Good morning backcountry travelers this is Kevin Wright with the Chugach National Forest Avalanche Information Center on Saturday, March 5th 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).
Today’s avalanche danger rating is Low with pockets of MODERATE. Pockets of hard wind slab over loose facets are the primary concern. The hazard is generally confined to steep, shallow snow in complex terrain.
A slight chance of snow south of Moose Pass will probably not have much effect on the avalanche conditions. Snow quality right now is best suited for long flat tours, watching the Iditarod, or doing taxes.
Despite the horrendous riding quality on the surface, the avalanche stability is generally ok. Most areas in Turnagain Pass are unlikely to trigger an avalanche. In more complex and steeper terrain it is still possible to find the old weaknesses.
The specific avalanche hazard today is a combination of wind slab and the deeper weaknesses formed back in December. The entire region seems to be covered by a stiff layer of winded snow with variable thickness. Sometimes that wind slab is supportable and thick, sometimes you punch through in the thin areas. Everywhere underneath that firm layer is a soft layer of weaker snow. Strong snow over weak snow is exactly the recipe needed to create an avalanche.
This avalanche happened a week ago in Seattle creek. Notice the snowmachine highmark track that goes up the left side of the photo. See the photo gallery for CNFAIC Staff recent photos.
Take a look at a recent pit profile here. This was dug on an old crown in Seattle creek and shows the poor structure that is causing the recent avalanche events.
Areas to avoid are steep, wind loaded, shallow, rocky, and unsupported terrain. The areas south of Turnagain Pass in the interior Kenai continue to have less stable conditions. Read the Summit advisory today for a summary of that zone.
The past several days have been calm and clear. It hasn’t snowed in nearly 2 weeks and the last major wind storm was a week ago. Currently temperatures are inverted with Portage at 0 and Sunburst at 16 degrees. A slight chance of snow today is concentrated towards Seward. Increasing clouds today. Temperatures in the 20s. Light to moderate wind from the West.
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-
500 AM AKST SAT MAR 5 2011
.TODAY…INCREASING CLOUDS. A SLIGHT CHANCE OF SNOW IN THE AFTERNOON
SOUTH OF MOOSE PASS. HIGHS IN THE MID 20S TO LOWER 30S. VARIABLE WIND
10 MPH. NEAR SEWARD…NORTH 25 TO 40 MPH. NEAR WHITTIER…WEST WIND
25 TO 40 MPH BECOMING VARIABLE 10 MPH IN THE AFTERNOON.
.TONIGHT…MOSTLY CLOUDY. A CHANCE OF SNOW…MAINLY SOUTH OF MOOSE
PASS. LOWS 10 TO 25 ABOVE…COOLEST INLAND. VARIABLE WIND 10 MPH
EXCEPT NORTH 10 TO 25 MPH NEAR SEWARD.
.SUNDAY…MOSTLY CLOUDY. A SLIGHT CHANCE OF SNOW IN THE
MORNING…MAINLY SOUTH OF MOOSE PASS. HIGHS IN THE LOWER TO MID 30S.
VARIABLE WIND 10 MPH EXCEPT NORTH 10 TO 15 MPH NEAR SEWARD.
.SUNDAY NIGHT…PARTLY CLOUDY. LOWS 15 TO 25…COOLEST INLAND.
VARIABLE WIND 10 MPH.
.MONDAY…PARTLY CLOUDY WITH SCATTERED SNOW SHOWERS. HIGHS IN THE
30S. EAST WIND 10 TO 15 MPH.
.MONDAY NIGHT…PARTLY CLOUDY WITH ISOLATED SNOW SHOWERS. LOWS
15 TO 25.
TEMPERATURE / PRECIPITATION
SEWARD 31 26 35 / 20 40 20
GIRDWOOD 25 20 34 / 0 0 0
WEATHER STATION SUMMARY for Turnagain Pass:
-3800′ Sunburst Wx Station-
Temperature 16 degrees. Light wind from the ENE.
-2600′ Seattle Ridge Wx Station-
Temperature 14. Light wind from the NNE.
-1800′ Center Ridge Wx Station-
Temperature 7 degrees. No new snow.