Turnagain Pass Avalanche Forecast

Good morning backcountry travelers this is Carl Skustad with the Chugach National Forest Avalanche Information Center on Saturday January 9th at 7 am. 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).

WEATHER ROUNDUP

3800′ -Sunburst Wx Station-Turnagain Pass

29 deg F, winds are averaging 16-17 with gusts 23-26 out of the E

2400′-Seattle Ridge Wx Station-Turnagain Pass

winds averaging 11-14 with gusts 17-22 out of the E

1800′-Center Ridge Wx Station-Turnagain Pass

Precip: 0 inches of water and 0 new snow

Total depth of 56 inches

Temperatures ranged from 32-36 degrees F, current temp is 35

Summit Lake

Precip: 0 inches of water and 0 new snow

Total depth of 29 inches

Temperatures ranged from 23-33 degrees F, current temp is 31.6

3440′ – Fresno Ridge – Summit Lake Area

30.6 deg F, winds averaging 12-23 with gusts to 33 mph out of the WSW

Weather Forecast

AKZ125-100100-

WESTERN PRINCE WILLIAM SOUND-

INCLUDING…WHITTIER…SEWARD…GIRDWOOD…MOOSE PASS

500 AM AKST SAT JAN 9 2010

.TODAY…RAIN AND SNOW SHOWERS DIMINISHING THIS AFTERNOON.

CNFAIC StaffWISE…MOSTLY CLOUDY. SNOW ACCUMULATION 1 INCH OR LESS. HIGHS IN

UPPER 20S TO LOWER 40S…COLDEST INLAND. VARIABLE WIND TO 15 MPH.

NEAR SEWARD…NORTH WIND 10 TO 25 MPH.

.TONIGHT…SCATTERED RAIN AND SNOW SHOWERS IN THE EVENING.

CNFAIC StaffWISE…DECREASING CLOUDS. LOWS IN THE LOWER TEENS TO LOWER

30S… COLDEST INLAND. LIGHT WINDS EXCEPT NORTH TO 30 MPH NEAR

SEWARD.

.SUNDAY…MOSTLY SUNNY. HIGHS IN THE LOWER 20S TO MID 30S…

COLDEST INLAND. LIGHT WINDS EXCEPT NORTH 30 MPH NEAR SEWARD AND WEST

20 MPH NEAR WHITTIER.

.SUNDAY NIGHT…PARTLY CLOUDY WITH A SLIGHT CHANCE OF SNOW. LOWS

5 TO 25 ABOVE…COLDEST INLAND. LIGHT WINDS EXCEPT NORTH 30 MPH NEAR

SEWARD AND WEST 20 MPH NEAR WHITTIER.

.MONDAY…MOSTLY CLOUDY WITH A SLIGHT CHANCE OF SNOW. HIGHS IN

THE UPPER 20S TO MID 30S. VARIABLE WIND 10 MPH EXCEPT NORTH 10 TO

25 MPH NEAR SEWARD.

TEMPERATURE / PRECIPITATION

SEWARD 35 28 33 / 70 20 0

GIRDWOOD 29 16 25 / 40 0 0

The radar and satellite show clear skies currently. The Middleton radar has a large band of precipitation heading our way for mid day. This was a similar setup yesterday and skies remained clear and sunny over our advisory area. A 5 degree F inversion is in place over the Girdwood Valley this morning and a slight 1 degree inversion over Summit Lake.

AVALANCHE DISCUSSION

Today’s avalanche danger will remain at MODERATE in the alpine above 2500ft. MODERATE is defined as: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Natural avalanches unlikely (except glide cracks are possible) and human triggered avalanches possible. Small avalanches in specific areas; or large avalanches in isolated areas.

Below 2500 ft the avalanche danger is LOW. Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Jon and I got some good observations from Turnagain Pass yesterday. The rain line looks like it made it up to 3000 feet. Our pit at 3400 ft still had a slight crust on the snow surface but not from true rain (see pit in photo gallery). A band of elevation is present from 2600 to 2800 ft that had rain on dry snow. In CNFAIC Staff words the Wednesday rain pushed past the previous rain line of 2000 ft up to 3000 ft. Not good for snow quality or future avalanche stability. You can’t miss this elevation, there are roller balls the size of bowling balls all over it. Roller balls are snow balls, that form when rain hits dry snow, and role down the hill. The skiing was good from 3600 to 2600 ft then it got a little challenging. If you thought last weeks boiler plate crust was hard wait till you ski, ride , or snowmachine the current teeth rattling nar below 2000 ft. Watch your sled for overheating!

The alpine continues to show an instability 6-12 inches under the snows surface. We have consistently seen this layer from T-Pass through the Summit Lake area. Upon closer evaluation I found decomposing stelar and old faceted crystals responsible for this weak layer. It has only been failing in our stability test and has not been responsive to skis, boards, or snowgos. This is; however, my main layer of concern. Alex reported finding some buried surface hoar mixed in this layer near Summit Lake yesterday.

No naturally or human triggered avalanches of concern were noticed in Turnagain Pass yesterday. Alex reported some natural avalanche activity occurred Wednesday during the rain event. He points out that travelers in the Summit Lake area may find wind sensitive wind slabs on southern aspects.

Always remember that safe backcountry travel requires training and experience. You control your own risk by choosing where, when, and how you travel.

Thanks for checking today’s avalanche advisory. The next one will be posted tomorrow Sunday, January 10th.