Turnagain Pass

Good morning backcountry travelers. This is Jon Gellings with the Chugach National Forest Avalanche Information Center on Wednesday, March 2nd 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).

BOTTOM LINE

The avalanche danger remains at MODERATE. Triggering an avalanche is still possible in steep, rocky and unsupported terrain, as well as in areas with a shallow snow pack. Any avalanche triggered also has the potential to step down into deeper weak layers, creating a much larger and more dangerous avalanche.

AVALANCHE DISCUSSION

It is well out of our advisory area, but is worth mentioning that there was an avalanche in Hatcher Pass on Monday. It happened on Microdot, and was a suspected wind slab triggered near a thin spot in the snow. Nobody was caught or buried in this slide. Turnagain Pass seems to have some of the more stable snow in the region, but we still do not have the confidence in it to drop the danger rating to LOW. Blue skies and warm temperatures with the lack of recent avalanches do not signify safe travel conditions.

There is a weak snowpack structure in most areas covered by this advisory. Sugary faceted snow around a deeply buried crust is the layer we are most worried about. However, stability tests have recently shown that the weakest layers are currently quite strong, and that there is generally good stability in Turnagain Pass. With occasional fast and clean shears, the possibility exists for any avalanche triggered to encompass a large amount of snow, but we have not been seeing much of this activity recently, so it is hard to say what size avalanche it would be. Several avalanches from last weekend in the Summit Lake area were very large, which goes to show that shallow areas outside Turnagain Pass have the potential to be more dangerous than in the Pass itself.

Although it is a standard travel practice, make sure to thoroughly check out the snow you will be travelling on, especially if you have a big objective today. Feel free to travel wherever you see fit, but be advised that stepping or riding on the wrong slope for today could prove to be very painful, if not deadly.

WEATHER ROUNDUP

Looks like more of the same weather. Winds are not anticipated to be strong enough to transport snow, temperatures do not look like they will be warm enough to weaken the upper snow layers, and new precipitation is not likely for the foreseeable future. An inversion is set up in Turnagain Pass, which is due to low amounts of mixing air (winds).

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.

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-

INCLUDING…WHITTIER…SEWARD…GIRDWOOD…MOOSE PASS

500 AM AKST WED MAR 2 2011

.TODAY…SUNNY. HIGHS IN THE LOWER 20S TO LOWER 30S. NORTH TO

WEST WIND TO 15 MPH EXCEPT NORTH WIND 15 TO 25 MPH NEAR SEWARD.

.TONIGHT…CLEAR. LOWS ZERO TO 10 ABOVE EXCEPT 10 TO 20 ABOVE

ALONG THE COAST. NORTH TO WEST WIND TO 15 MPH EXCEPT 15 TO 30 MPH

NEAR SEWARD AND WHITTIER.

.THURSDAY…SUNNY. HIGHS IN THE 20S. VARIABLE WIND 10 MPH

EXCEPT NORTH 15 TO 30 MPH NEAR SEWARD.

TEMPERATURE / PRECIPITATION

SEWARD 27 17 28 / 0 0 0

GIRDWOOD 19 6 20 / 0 0 0

WEATHER STATION SUMMARY for Turnagain Pass:

-3800′ Sunburst Wx Station-

Temperature 12 degrees. Variable winds 0-3mph, gusting to 6.

-2600′ Seattle Ridge Wx Station-

Temperature 10 degrees. Variable winds 0-3mph, gusting to 5.

-1800′ Center Ridge Wx Station-

Temperature 7 degrees. No new snow.