Tuesday, March 1st 2011 6:53 am by Jon Gellings
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
The avalanche danger is MODERATE for triggering a wind slab at ridgeline elevations. These avalanches are the most possible in steep rocky terrain and cross loaded gullies. Any new avalanche also has the possibility of breaking into old weak layers, creating a larger avalanche.
Wind slabs are still our primary concern today. These features could allow a backcountry traveler to get out onto a steep slope before fracturing above them. Now that these slabs have been sitting in place for a few days, they are likely to be more resistant to initial failure, but if it happens, there could be wider propagation. Many areas have been wind scoured down to crusts, old tracks, and facets, making for poor riding conditions. Searching for softer surface conditions could lead you right into wind loaded terrain. These wind slabs could possibly be triggered in steep rocky terrain, as well as on slopes and in gullies which have been cross loaded.
Our secondary concern is of avalanches breaking into old weak faceted snow, which could produce a much larger avalanche. We can not forget about this instability, even if it is several days or weeks until a new avalanche breaks down to these layers. Areas with an average snow cover of less than 5-6 feet deep are more prone to this type of instability, especially if the slope in question is steep and has been recently wind loaded. These unmanageable hard slabs are likely difficult to trigger, but can break if the right spot is found.
Winds are unlikely to be strong enough to transport any more snow today, although some areas near Turnagain Arm may see a few snow plumes near ridges. Temperatures look like they will be similar to yesterday, and there is no new precipitation forecasted for today.
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.
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. Thanks and have a great day.
The NWS weather forecast for:
WESTERN PRINCE WILLIAM SOUND-
500 AM AKST TUE MAR 1 2011
.TODAY...SUNNY. HIGHS IN THE LOWER 20S TO LOWER 30S. VARIABLE
WIND TO 10 MPH. NEAR SEWARD AND WHITTIER...NORTH AND WEST WIND
15 TO 25 MPH WITH GUSTS TO 35 MPH DECREASING TO 10 TO 20 MPH
IN THE AFTERNOON.
.TONIGHT...CLEAR. LOWS 10 BELOW TO 5 ABOVE EXCEPT IN THE TEENS
ALONG THE COAST. LIGHT WINDS. NEAR SEWARD...NORTH WIND 10 TO 20 MPH.
NEAR WHITTIER...WEST WIND TO 15 MPH WITH GUSTS TO 30 MPH.
.WEDNESDAY...SUNNY. HIGHS IN THE LOWER 20S TO LOWER 30S.
VARIABLE WIND TO 10 MPH. NEAR SEWARD...NORTH WIND 10 TO 20 MPH.
NEAR WHITTIER...WEST WIND 15 TO 25 MPH WITH GUSTS TO 35 MPH.
TEMPERATURE / PRECIPITATION
SEWARD 28 17 27 / 0 0 0
GIRDWOOD 20 5 20 / 0 0 0
WEATHER STATION SUMMARY for Turnagain Pass:
-3800 Sunburst Wx Station-
(@ 4am) Temperature 12 degrees. NW winds 5-10mph, gusting to 20.
-2600 Seattle Ridge Wx Station-
Temperature 15 degrees. Calm NW winds gusting to 10.
-1800 Center Ridge Wx Station-
Temperature 11 degrees. No new snow.
|Show the Complete North American Avalanche Danger Scale|
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).
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|
|Twentymile:||Closed||Closed. Forest Service is monitoring conditions.|
|Lost Lake Trail:||Open||Please stay on trail to avoid resource damage through forested areas.|
|Primrose Trail:||Open||Please stay on trail to avoid resource damage through forested areas.|
|Resurrection Pass Trail:||Closed||Closed for the 2018/19 season. Next season will be open to motorized use.|
|South Fork Snow River Corridor:||Open|
SNOW AND AVALANCHE HOTLINE (907) 754-2369
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