CNFAIC LogoCNFAIC Logo
Turnagain Area Avalanche Advisory
Sunday, January 17th 2010 6:55 am by CNFAIC Staff
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
Previous ForecastNext Forecast
BROUGHT TO YOU BY
The Bottom Line
Good morning backcountry travelers this is Lisa Portune with the Chugach National Forest Avalanche Information Center on Sunday, January 17th at 7am. 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
There are still spots available for next weekend's snowmachine avalanche workshop in Turnagain Pass. Sign up at the Alaska Avalanche School (alaskaavalanche.com) or call (907)345-0878. They will cover rescue procedures and snow assessments with some class room and lots of field work.

WEATHER ROUNDUP
AnCNFAIC Staff 6-8 inches of new snow fell in the last 24 hours in Turnagain Pass. This is in addition to the 7 inches that fell Friday night, bringing our snowfall total for the week to around 20-24 inches. Yesterday ridgetop winds were all over the board, averaging 5-20mph out of the east on Sunburst and 0-5mph out of the southeast on Seattle Ridge. Mountain temperatures were in the mid to high 20s. The winds picked up last night in Turnagain Pass and are currently averaging 20-30mph out of the east and southeast with gusts in the 30s and 40s. Temperatures warmed up by a few degrees last night turning snow to rain at sea level. Skies are mostly cloudy right now while temps currently range from 22F at 3800 feet to 36F in Portage. A complex low pressure system in the gulf is responsible for this long-awaited new snow. Expect continued snow showers today at the higher elevations with an additional 1-4 inches forecasted. Mountain temps will remain in the mid to high 20s while winds will average 10-25mph out of the southeast and east.

-The Center Ridge Wx Station at 1800 feet/Turnagain Pass-
recorded 6 inches of new snow and 0.6 inches water in the last 24 hours. The current temp is 28F (1 degrees warmer than yesterday) with a total snowpack depth of 71 inches.

-The Sunburst Wx Station at 3800 feet/Turnagain Pass-
recorded light to moderate easterly winds yesterday averaging 5-20mph. The current temp is 22F (2 degrees warmer than yesterday) with winds averaging 25-30mph out of the east.

-The Summit Lake Wx Station at 1200 feet-
recorded 2 inches of new snow and 0.1 inches water in the last 24 hours. The current temp is 23F (4 degrees colder than yesterday) with a total snowpack depth of 29 inches.

-The Fresno Ridge Wx Station at 3400 feet/Summit Lake-
recorded moderate southerly winds yesterday averaging 15-25mph with gusts in the 20s and 30s. The current temp is 23F (1 degrees warmer than yesterday) with winds averaging 10-15mph out of the southeast.

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

500 AM AKST SUN JAN 17 2010

.TODAY...PERIODS OF SNOW. POSSIBLY MIXED WITH RAIN AT TIMES. SNOW
ACCUMULATION 1 TO 4 INCHES. HIGHS IN THE 30S. EAST WIND 10 TO 20 MPH
EXCEPT NORTH WIND 10 TO 25 MPH NEAR SEWARD.
.TONIGHT...SNOW LIKELY. ADDITIONAL SNOW ACCUMULATION UP TO 3 INCHES.
LOWS IN THE 20S. VARIABLE WINDS 10 MPH. NEAR SEWARD...
NORTHEAST WIND 15 MPH SHIFTING TO THE SOUTHEAST AFTER
MIDNIGHT.
.MARTIN LUTHER KING JR DAY...SNOW AND RAIN LIKELY. ADDITIONAL SNOW
ACCUMULATION UP TO 3 INCHES. HIGHS IN THE 30S. VARIABLE WINDS 10 MPH
EXCEPT NORTHEAST 10 TO 20 MPH SOUTH OF MOOSE PASS.

TEMPERATURE / PRECIPITATION

SEWARD 36 29 37 / 80 70 70
GIRDWOOD 36 26 34 / 80 60 60


AVALANCHE DISCUSSION
It should come as no surprise that the avalanche hazard has increased since yesterday. Today, the avalanche danger is rated CONSIDERABLE on all slopes steeper than 35 degrees. We now have 20-24 inches of new snow on top of a slick crust and strong winds transporting this snow to leeward aspects. Dangerous avalanche conditions exist, especially on windloaded slopes. Human-triggered avalanches are likely today on slopes steeper than 35 degrees with natural avalanches possible on any actively loading slopes.

We received numerous reports of avalanche activity yesterday from Turnagain Pass to the Girdwood Valley. One of our observers reported big soft slabs releasing on steep rollovers on Tincan while anCNFAIC Staff observer reporting whumphing in the flatter areas below treeline. Ski cuts in the upper elevations of the Girdwood Valley produced 4-6 inch thick soft slabs running on the crust, propagating down the walls of a steep chute. On Thursday of this past week, one of our observers reported a skier triggered avalanche in a west facing, windloaded chute at 3800 feet on Pastoral. This slide ripped out wall to wall and ran 900 feet on a crust layer. The crown face ranged from 6 inches to 1.5 feet deep.

The buried rain crust extends to 3000 feet with buried wind crusts and old hardslab above 3000 feet. In CNFAIC Staff words, we have up to 2 feet of new snow sitting on slick bed surfaces at all elevations. The snow that fell this past week came in upside down, meaning it started off light and dry on Monday and is now warm and heavynot the ideal setup for snow accumulating on top of a slick crust. The light, dry snow did not bond very well with the crust, and now we have an increasingly thick and heavy slab forming on top.a sure recipe for avalanches. Layers of facets and surface hoar exist on top of and below the crust at the lower and mid elevations, which means well be dealing with instabilities on this layer for an unfortunate while.

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.

 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: Jan 13, 2019 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Open
Placer River: Open
Skookum Drainage: Open
Turnagain Pass: Open
Twentymile: ClosedClosed. Forest Service is monitoring conditions.
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: 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
© 2019 Chugach National Forest Avalanche Information Center. All rights reserved.
FCNFAIC