Good morning backcountry travelers this is Lisa Portune with the Chugach National Forest Avalanche Information Center on Monday, 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 (this advisory does not apply to highways, railroads, or operating ski areas).
We’re starting an incentive program to encourage everyone to submit snow and avalanche observations. Each quality observation will earn you one chance to win a monthly prize. At the end of this season all the submissions will go into a drawing for an avalanche beacon of your choice. Thanks for all the great work, and keep sending in those observations!
The avalanche danger rating remains at MODERATE today. While the likelihood of triggering an avalanche continues to decline, areas of instability still exist. Human triggered avalanches are still possible if you look hard enough. Predicting where you could trigger an avalanche is especially tricky right now, so use good travel techniques to minimize your exposure. Our persistent weak layers consist of numerous layers of buried surface hoar that formed in December and facets above and below the Thanksgiving Rain Crust. Unpredictable hard windslab over weak faceted snow also exists near ridgetops and in crossloaded terrain.
While most snowpit stability tests are showing little to no reactivity, and the frequency of human-triggered avalanches has declined this past week, the poor structure of our snowpack still demands caution…especially in shallow steep high-consequence terrain. This is a difficult-to-manage hazard in the form of persistent weak layers and hard windslab. Ski cuts are generally not effective with these types of instabilities. The most recent reported human triggered avalanche happened on Thursday when a snowboarder triggered an avalanche on the south face of Cornbiscuit on a steep rollover. He was caught and carried but luckily not buried. This avalanche broke about a foot deep and 50 feet wide and ran 800-1000 feet down slope.
Snow conditions right now are variable. Last week’s sporadic winds hit the higher elevations and passes where you’ll find dense windslab, exposed ice crusts, dust on crust, and wind-buffed powder. More protected areas down low hold softer snow and monster sized surface hoar (see photo below).
Photo by Bob Sutherland
Encyclopedia of terms: www.fsavalanche.org/Encyclopedia.aspx
It has been 12 days since our last snowfall. In the last 24 hours, ridgetop winds averaged 5-10mph out of the north and west while temps have gradually warmed up to the low single digits at the higher elevations. Temperatures this morning range from -11F at sea level to 2F at the higher elevations. Skies are currently clear but are expected to cloud up today as a weak upper low moves into southcentral. Turnagain Pass may see a trace to one inch of snow before skies clear again this evening. Ridgetop winds should remain in the 5-10mph range today with mountain temps in the single digits.
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 MON JAN 17 2011
.TODAY…SNOW SHOWERS LIKELY ALONG THE COAST BY AFTERNOON WITH
UP TO 2 INCHES ACCUMULATION. ELSEWHERE…MOSTLY CLOUDY WITH A
CHANCE OF SNOW SHOWERS. HIGHS 10 BELOW TO 5 ABOVE EXCEPT IN THE
TEENS ALONG THE COAST. VARIABLE WIND 10 MPH.
.TONIGHT…SNOW SHOWERS LIKELY ALONG THE COAST EARLY EVENING
WITH UP TO 1 INCH ACCUMULATION. ELSEWHERE…MOSTLY CLOUDY WITH
A SLIGHT CHANCE OF SNOW SHOWERS IN THE EVENING…THEN CLEARING.
LOWS ZERO TO 15 BELOW EXCEPT 10 TO 15 ABOVE ALONG THE COAST.
VARIABLE WIND TO 10 MPH. NEAR SEWARD…NORTH WIND INCREASING TO
15 TO 25 MPH. NEAR WHITTIER…WEST WIND INCREASING TO 15 TO 25 MPH
WITH GUSTS TO 35 MPH.
.TUESDAY…SUNNY. HIGHS 5 TO 15 ABOVE EXCEPT 15 TO 25 ALONG THE
COAST. VARIABLE WIND TO 10 MPH. NEAR SEWARD…NORTH WIND
15 TO 25 MPH IN THE MORNING. NEAR WHITTIER…WEST WIND 20 TO 30 MPH
WITH GUSTS TO 40 MPH DECREASING TO 10 TO 20 MPH IN THE AFTERNOON.
.TUESDAY NIGHT…INCREASING CLOUDS WITH SNOW LIKELY AFTER MIDNIGHT.
LOWS 10 BELOW TO 5 ABOVE EXCEPT IN THE TEENS ALONG THE COAST.
NORTH TO EAST WIND TO 15 MPH.
TEMPERATURE / PRECIPITATION
SEWARD 16 10 24 / 50 30 0
GIRDWOOD 7 0 12 / 20 20 0
WEATHER STATION SUMMARY for Turnagain Pass:
-3800′ Sunburst Wx Station-
recorded winds averaging 4-12mph out of the west the last 24 hours. Temps bottomed out at -10F yesterday and have warmed up to 1F this morning.
-2600′ Seattle Ridge Wx Station-
recorded winds averaging 2-11mph out of the north the last 24 hours. Temps bottomed out at -12F yesterday and have warmed up to 2F this morning.
-1800′ Center Ridge Wx Station-
recorded no new snow the last 12 days. Temps hit -12F yesterday and have warmed up to 2F this morning.