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Turnagain Area Avalanche Advisory
Thursday, December 24th 2009 6:51 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 Thursday, December 24 at 7 am. This will serve as a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (advisory does not apply to highways, railroads, or operating ski areas).

ANNOUNCEMENTS
The beacon park is open at the Alyeska Resort. It's located opposite the Hotel Alyeska at the tram loop. It's a great place to practice your beacon rescue skills.

WEATHER ROUNDUP
In the last 24 hours, 6-8 inches of snow fell in Girdwood, 10 inches in Turnagain Pass, and 4 inches in Summit Lake. Approximate 3 day storm totals for Girdwood are 12-15 inches, Turnagain Pass 19 inches, and Summit Lake 9. These amounts are above the snowline. The snowline has fluctuated from sea level to 1200 ft. Almost all precip has been rain from sea level to 800 feet.

-The Center Ridge Wx Station at 1800 feet/Turnagain Pass-
recorded 10 inches of new snow and 1.1 inches of water in the last 24 hours. The current temp is 30.6F (2 degrees warmer than yesterday) with a total snowpack depth of 68 inches. 3 inches of settlement.

-The Sunburst Wx Station at 3800 feet/Turnagain Pass-
is showing 18 mph winds out of the ESE, with gusts of 30 mph. Very high sustained averages and gusts to 74 in the last 24 hours. The current temperature is 24 deg F

-The Summit Lake Wx Station at 1200 feet-
recorded 4inches of new snow and 0.3 inches of water in the last 24 hours. The current temp is 32F ( 3 degrees warmer than yesterday) with a total snowpack depth of 33 inches.

-The Fresno Ridge Wx Station at 3400 feet/Summit Lake-
recorded is showing 22 mph winds with gust of 29 mph out of the SE. Very high averages and gusts to 56 in the last 24

A very strong 962 mb low is located in the gulf spinning shortwave precipitation at us. The jet stream is cruising around the northern hemisphere like a good little jet stream then bam, it hits this low and turns directly north into mainland AK. Heavy cloud cover and mixed precip on the radar and satellite.

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


.500 AM AKST THU DEC 24 2009

.TODAY...RAIN ALONG THE COAST AND RAIN AND SNOW OVER HIGHER
ELEVATIONS. SNOW ACCUMULATIONS UP TO 2 INCHES OVER HIGHER ELEVATIONS.
HIGHS IN THE MID 30S TO LOWER 40S. NORTH TO EAST WIND 10 TO 20 MPH
EXCEPT SOUTHEAST WIND 15 TO 30 THROUGH PORTAGE VALLEY AND TURNAGAIN
ARM.
.TONIGHT...RAIN AND SNOW. SNOW ACCUMULATION 2 TO 4 INCHES OVER HIGHER
ELEVATIONS. LOWS IN THE MID 20S TO UPPER 30S. NORTH TO EAST WIND 10
TO 20 MPH EXCEPT SOUTHEAST WIND 15 TO 30 THROUGH PORTAGE VALLEY AND
TURNAGAIN ARM.
.CHRISTMAS DAY...RAIN AND SNOW LIKELY. SNOW ACCUMULATION UP TO
1 INCH. HIGHS IN THE LOWER 30S TO LOWER 40S. NORTH TO EAST WIND 10 TO
20 MPH EXCEPT SOUTHEAST WIND 15 TO 30 THROUGH PORTAGE VALLEY AND
TURNAGAIN ARM.
.FRIDAY NIGHT...NUMEROUS SNOW SHOWERS. LOWS IN THE LOWER 20S TO
MID 30S. NORTH TO EAST WIND TO 15 MPH.
.SATURDAY...SNOW AND RAIN LIKELY. HIGHS IN THE UPPER 20S TO UPPER
30S. EAST WIND 10 TO 20 MPH.

TEMPERATURE / PRECIPITATION

SEWARD 40 34 38 / 80 80 60
GIRDWOOD 41 37 41 / 80 60 60


AVALANCHE DISCUSSION
It's hard to say if the current cycle of precip and avalanche activity has peaked yet. I believe it did late yesterday. However, with too much uncertainty the avalanche hazard will elevate one click today. Today's avalanche hazard is HIGH on steep terrain. Natural avalanches are likely today and human avalanches are very likely on slopes steeper than 35 degrees. All CNFAIC Staff areas have CONSIDERABLE avalanche hazard. Considerable means natural avalanches possible and human triggered avalanches likely.

We actually saw the above-mentioned hazards come to fruition yesterday afternoon. Jon and I climbing out of the rain and into heavy snow and wind on Tincan mountain. Talking with CNFAIC Staff skiers and building observations of our own is the basis for today's increased hazard. Natural and human triggered avalanches were common on most role overs steeper than 35 degrees. Large spread collapsing was reported. CNFAIC Staff professional reports from the Girdwood Valley indicated similar conditions. The avalanches mentioned failed on the 24 hour old snow interface, 6-8 inches deep, (CTE 4 14cm x2, CTM 14 35cm x2). I'm not convinced that this thinner slab won't step down to the buried surface hoar in some instances. If this were the case large avalanches would occur. We had limited visibility and could not see upper elevations; however, winds have been ripping and starting zones are loaded.


I will issue the Christmas 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


 Show the Complete North American Avalanche Danger Scale
3 Considerable Alpine / Above 2,500' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
3 Considerable Treeline / 1,000'-2,500' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.
3 Considerable Below Treeline / Below 1,000' Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.

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

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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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