Turnagain Pass

Good morning backcountry travelers this is Carl Skustad with the Chugach National Forest Avalanche Information Center on Saturday, January 30 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).

ANNOUNCEMENTS

!FREE! Avalanche Education in Anchorage today from the Alaska Avalanche School.

Avalanche Awareness Lecture Series

(No Registration Required)

WHEN: Saturday Jan. 30, 2010

Time: Seating and sign in begins at 8:45am. Lecture runs from 9:00am to 1:00pm

WHERE: Alaska Pacific University Carr-Gottstein Building, Room 102

4101 University Drive Anchorage AK

DURATION: The Lecture has a run time of 4 Hours

with intermittent breaks throughout.

COST: FREE!!

Avalanche Field Workshop

(Registration is Required: Please Contact the Office to Enroll)

By Popular Demand there are 2 Avalanche Field Workshops

WHEN:Morning Program: Sunday, January 31, 2010: 9:00 am to 1:00 pm

Afternoon Program: Sunday, January 31, 2010: 1:30 pm to 5:30 pm

WHERE:Glen Alps Trail Head (Flat Top Parking Lot)

Chugach State Park

DURATION:Each program will run 4 hours. Please be ready to spend the duration of the program outside.

COST:FREE

WEATHER ROUNDUP

3800′ -Sunburst Wx Station-

Current temp is 32 (6 degrees warmer than yesterday). Winds dropped below 10 mph yesterday afternoon. Current winds are light, 3 mph with gusts of 5-8.

2400′-Seattle Ridge Wx Station-

Winds are light 0 to 2 with gust of 2-6

1800′-Center Ridge Wx Station and 0 new water.

Temperatures are very warm again this morning. 3 of our ridge top stations are above freezing. The Center Ridge weather station hit 38 degrees yesterday at 1200. The radar shows fairly clear skies and the satellite show high clouds clearing our of the area. Warm temps and the potential for partly clear skies makes this a heads up avalanche day.

Forecast (National Weather Service)

WESTERN PRINCE WILLIAM SOUND-

INCLUDING…WHITTIER…SEWARD…GIRDWOOD…MOOSE PASS

500 AM AKST SAT JAN 30 2010

.TODAY…PARTLY CLOUDY IN THE MORNING THEN BECOMING MOSTLY CLOUDY. PATCHY MORNING FOG. HIGHS IN THE 30S. LIGHT WINDS EXCEPT NORTH 10 TO 15 MPH NEAR SEWARD.

.TONIGHT…MOSTLY CLOUDY. PATCHY FOG AFTER MIDNIGHT. LOWS IN THE LOWER 20S TO LOWER 30S. LIGHT WINDS EXCEPT NORTH 15 TO 20 MPH NEAR SEWARD.

.SUNDAY…MOSTLY CLOUDY. HIGHS IN THE 30S. EAST WIND 10 TO 15 MPH EXCEPT NORTH 10 TO 15 MPH NEAR SEWARD.

.SUNDAY NIGHT…MOSTLY CLOUDY. LOWS IN THE LOWER 20S TO LOWER 30S. VARIABLE WIND 10 MPH. .MONDAY…CLOUDY. HIGHS IN THE UPPER 20S TO MID 30S. EAST WIND 10 TO 15 MPH. .MONDAY NIGHT…MOSTLY CLOUDY. LOWS IN THE 20S. .TUESDAY…MOSTLY CLOUDY WITH A CHANCE OF SNOW. HIGHS 25 TO 35. .TUESDAY NIGHT…PARTLY CLOUDY. LOWS IN THE 20S. .WEDNESDAY THROUGH THURSDAY…MOSTLY CLOUDY WITH A CHANCE OF SNOW. HIGHS IN THE 20S. LOWS IN THE TEENS. .THURSDAY NIGHT AND FRIDAY…MOSTLY CLOUDY WITH A CHANCE OF SNOW. LOWS IN THE TEENS. HIGHS 15 TO 25.

TEMPERATURE / PRECIPITATION

SEWARD 36 26 34 / 0 0 0

GIRDWOOD 36 25 37 / 0 0 0

AVALANCHE DISCUSSION

Today’s avalanche hazard will remain at MODERATE. Yesterday, we toured up Tincan in Turnagain Pass and found 4-6 inches of new snow that fell Wednesday and Thursday, 10 inches in wind deposited areas. We found very warm temperatures and skin sticking snow snow all the way to 3500 feet. We also found easy failures on the new snow old snow interface. This should tighten up over time but was somewhat sensitive yesterday. Skiers found this sensitive layer yesterday on Superbowl and the south side of Cornbiscuit where they triggered two separate avalanches. Both were on southerly aspects around 3600 to 3700 ft. They measures 10 inches deep, 45-60 ft wide and ran 700 to 900 ft. I believe they failed on the old snow, new snow interface I described above in wind deposition areas. This weak interface has buried surface hoar associated with it in many areas up to 3000ft.

This type of avalanche will be possible again today. Very warm temperatures are settling our new snow into a consolidated slab. This slab is much denser than the light density snow under it. Clues that you are on a slab include shooting cracks and hollow sounds under ski or track.

If the temperatures reach the upper 30’s and the sun comes out again the avalanche danger will increase to CONSIDERABLE on sun effected aspects, this means natural avalanches are possible and human triggered avalanches are likely. Yesterday, we witnessed solar triggered loose snow avalanches on south facing aspect. If these loose snow avalanches entrain enough snow they could trigger larger avalanche activity.

I believe the Upper Girdwood and Placer River Drainage above the snow line received a couple more inches of snow than Turnagain Pass did. This would increase the depth and size of any slab avalanche activity.

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 advisory will be posted tomorrow Sunday, January 31st.