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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Saturday, April 9th 2011
Created: Apr 9th 6:47 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 Hoarding Marmot
The Bottom Line
Good morning backcountry travelers. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Saturday, April 9th 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
Congratulations to Christopher Dunaway for winning the March observer drawing. Thank you Chris, and everyone else, for sending in observations to us!

BOTTOM LINE
Today the avalanche danger is MODERATE with pockets of CONSIDERABLE for persistent slab and wind slab avalanches on slopes steeper than 35 degrees. These can be found where lingering persistent weak layers lie 1-5 deep and on any wind loaded slope. Solid snow assessment skills are necessary for travel in steep terrain today. Also, there is a MODERATE danger for wet loose snow avalanches during the afternoon on southerly slopes as the snow warms up throughout the day.

AVALANCHE DISCUSSION
Several soft slab avalanches were human triggered in the backcountry yesterday. All reports, except one possibly breaking in a persistent weak layer, were wind slabs and soft slabs formed in the most recent storm snow from Thursday, April 7th. These were 30 200 wide and 6 to over 2 deep depending on the amount of wind loading. Several older natural avalanches that occurred during the natural cycle on April 7th were just visible under windblown snow. It seems that many slopes have avalanched in the past week, helping to wipe out deeper weak layers, but the recent snow and winds have made this difficult to determine.

There are two primary concerns for today:
Persistent slab avalanches. These are in scattered locations at the mid to upper elevations, on all aspects and could break above you. They are most likely and dangerous on steeper slopes that have not avalanched during the past week where they can still be hanging in the balance. Solid snow assessment skills are necessary for ramping up the slope angle today. This means looking for and testing potential buried weak layers under the most recent storm snow.

Wind slabs. These are most prone on any wind loaded slope over 35 degrees. Rollovers, cross loaded gullies and ridgelines are the most suspect. These lingering wind slabs should begin to gain strength but I would expect people could still pop these out again today. Watch out for smooth snow surfaces, hollow feeling snow or shooting cracks from your sled or board(s).

If the sun stays out today and wind remain calm, keep an eye out for the snow to become saturated and being to sluff on southerly slopes. It will likely be easy to initiate human triggered wet sluffing which could entrain quite a bit of snow and run far on the underlying crusts.

Outside of our advisory area:
There was a dog triggered avalanche in the Eagle River area on a wind loaded slope. Details HERE.

Encyclopedia of avalanche terms.

WEATHER ROUNDUP
Yesterday we had partly cloudy skies, warm temperatures in the upper 20s on the ridges to low 40s near 1000 with moderate ridge top winds. Overnight skies have mostly cleared and temperatures have dropped into the lower 20s. Today we should see partly cloudy skies again with a chance for scattered flurries and a rain drop or two at lower elevations. No accumulations are expected. Temperatures will be in the 20s around 3500 and close to 40F at 1000. Expect winds to remain light from the northeast with gusts into the teens on the ridge tops.

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 AKDT SAT APR 9 2011
.TODAY...MOSTLY CLOUDY. SCATTERED SNOW SHOWERS IN THE MORNING...
THEN SCATTERED SNOW AND RAIN SHOWERS IN THE AFTERNOON.
HIGHS IN THE UPPER 30S TO UPPER 40S. LIGHT WINDS.
.TONIGHT...MOSTLY CLOUDY. SCATTERED SNOW AND RAIN SHOWERS
IN THE EVENING...THEN SCATTERED SNOW SHOWERS AFTER MIDNIGHT. LOWS
IN THE LOWER 20S TO LOWER 30S. LIGHT WINDS.
.SUNDAY...PARTLY CLOUDY WITH ISOLATED SNOW SHOWERS IN THE
MORNING...THEN MOSTLY CLOUDY WITH SCATTERED SNOW AND RAIN SHOWERS IN
THE AFTERNOON. HIGHS IN THE UPPER 30S TO MID 40S. LIGHT WINDS.
.SUNDAY NIGHT...CLOUDY. SCATTERED SNOW AND RAIN SHOWERS
IN THE EVENING...THEN SCATTERED SNOW SHOWERS AFTER MIDNIGHT. LOWS
IN THE LOWER 20S TO LOWER 30S. LIGHT WINDS.
.MONDAY...SCATTERED SNOW SHOWERS IN THE MORNING...THEN NUMEROUS
RAIN AND SNOW SHOWERS IN THE AFTERNOON. HIGHS IN THE MID 30S TO LOWER
40S. LIGHT WINDS.
.MONDAY NIGHT...NUMEROUS SNOW SHOWERS. LOWS IN THE 20S.
.TUESDAY...MOSTLY CLOUDY WITH A CHANCE OF RAIN AND SNOW SHOWERS.
HIGHS 35 TO 45.

TEMPERATURE / PRECIPITATION

SEWARD 40 31 41 / 40 30 40
GIRDWOOD 46 26 43 / 30 30 50



WEATHER STATION SUMMARY for Turnagain Pass:
-3800 Sunburst Wx Station-
Currently 20 degrees. Wind light variable.
-2600 Seattle Ridge Wx Station-
Currently 21 degrees. Wind light variable.
-1800 Center Ridge Wx Station-
Currently 23 degrees. No new snow.


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: Apr 11, 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: OpenWide swaths of open river in the Placer Valley. Travel with extreme caution!
Skookum Drainage: ClosedSKOOKUM DRAINAGE CLOSED TO MOTORIZED USE ON APRIL 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: Open
Twentymile: ClosedClosed for the remainder of the 2017 season.
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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