Good morning backcountry travelers this is Jon Gellings with the Chugach National Forest Avalanche Information Center on Thursday, January 27th 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).
The Friends of the CNFAIC (FCNFAIC) needs your thoughts! With a new staff of forecasters and a list of previously completed goals, the program is growing and potentially heading in new directions. The FCNFAIC wants to know what you have to say about YOUR avalanche center, so please complete the following anonymous survey by February 20th. All information gathered will be discarded after that time. You do not need to answer all the questions, but the more complete the survey is, the better the data will be. This survey will be located here for a week, and will then be relocated to the bottom of the advisory for the remainder of the open period. Thank you in advance for taking it!
Click here to take survey
The avalanche danger rating today remains at MODERATE. Naturally triggered avalanches are unlikely, but Human triggered avalanches are still Possible in steep windloaded terrain at higher elevations. If somebody does trigger an avalanche, the size of the slide could become large enough to bury, injure, or kill a human.
The most recent human triggered avalanche we have information on happened on Monday. A snowmachiner triggered and got caught in an avalanche down by Lost Lake, but was dug out expediently by his partner. Limited details about the avalanche include:
-30-40 degrees steep
-2000 ft elevation
-Failed 2-3 feet deep
-Monday, which had a Considerable Danger rating
Thankfully the rider was uninjured, and the riding partner was good at shoveling, which is the most time consuming part of a rescue. Please remember that the majority of fatalities occur on days of Moderate and Considerable Danger; Today is one of those Moderate days. This is because the danger is very apparent during High and Extreme danger periods, while Moderate and Considerable days tend to show less obvious amounts of instability. Please be careful when out recreating, because getting hurt is never fun. A question everybody can ask themselves from this incident is, “Who am I travelling with, and would they be able to dig me out of an avalanche?”
Yesterday, we finally had some good visibility, so we were able to see a few previously unseen natural avalanches. These had occurred on the South Face of Tincan, South Face of Sunburst, West Face of Magnum, East Face on the South end of Seattle Ridge, South Face of Petes South, and on Captains Chair near Lynx Creek. We were able to check out the avalanche at 3300ft in “Hippie Bowl” on the South Face of Tincan, and our thoughts are that the avalanche failed during the height of the storm on Monday Night or Tuesday Morning. It failed about a foot down on some mid-storm interface, far above the old snow/new snow interface. While our week-long storm gave us 24-28 inches of upside-down snow at 1800ft, it deposited much higher amounts in upper elevation areas like this one.
We also received some great observations from public users. Thank you so much! One person stated that the 15th person skinning up Sunburst felt a collapse right before it reaches the ridgeline. AnCNFAIC Staff person performed compression tests on Tincan at 2800ft on a 36deg slope, and stated that within the top meter of snow, he got moderate to high strength failures, with low to moderate energy.
Our recent storm has buried numerous types of significant weak layers. Widespread surface hoar that formed January 5-18 is the easiest to find at lower elevations, and will likely be in these snowpits for a long time. The new snow that fell is also sitting on top of CNFAIC Staff variable conditions, including ice crusts, wind crusts, wind slabs, and sugary facets. These, combined with our older instabilities like buried surface hoar from December, as well as facets above and below the Thanksgiving Rain Crust, could still be re-energized by a large storm. Step downs to deeper instabilities could happen with any new avalanche, so prepare for the worst and make sure you are ready in case something happens.
Encyclopedia of terms: www.fsavalanche.org/Encyclopedia.aspx
Radar images currently show a minimal amount of precipitation over Prince William Sound, while satellite images show partly cloudy skies in our area right now. It looks like we are about to miss out on a fairly strong storm, which is currently a 956mb Low Pressure “Pineapple Express”. NWS forecasts, discussions, and models all show it moving North into the Bering Sea, so our local snowpack will probably not be feeling a huge jolt from this in the near future. Winds have died down to nearly stagnant, while temps have decreased into the upper teens at higher elevations.
Kevin 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 THU JAN 27 2011
.TODAY…MOSTLY CLOUDY. ISOLATED SNOW SHOWERS INLAND IN THE MORNING.
HIGHS IN THE LOWER 20S TO LOWER 30S. LIGHT WINDS EXCEPT WEST
15 TO 30 MPH NEAR WHITTIER AND NORTH WIND 10 TO 20 MPH NEAR SEWARD.
.TONIGHT…PARTLY CLOUDY. LOWS 15 TO 25. EAST WIND 10 TO 15 MPH.
.FRIDAY…MOSTLY CLOUDY. HIGHS IN THE LOWER 20S TO LOWER 30S…
COOLEST INLAND. VARIABLE WIND TO 10 MPH. NEAR WHITTIER…LIGHT WINDS
BECOMING EAST 10 TO 15 MPH IN THE AFTERNOON.
TEMPERATURE / PRECIPITATION
SEWARD 31 24 31 / 0 0 0
GIRDWOOD 31 19 25 / 20 0 0
WEATHER STATION SUMMARY for Turnagain Pass:
-3800′ Sunburst Wx Station-
recorded winds yesterday averaging 4-8mph. Temperatures were recorded from 20F to 24F. There are calm winds with a temperature of 18F currently.
-2600′ Seattle Ridge Wx Station-
is currently not recording winds; We will hopefully fix this today. Temps recorded 27F to 22F yesterday. Temp is currently 20F.
-1800′ Center Ridge Wx Station-
recorded 3 inches of light density new snow, with .1 inch SWE in the last 24 hours. The snowpack settled 4 inches, gained 3, and then settled 1 inch, bringing the total snow depth to 78 inches. Temps yesterday recorded from 25F to 34F during the day. The current temp is 23F.