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Turnagain Area Avalanche Advisory
Friday, April 2nd 2010 6:42 am by CNFAIC Staff
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
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BROUGHT TO YOU BY
The Bottom Line
Good morning backcountry travelers this is Carl Skustad with the Chugach National Forest Avalanche Information Center on Friday April 2nd, 2010 at 7 am. 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
Skookum Valley and Skookum Glacier are closed to motorized vehicles (snowmachines, helicopters, ATVs) except for subsistence uses.. This closure is directed in the current Chugach National Forest Land and Resource Management Plan. Placer River Drainage remains open for motorized use to Spencer Glacier.

WEATHER ROUNDUP
Winds stayed moderate to strong yesterday afternoon before dying off in the late evening. Current winds are light to moderate except for Sunburst ridge were we still see gusts in the teens and 20's. Snow totals from yesterday morning are: Eddies-13', Motorized parking lot in Turnagain Pass - 16', Sunburst - 9', and Johnson N Trail Head - 4'. This puts our 7 day total snowfall over 30 inches in Turnagain Pass. The radar this morning has precipitation heading east to west onshore near Seward. Not much for the Northern Kenai. Satellite images indicated cloud cover but models show little to no precip accumulation today. Look for the freeze line to go back up to approximately 1400 feet today.


AVALANCHE DISCUSSION
Todays avalanche danger is MODERATE with pockets of CONSIDERABLE due a complex snowpack consisting of buried weak layers of surface hoar and suncrusts. Newly formed windslabs and buried surface hoar will be the primary avalanche hazards today.

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully. Natural avalanche unlikely today unless we see the sun or increased wind or precip. Human triggered avalanches possible and likely in pocketed areas. If an avalanche is triggered it could go very large. 3 ft of new snow in the last week on top of buried surface hoar will promote large propagation and dangerous sized avalanches.

Areas where one could likely trigger an avalanche today exist on steep rollovers or hanging snow fields near ridgetops. Wind slabs will be present in the alpine. All aspects have either buried surface hoar (north aspects) or buried sun crusts (south aspects). These weak layers have cross over and duplication on east and west aspects.

We have limited observations from yesterday. If you get out today, routefinding and snow stability evaluation will be key. Take the time to examine the snow in front of you. It will change every few feet. Send us your observations using the submit button on the top of this page.

The sun is a critical watch out situation this time of year. Avalanche danger increases quickly during periods of rapid warming temperatures and direct sunlight.

CNFAIC Staff than sunny slopes, the buried surface hoar is a serious concern today. A party reported a large collapse on the ridge near the top of Sunburst 3 days ago. In the past week, there have been several human-triggered avalanches that have occurred on one of the MULTIPLE layers of buried surface hoar that are currently buried 2-4 feet deep in our snowpack.

Terrain management is the key today. Keep your slope angles below 35 degrees. AVOID traveling on any sunny slopes IF the sun comes out and get out of avalanche terrain immediately if it does. Remember that most of the avalanches that failed on the surface hoar have occurred on northern aspects.

Glide cracks are secondary concern today. These crevasse like features are those cracks that go all the way to the ground. Avoid traveling underneath these cracks. A full depth climax avalanche occurred on lower Goat Ridge in Girdwood Valley on 3/30/2010.


WEATHER FORECAST (National Weather Service)
WESTERN PRINCE WILLIAM SOUND-
INCLUDING...WHITTIER...SEWARD...GIRDWOOD...MOOSE PASS
500 AM AKDT FRI APR 2 2010

.TODAY...MOSTLY CLOUDY. NUMEROUS SNOW SHOWERS IN THE MORNING...THEN
SCATTERED RAIN AND SNOW SHOWERS IN THE AFTERNOON. SNOW ACCUMULATION
UP TO 1 INCH. HIGHS IN THE LOWER TO MID 40S. VARIABLE WIND TO 10 MPH.
NEAR SEWARD...NORTH WIND 15 MPH.
.TONIGHT...MOSTLY CLOUDY WITH A CHANCE OF SNOW. LOWS IN THE MID
20S TO LOWER 30S. VARIABLE WIND TO 10 MPH. NEAR SEWARD...NORTH WIND
10 TO 20 MPH.
.SATURDAY...MOSTLY CLOUDY. A CHANCE OF SNOW IN THE MORNING...THEN
SCATTERED SNOW AND RAIN SHOWERS IN THE AFTERNOON. HIGHS
IN THE UPPER 30S TO MID 40S. LIGHT WINDS EXCEPT NORTH 10 MPH NEAR
SEWARD.
.SATURDAY NIGHT...SNOW LIKELY. LOWS IN THE UPPER 20S TO MID 30S.
VARIABLE WIND 10 MPH.
.SUNDAY...SNOW AND RAIN LIKELY. HIGHS AROUND 40. EAST WIND 10 TO 15
MPH.
.SUNDAY NIGHT...MOSTLY CLOUDY WITH SCATTERED SNOW SHOWERS. LOWS
IN THE 20S.

TEMPERATURE / PRECIPITATION

SEWARD 44 29 43 / 60 40 50
GIRDWOOD 45 27 43 / 30 20 30


WEATHER STATION SUMMARY for last 24 hours at TURNAGAIN PASS
3800-Sunburst Wx Station
Temp (5am): 25 (2 degrees warmer than yesterday morning)
Winds: In last 24 hours winds have been moderate out of the east from 10 mph to the high 30's.


2600-Seattle Ridge Wx Station
Temp (5am): 26
Winds: Yesterday saw wind gusts in the 20's. Currently south winds are light.


1800-Center Ridge Wx Station
Temp (5am): 26 (1 degrees colder than yesterday morning)
Precip: 0 new snow, total snowpack is 146 after 7 inches of settlement.

Thanks for checking todays avalanche advisory. I will update this advisory tomorrow Saturday April 3rd, 2010 by 0700.

 Show the Complete North American Avalanche Danger Scale
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.

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 20, 2019 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Open
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: Open
Twentymile: ClosedClosed as of 3.20.19 due to lack of snow.
Seward District
Carter Lake: Open
Lost Lake Trail: OpenPlease stay on trail to avoid resource damage through forested areas.
Primrose Trail: OpenPlease stay on trail to avoid resource damage through forested areas.
Resurrection Pass Trail: ClosedClosed for the 2018/19 season. Next season will be open to motorized use.
Snug Harbor: Open
South Fork Snow River Corridor: ClosedClosed as of 3.20.19 due to lack of snow.
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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