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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Kevin Wright  
Saturday, February 26th 2011
Created: Feb 26th 6:23 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.
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The Bottom Line
Good morning backcountry travelers this is Kevin Wright with the Chugach National Forest Avalanche Information Center on Saturday, February 26th 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).

BOTTOM LINE
Todays avalanche danger rating is MODERATE. Very specific wind loaded areas will have a CONSIDERABLE danger with heightened avalanche hazard on the lee sides of ridges. Deep slab concerns are focused in shallow snowpack zones and specific shallower points in steeper terrain.

AVALANCHE DISCUSSION
Yesterdays storm brought no significant snow to Turnagain Pass. Wind however was strong through the region and that trend continues today. Gusts have been measured as high as 89mph on Seattle ridge. Wind loading was very obvious yesterday and speeds accelerated overnight. Observations show that East, North, and South aspects are the dominant lee sides depending on location. Human triggered avalanches in the currently wind loading steep terrain are likely today.

Check out this photo from yesterday showing the scouring effects of recent wind on windward slopes.

541-DSC_8088.jpg


Its now been 2 1/2 weeks since the last confirmed deep slab avalanche in Turnagain Pass. More recent deep avalanches have happened in shallower and weaker areas including Raggedtop and Summit. The general trend has been for these weaknesses to slowly become more difficult to trigger. Right now they seem to be quite stubborn, but could reawaken with a big storm load in the future. Likely trigger points include areas where you could affect the weak layer in shallow spots. Traveling in shallow areas like Summit deserves a completely different level of caution than Turnagain Pass. See the Summit advisory today for a discussion of those concerns and recent observations.

WEATHER ROUNDUP
Strong wind yesterday continues through today. A high wind warning is in effect near Whittier. Turnagain arm is channeling a west wind with gusts recorded into the 80s overnight. Weather stations are showing West or Northwest wind through Turnagain and Southwest around Summit. Temperatures dropped fast yesterday going from 32 to 0 currently at the ridgetops. Today clear skies, strong wind, and cold temperatures are expected.

ANNOUNCEMENTS An APU student is conducting a survey on backcountry skiing group dynamics. Click on the link to participate in research on avalanche safety. Click here to take survey

The Forest Service is installing winter use bridges across Granite creek in Turnagain Pass. Be aware of an ice road from the Lyon creek bridge south towards Johnson Pass on the West side of the highway. Heavy equipment will also be used in the area.


Wendy 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 AKST SAT FEB 26 2011

...HIGH WIND WARNING IN EFFECT UNTIL 6 AM AKST SUNDAY NEAR
WHITTIER...
.TODAY...PARTLY CLOUDY. HIGHS 15 TO 25. NORTHWEST WIND 15 TO 30 MPH
EXCEPT WEST WIND 40 TO 55 MPH WITH GUSTS TO 75 MPH NEAR WHITTIER.
NEAR SEWARD...NORTH 30 TO 45 MPH.
.TONIGHT...CLEAR. LOWS 10 BELOW TO 15 ABOVE...COOLEST INLAND.
NORTHWEST WIND 10 TO 25 MPH EXCEPT WEST WIND 40 TO 55 MPH WITH GUSTS
TO 75 MPH NEAR WHITTIER. NEAR SEWARD...NORTH 35 TO 50 MPH.
.SUNDAY...SUNNY. HIGHS 15 TO 20. NORTHWEST WIND 10 TO 25 MPH EXCEPT
WEST WIND 30 TO 45 MPH WITH GUSTS TO 60 MPH NEAR WHITTIER. NEAR
SEWARD...NORTH WIND 30 TO 45 MPH.
.SUNDAY NIGHT...CLEAR. LOWS 5 BELOW TO 15 ABOVE...COOLEST INLAND.
NORTHWEST WIND 10 TO 25 MPH EXCEPT NORTH 25 TO 40 MPH NEAR
SEWARD. NEAR WHITTIER...WEST WIND 25 TO 40 MPH WITH GUSTS TO 55 MPH.
.MONDAY...SUNNY. HIGHS IN THE 20S. NORTHWEST WIND 10 TO 20 MPH
EXCEPT NORTH 20 TO 35 MPH NEAR SEWARD.

TEMPERATURE / PRECIPITATION

SEWARD 27 15 20 / 0 0 0
GIRDWOOD 21 6 18 / 0 0 0



WEATHER STATION SUMMARY for Turnagain Pass:
-3800 Sunburst Wx Station-
Temperature 0 degrees. Strong wind from the NW, gusting to 48.
-2600 Seattle Ridge Wx Station-
Temperature 5 degrees. Strongest recorded wind in the region with sustained wind in the 40s and max gust to 89 overnight from the West.
-1800 Center Ridge Wx Station-
Temperature 11 degrees. No new snow recorded.

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 28, 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: OpenPlacer remains open but SKOOKUM DRAINAGE will close to motorized use on April 1st.
Skookum Drainage: OpenSKOOKUM DRAINAGE CLOSES TO MOTORIZED USE ON APRIL 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: Open
Twentymile: Open
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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