Tuesday, April 12th 2011 6:51 am by Jon Gellings
ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.
The avalanche danger today is LOW with pockets of MODERATE. Many avalanche prone slopes in our core advisory area of Turnagain Pass are unlikely to avalanche today, but certain places contain a higher possibility of triggering a slab avalanche. These pockets of MODERATE include steep North facing slopes at upper elevations that are showing reactive buried layers of surface hoar, as well as on steep, sun-affected slopes during the afternoon.
We are not at a full-on LOW danger rating, so steeper slopes over 35 degrees should be approached with caution if you are uncertain of their stability. Many people have been out over the past few days skiing and riding steep North facing slopes and couloirs, with no incidents or reported avalanches since last Friday. However, with a few buried layers of surface hoar recently showing clean and fast shears (Q1), prudent personal decision making is necessary to abate this hazard.
Our main concern is still for persistent slab avalanches. While they are becoming less likely, as Wendy stated yesterday, they are still possible and could end up biting you if unaware of their presence and current reactivity. Here is a video from yesterday, showing exciting compression test results, even though several people had previously skied this slope and similar ones throughout Turnagain Pass without triggering anything.
A pit profile for this location is available here.
Outlying areas outside of Turnagain Pass containing deeper recent snowfalls and/or higher elevations likely still show signs of an increased hazard, and should be travelled through accordingly.
The secondary concern for today is for wet snow avalanches on steep slopes directly facing the sun during the warmest part of the day (1:00pm-6:00pm). Lower elevation slopes facing this direction are likely to become saturated up to several feet deep, but are unlikely to avalanche unless they are on steep, unsupported slopes. Sinking into snow beyond your ankles should clue you into this increasing instability.
Encyclopedia of avalanche terms.
Winds are not likely to increase significantly, therefore will not affect the snowpack adversely. Temperatures should be reaching into the upper 30s, potentially affecting the stability on lower elevation slopes, as well as on Southerly aspects during the afternoon. There is a bit of precipitation moving around in Prince William Sound, but radar, satellite, forecasts, and models all point to no significant impact in Turnagain Pass.
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 AKDT TUE APR 12 2011
.TODAY...MOSTLY CLOUDY WITH SCATTERED SNOW SHOWERS IN THE MORNING...
BECOMING PARTLY CLOUDY IN THE AFTERNOON. HIGHS IN THE 40S. LIGHT
WINDS EXCEPT NORTH 10 TO 15 MPH NEAR SEWARD.
.TONIGHT...PARTLY CLOUDY. ISOLATED RAIN AND SNOW SHOWERS IN THE
EVENING. LOWS IN THE LOWER 20S TO LOWER 30S. VARIABLE WIND TO 10 MPH.
NEAR WHITTIER...WEST WIND 15 TO 30 MPH.
.WEDNESDAY...PARTLY CLOUDY. ISOLATED RAIN AND SNOW SHOWERS IN THE
AFTERNOON. HIGHS IN THE 40S. VARIABLE WIND 10 MPH INLAND. NEAR SEWARD
AND WHITTIER...NORTH TO WEST WIND 15 TO 30 MPH.
TEMPERATURE / PRECIPITATION
SEWARD 45 27 45 / 30 20 20
GIRDWOOD 43 22 43 / 0 20 0
WEATHER STATION SUMMARY for Turnagain Pass:
-3800 Sunburst Wx Station-
20 degrees. ENE wind 9mph gusting to 15mph.
-2600 Seattle Ridge Wx Station-
24 degrees. SE wind 11mph gusting to 15mph.
-1800 Center Ridge Wx Station-
26 degrees. No new snow.
|Show the Complete North American Avalanche Danger Scale|
|Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.|
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: May 06, 2018 )
|AREA||STATUS||WEATHER AND RIDING CONDITIONS|
|Johnson Pass:||Closed||Closed as of April 20th|
|Placer River:||Closed||Closed as of April 17th|
|Skookum Drainage:||Closed||Closed as of April 1st.|
|Turnagain Pass:||Closed||Closed as of May 7th. Happy summer, see ya when the snow flies!|
|Twentymile:||Closed||Closed as of April 13th|
|Carter Lake:||Closed||Closed as of 4/27|
|Lost Lake Trail:||Closed||Closed as of April 13th|
|Primrose Trail:||Closed||Closed as of April 13th|
|Resurrection Pass Trail:||Closed||Closed as of April 20th|
|Snug Harbor:||Closed||Closed as of 4/27|
|South Fork Snow River Corridor:||Closed||Closed as of April 13th|
|Summit Lake:||Closed||Closed as of April 20th|
SNOW AND AVALANCHE HOTLINE (907) 754-2369
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