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Turnagain Area Avalanche Advisory
Tuesday, December 15th 2009 7:01 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 Matt Murphy with the Chugach National Forest Avalanche Information Center on Tuesday December 15th 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
All areas designated for snowmachines (except Placer and 20 Mile) on the Chugach National Forest are open. Please remember that Center and Divide Creek near the Johnson Pass Trailhead are always closed due to the current Forest Plan. These areas are periodically patrolled by law enforcement. We are monitoring the snow at Placer and 20 Mile and will open those areas as soon as there is enough snow, these colder temps down low are really helping these areas.


WEATHER ROUNDUP
Will recent weather effect avalanche conditions today?
Well, lets take a closer look at the precip, winds, and temps.

Hindcast (Last 24 hours)

3800 -Sunburst Wx Station-
Temperatures were 19-20 degrees with calm winds averaging 3-8 mph from the E with a max calm gust of 12 mph

2600-Seattle Ridge Wx Station-
Winds have been calm averaging 4-14 mph out of the ESE with a max light gust of 21 mph

1800-Center Ridge Wx Station-
Precip: 0.1 inch of water and 1 inch of new snow
Total depth of 55 inches
Temperature Range: 19-27


Nowcast

Light snow is falling in Girdwood as of 5am with about 4 inches of new accumulation in the parking lot. The Middleton radar shows scattered to moderate precip mostly over Cordova and the Kenai radar shows light precip moving north. Temps and precip were pretty consistent at most of the weather stations that I checked this morning. One difference is Summit Lake is showing 3 inches of new snow compared to 1 inch at Turnagain Pass. Temps currently range from 23 degrees at sea level to 20 degrees at 3800' and all ridgetop winds are still calm.

Forecast

WESTERN PRINCE WILLIAM SOUND-
INCLUDING...WHITTIER...SEWARD...GIRDWOOD...MOOSE PASS
500 AM AKST TUE DEC 15 2009

.TODAY...PERIODS OF SNOW. SNOW ACCUMULATION 1 TO 3 INCHES.
HIGHS IN THE LOWER 20S TO LOWER 30S...WARMEST ALONG THE COAST.
LIGHT WINDS EXCEPT NORTH TO 15 MPH NEAR SEWARD.
.TONIGHT...SNOW. SNOW ACCUMULATION 4 TO 8 INCHES. LOWS IN THE
TEENS TO LOWER 20S INLAND AND MID TO UPPER 20S ALONG THE COAST.
LIGHT WINDS EXCEPT NORTH TO 15 MPH NEAR SEWARD.
.WEDNESDAY...SNOW LIKELY. SNOW ACCUMULATION UP TO 2 INCHES
EXCEPT 4 TO 8 INCHES IN THE PORTAGE VALLEY TO GIRDWOOD AREA.
HIGHS 15 TO 25. LIGHT WINDS EXCEPT NORTH TO 15 MPH NEAR SEWARD.

TEMPERATURE / PRECIPITATION

SEWARD 28 23 23 / 80 70 60
GIRDWOOD 25 21 21 / 100 90 80

Short Term Weather Models (NAM) for the Kenai Mountains near Turnagain Pass
Sea-level: 0.1 inches of water forecasted today
3000: temps forecasted below freezing today around 20 degrees with winds 5-10mph
6000: temps forecasted below freezing today around 15 degrees with winds 10-20mph


AVALANCHE DISCUSSION
Recent weather will not contribute to the avalanche danger today, and the NWS is not forecasting much precip or wind for the Turnagain Pass area.

Due to insignificant results in recent snow stability test pits, zero significant natural or human-triggered avalanches reported or observed recently, and a mild weather forecast from the NWS, todays avalanche danger level will remain at LOW. LOW is defined as: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Natural and human-triggered avalanches unlikely. Very small avalanches in widespread areas; or small avalanches in isolated areas.

Normal Caution is advised.

The next avalanche concern that we are watching out for is on the current surface snow. There are widespread firm or slippery surfaces created by the wind, sun, and warm temps from last week. Surface hoar formed from sea level to as high as 2800', however, the most defined surface hoar and faceted surface snow is below 1600'; so, due to the slippery surfaces and formation of surface hoar and faceted sugary surface snow, the worst weak layer in the near future will be below 2800'. These mid to lower elevations could become our next big problem when we get the next big weather event. Just as a reminder, most of the bowls along Seattle Ridge are below 2800'. CNFAIC Staff areas with steep terrain below 2800' include but are not limited to the lower part of Eddies, Pete's North, and the terrain behind the "Welcome to the Kenai" sign near Pyramid along Seattle Ridge.

Always remember that safe backcountry travel requires training and experience. You control your own risk by choosing where, when, and how you travel.

Thanks for checking todays avalanche advisory. The next one will be posted tomorrow Wednesday December 16.
 Show the Complete North American Avalanche Danger Scale
0 NO RATING Alpine / Above 2,500'
0 NO RATING Treeline / 1,000'-2,500'
0 NO RATING Below Treeline / Below 1,000'

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 22, 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: ClosedClosed as of 3/22. Unfortunately HEAVY rain over the past week has washed much of the snow off the lower stretches of this trail.
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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