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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   CNFAIC Staff  
Tuesday, January 18th 2011
Created: Jan 18th 6:45 am
2 Moderate Alpine / Above 2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
2 Moderate Treeline / 1,000'-2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
2 Moderate Below Treeline / Below 1,000' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
 Show the Complete North American Avalanche Danger Scale
The Bottom Line
Good morning backcountry travelers this is Lisa Portune with the Chugach National Forest Avalanche Information Center on Tuesday, January 18th at 7am. This will serve as 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).

ANNOUNCEMENTS
We are starting an incentive program to encourage everyone to submit snow and avalanche observations. Each quality observation will earn you one chance to win a monthly $100 gift certificate. At the end of this season all the submissions will go into a drawing for an avalanche beacon of your choice. Thanks for all the great work, and keep sending in those observations!

BOTTOM LINE
The avalanche danger rating remains at MODERATE today. While the likelihood of triggering an avalanche continues to decline, areas of instability still exist. Human triggered avalanches are still possible if you look hard enough. Predicting where you could trigger an avalanche is especially tricky right now, so use good travel techniques to minimize your exposure. Our persistent weak layers consist of numerous layers of buried surface hoar that formed in December and facets above and below the Thanksgiving Rain Crust. Unpredictable hard windslab over weak faceted snow also exists near ridgetops and in crossloaded terrain.

AVALANCHE DISCUSSION
It has been 13 days since our last snowfall and 5 days since the last reported human triggered avalanche. While all signs point to a stable snowpack, folks are still finding areas of instability and backing off of skiing and riding steep slopes. The poor structure of our snowpack still demands cautionespecially in steep high-consequence terrain. This past weekend several groups turned around and descended via their skin tracks after finding unstable faceted snow in higher elevation windloaded terrain. CNFAIC Staff groups found nothing alarming in their snowpit stability tests that kept them from their planned routes.

Persistent weak layers and hard windslab are difficult-to-manage hazards. Slope cuts are generally not effective with these types of instabilities because they tend to break above and around you. Plus you have to find just the right spot to trigger the whole thing...usually a hard-to-recognize shallow area in the snowpack. Storm snow and softslab instabilities, on the CNFAIC Staff hand, tend to break right under your sled, board, or skis and are more of a manageable hazard.

We might as well start talking about the GIANT surface hoar thats been forming the last two weeks since snow is in the forecast tomorrow. One group reported sizeable surface hoar sluffs on steeper low elevation terrain where the crystals are 4 inches in size. These palm-size feathery crystals are widespread below 1500 feet elevation and get smaller in size the higher you go. At 3000 feet the crystals are a mere two millimeters in size. Regardless, if this stuff survives before it gets buried by the next snowfall, it will be a formidable weak layer.

486-funhogsurfacehoar2.jpg

Photo by Bob Sutherland

Encyclopedia of terms: www.fsavalanche.org/Encyclopedia.aspx

WEATHER ROUNDUP
It has been 13 days since our last snowfall. Yesterday ridgetop winds averaged 5-10mph out of the east on Sunburst and 10-20mph out of the southeast on Seattle Ridge. Temps have gradually warmed up to around 10F at the higher elevations this morning but have cooled back down to the single digits at the mid and lower elevations. Ridgetop winds are light this morning at all locations. Skies are currently cloudy but are expected to clear up today from weak upper ridging. Ridgetop winds should remain in the 5-10mph range with mountain temps in the single digits. Looks like snow is in the forecast tomorrow finally!

I will issue the next advisory tomorrow morning at 7am. If you get out in the backcountry give us a call at 754-2369 or send us your observations using the button at the top of this page. Thanks and have a great day.

The NWS weather forecast for:
WESTERN PRINCE WILLIAM SOUND-
INCLUDING...WHITTIER...SEWARD...GIRDWOOD...MOOSE PASS

500 AM AKST TUE JAN 18 2011

.TODAY...PARTLY CLOUDY IN THE MORNING THEN BECOMING SUNNY.
HIGHS ZERO TO 10 ABOVE EXCEPT 15 TO 20 ALONG THE COAST.
VARIABLE WIND 10 MPH. NEAR SEWARD...NORTH WIND 20 TO 35 MPH
DECREASING TO 15 MPH IN THE AFTERNOON. NEAR WHITTIER...WEST
WIND 15 TO 30 MPH WITH GUSTS TO 40 MPH.
.TONIGHT...CLEAR IN THE EVENING...THEN INCREASING CLOUDS AFTER
MIDNIGHT WITH A CHANCE OF SNOW SHOWERS ALONG THE COAST. LOWS
10 BELOW TO 5 ABOVE EXCEPT 10 TO 15 ALONG THE COAST. VARIABLE
WIND TO 10 MPH.
.WEDNESDAY...SNOW. SNOW ACCUMULATION UP TO 3 INCHES. HIGHS
15 TO 30...WARMEST ALONG THE COAST. NORTH TO EAST WIND
10 TO 20 MPH EXCEPT NORTH 15 TO 30 MPH NEAR SEWARD.

TEMPERATURE / PRECIPITATION

SEWARD 18 9 28 / 0 60 90
GIRDWOOD 9 5 23 / 0 20 80

WEATHER STATION SUMMARY for Turnagain Pass:
-3800 Sunburst Wx Station-
recorded winds averaging 1-10mph out of the east the last 24 hours. Temps have been gradually climbing from a low of 2F yesterday morning to the current temp of 9F.
-2600 Seattle Ridge Wx Station-
recorded winds averaging 15-20mph out of the southeast for 10 hours yesterday. Temps have been creeping up from a low of 3F yesterday morning to the current temp of 9F. Winds are currently light.
-1800 Center Ridge Wx Station-
recorded no new snow the last 13 days. Temps increased from 2F to 12F yesterday but have cooled off again this morning to 3F.

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 28, 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: OpenPlacer remains open but SKOOKUM DRAINAGE will close to motorized use on April 1st.
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

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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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