibly shallow slabs. 

LOW danger does not mean NO danger.  While avalanche activity is unlikely today, it is important to always use good travel practices.


Primary Concern

Normal caution is advised in the backcountry today. There has been no new avalanche activity for the past 4 days. The latest activity was between February 26 and 28th when a warm-up and 0.2" of rain triggered several small wet loose avalanches and, in the periphery of the forecast zone, a few wet slab avalanches. This warm-up capped our pack with a 1-4+" inch crust and began a several day melt-freeze cycle. With cold temperatures and cloud cover today, the pack will remain locked-up and frozen.

In anticipation of snowfall this week, it's important to take inventory of the surface conditions. Above the melt-freeze crust that caps the snowpack is a healthy layer of surface hoar which formed two nights ago (photo below and more details HERE). This is an ideal weak layer/bed surface combination and something to watch for if more than just a few inches of snow accumulates in the next few days. For today however, there is not enough snow in the cards.


           Pictured below: widespread 5mm surface hoar over a crust - Todd's Run (3,600', NNW)
           

 

Additional concern to consider at upper elevations (4,000' and higher):

Persistent slabs in steep high elevation terrain on the periphery of the forecast zone and in outlying areas. We have a generally poor snowpack structure at this elevation. 1-3' below the degrading surface crusts is a weak layer of facets sitting on, and in between, the January crusts. These faceted layers have not been reactive of late but still exist. It will be remotely possible to trigger an avalanche in very steep terrain.


Mountain Weather

Yesterday's cooling temperatures, shifting winds and mid-level clouds were the first sign of a change in the weather. During the past 24-hours temperatures have averaged in the low 20's at the ridgetop weather stations and are sitting in the teens this morning. Winds have shifted from the Northwest to the Southeast overnight and continue to be light around 5mph.

A cold front is sliding down for the Northeast and joining with a weak low centered over us currently. Very light snow showers are in the forecast for today into Thursday. Only around a trace to an inch is expected by this evening. Temperatures look to remain in the teens on the ridgetops and near 30F at 1,000' (cold enough that snow might make it to sea level). Winds are expected to pick up slightly to 10-15mph from the Southeast.

Beginning late tonight and through Wednesday we should see temperatures remain just cold enough for snow to sea level with 2-5" possible. Snow should taper off Thursday. Stay tuned.

 

A few snowpack and water #'s - as of March 1st from the Turnagain Pass SNOTEL at 1880' elevation on Center Ridge:

Snow depth:  42", this is 47% of average...ouch (Only 10 years of data exist so far, 2005-2014)
Precipitation (graph below):  86% of average (due to rain in October and January)
SWE (graph below):  
50% of normal for the median SWE


          

 

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: Mar 15, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: OpenPlease park on road in and leave the turnaround (near outhouse) open for trailers to turn around.
Placer River: Open
Skookum Drainage: OpenSkookum drainage closes to motorized use on April 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: Open
Twentymile: Open
Seward District
Carter Lake: Open
Lost Lake Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Primrose Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Resurrection Pass Trail: ClosedClosed for 2016/17 winter season. This is a non-motorized season. This alternates every other year and will open again during the 2017/18 winter.
Snug Harbor: Open
South Fork Snow River Corridor: Open
Summit Lake: Open

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
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