Good morning backcountry travelers this is Lisa Portune with the Chugach National Forest Avalanche Information Center on Monday, January 25th 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).
Despite no new snow in the last five days in Turnagain Pass, the weather has been perfect…sunny skies, light winds, and mountain temps in the 20’s since last Wednesday. Yesterday ridgetop winds were light with temperatures ranging from the mid to high 20’s in the mountains. The winds on the northern end of Seattle Ridge, however, averaged 15-20mph out of the southeast for a few hours yesterday morning but calmed down by noon. Yesterday was the fifth day of an inversion with sea level temps in the single digits and teens. As of 4am this morning, ridgetop winds are light out of the north with clear skies above the fog that moved in last night. We still have a slight inversion this morning with temps currently ranging from 22F at 3800 feet to 15F at sea level. A high pressure ridge will continue to bring sunny skies and light winds today with a few high clouds moving in by afternoon. Mountain temps will be in the high teens to mid 20’s while ridgetop winds will be light out of the northeast.
-3800′ Sunburst Wx Station-
recorded light easterly winds yesterday averaging 1-10mph. The current temp is 22F (4 degrees colder than yesterday) with winds averaging 5mph out of the northwest.
-2600′ Seattle Ridge Wx Station-
recorded light to moderate southeasterly winds yesterday averaging 1-20mph. Winds are currently averaging 1mph out of the northeast.
-1800′ Center Ridge Wx Station-
recorded no new snow in the last 24 hours. The current temp is 19F (8 degrees colder than yesterday) with a total snowpack depth of 64 inches (1 inch of settlement since yesterday).
The weather forecast for:
WESTERN PRINCE WILLIAM SOUND-
500 AM AKST MON JAN 25 2010
…STRONG WIND THIS MORNING NEAR WHITTIER…
.TODAY…MOSTLY SUNNY. PATCHY MORNING FOG. HIGHS IN THE LOWER 20S TO
MID 30S…COLDEST INLAND. LIGHT WINDS EXCEPT NORTH 15 TO 30 MPH NEAR
SEWARD. NEAR WHITTIER…WEST WIND 30 TO 45 MPH DIMINISHING TO 15 TO
30 MPH IN THE AFTERNOON.
.TONIGHT…INCREASING CLOUDS. LOWS 10 TO 25 ABOVE…COLDEST INLAND.
LIGHT WINDS EXCEPT NORTH AND WEST 15 TO 25 MPH NEAR SEWARD AND
.TUESDAY…MOSTLY CLOUDY. HIGHS IN THE MID 20S TO MID 30S. VARIABLE
WIND TO 10 MPH. NEAR SEWARD…NORTH WIND 15 TO 30 MPH.
.TUESDAY NIGHT…MOSTLY CLOUDY WITH ISOLATED SNOW SHOWERS. LOWS
IN THE MID TEENS TO LOWER 30S. EAST WIND 10 TO 15 MPH EXCEPT
NORTH 15 TO 25 MPH NEAR SEWARD.
TEMPERATURE / PRECIPITATION
SEWARD 29 19 31 / 0 0 0
GIRDWOOD 20 15 26 / 0 0 0
Today the avalanche hazard remains at LOW with pockets of MODERATE danger on slopes steeper than 35 degrees. Snow conditions currently consist of 1-2 feet of settled powder on top of a slick crust that formed in early January. Although I would expect any avalanches triggered to be small and not propagate very far, isolated pockets of sensitive soft slab 1-2 feet deep do exist on steep slopes and were reactive as recently as Saturday.
We ran into many tired happy people yesterday and for good reason. Only a couple reports of small human-triggered slides have made it our way the last few days. Last Thursday, a skier kicked off a small 1 ft. deep soft slab that slid on a hard bed surface on Cornbiscuit. Saturday afternoon several folks noticed a new skier-triggered soft slab on the west face of Magnum at 2500 feet. This slide was estimated at 30-50 feet wide, 1 ft. deep, and 150 feet long. CNFAIC Staff than sluffing on 40+ degree terrain, no CNFAIC Staff recent avalanche activity has been reported. Folks are skiing and riding big lines without incident.
During our tours this past weekend, we observed no obvious signs of instability, and ski cuts did not trigger any soft slabs. We continue to get moderate to hard shears 1-2 feet down on top of the buried crust (CT14-24 all Q2’s). CNFAIC Staff than a few isolated pockets, our current snowpack lacks the energy to propagate a fracture, but that could quickly change with the addition of new or windblown snow. The fact is we have a significant buried weak layer that could become active again with more of a snowload. In the trees below 1500 feet north of Tincan yesterday, one of our observers reported hearing a loud whumph when he was climbing out of a gully onto a wind pillow. He did not see any fracture lines in the vicinity even though it knocked the snow off the surrounding trees. My guess is the snow collapsed underneath the crust on buried surface hoar and facets.
If big lines are on your agenda, evaluate the snow and terrain carefully. Travel one at a time, watch your partner, have an escape route, avoid terrain traps, and have a rescue plan with all the rescue equipment needed for companion rescue. In the backcountry you are the rescue party. Always remember that safe backcountry travel requires training and experience. You control your own risk by choosing where, when, and how you travel.
**Do you or any of your friends have an opinion on whether or not there should be current avalanche information available for the Front Range section of Chugach State Park? If so, please take 5 minutes to contribute to the process by filling out the survey below. This information will be used to determine if such a program is feasible or not. Only one survey per computer is allowed, but anyone can fill it out if an un-used computer is accessed. Click here to take survey
Matt 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.