Turnagain Pass Avalanche Forecast

Good morning backcountry travelers this is Carl Skustad with the Chugach National Forest Avalanche Information Center on Saturday January 16th 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

Over the years I’ve heard many snowmachiners ask for a snowmachine avalanche workshop. Well it’s here, next weekend. Sat the 23 and Sun the 24 in Turnagain Pass. Check it out at Alaska Avalanche School alaskaavalanche.com or call (907) 345-0878. This is the real deal with rescue procedures and snow assessments, some class room and lots of field work. Know Before You Go.

WEATHER ROUNDUP

3800′ -Sunburst Wx Station-

21 degrees F with moderate average winds from 10-17 and gust of 22-28 out of the east.

2400′-Seattle Ridge Wx Station-

Moderate east winds averaging 6-14 with gusts of 10-24.

1800′-Center Ridge Wx Station-

27 degrees and 6 new inches of snow in the past 24 hours. .5 inches of water equivalent.

Summit Lake

27 degrees and 1 inch of new snow. .1 inch of water equivalent.

Fresno Ridge

21 degrees and increasing winds. Strong average winds from 10 to 23 with gusts 15 – 30 out of the southeast.

1 inch of snow fell here in the Girdwood Valley last night while midway on Alyeska received 2-3 inches and Turnagain got 6 inches. The radar and satellite show scattered snow over Prince William Sound with a more significant band of precip just entering the Middleton Radar from the SE. A large 970 mb low is positioned to our SE and has the NWS guessing this morning. The models are uncertain of the storms exact path and precip amounts have limited certainty. The models I reviewed have the bulk of the precip heading west toward Yakatat and anCNFAIC Staff band heading north into the Cooper River Delta. Short Term Weather Model Forecasts (NAM, WRF, GFS) for the Kenai Mountains near Turnagain Pass , Sea-level: GFS shows additional snow or rain mix starting at 1000 and ending at midnight.

Forecast

AKZ125-170100-

WESTERN PRINCE WILLIAM SOUND-

INCLUDING…WHITTIER…SEWARD…GIRDWOOD…MOOSE PASS

500 AM AKST SAT JAN 16 2010

.TODAY…SNOW IN THE MORNING…THEN SNOW AND RAIN IN THE

AFTERNOON. SNOW ACCUMULATION 2 TO 5 INCHES. HIGHS IN THE LOWER

30S TO LOWER 40S. NORTH AND EAST WIND 10 TO 20 MPH.

.TONIGHT…SNOW AND RAIN. SNOW ACCUMULATION UP TO 3 INCHES. LOWS

IN THE UPPER 20S TO MID 30S. NORTHEAST WIND 15 MPH INCREASING TO

EAST 15 TO 30 MPH AFTER MIDNIGHT.

.SUNDAY…SNOW AND RAIN. SNOW ACCUMULATION UP TO 4 INCHES IN THE

HIGHER ELEVATIONS. HIGHS IN THE UPPER 20S TO UPPER 30S. EAST WIND 15

TO 30 MPH.

.SUNDAY NIGHT…SNOW. LOWS IN THE MID 20S TO MID 30S. SOUTHEAST WIND

15 MPH.

.MARTIN LUTHER KING JR DAY…RAIN LIKELY. HIGHS IN THE MID 30S TO

LOWER 40S. VARIABLE WIND 10 MPH.

.MONDAY NIGHT…SNOW AND RAIN LIKELY. LOWS 25 TO 35.

.TUESDAY AND TUESDAY NIGHT…MOSTLY CLOUDY WITH A CHANCE OF SNOW.

HIGHS 25 TO 35. LOWS IN THE 20S.

TEMPERATURE / PRECIPITATION

SEWARD 37 30 34 / 100 80 80

GIRDWOOD 42 35 39 / 100 80 80

AVALANCHE DISCUSSION

Will last nights six inches of snow increase today’s avalanche hazard? Yes, I think we have to start thinking in this direction. With 10 – 16 inches of total snowfall this week resting on top of a rain crust our avalanche hazard will increase to MODERATE today.

MODERATE is defined as heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Natural avalanches unlikely, human-triggered avalanches possible. Small avalanches in specific areas; or large avalanches in isolated areas.

Depending on the amount of precipitation we receive this weekend, the avalanche hazard will most likely increase in our advisory area. Summit Lake received much less snow this week and only an inch last night, the avalanche hazard there will remain lower today. In either area the addition of rain, snow, or strong winds will add stress to a snowpack that’s resting on our weakest layer to date this season.

The first human triggered avalanche was reported from 3800 ft on Pastoral two days ago. This should remind all of us that we are leaving the slack, low hazard, time period behind. The band of elevation I’m most concerned with lies from 2000 to 3000 ft where the rain left a thin crust last week. This crust is now buried up to 16 inches in some places, deeper if wind deposited snow exists. One trap we need to avoid is finding good quality and stable snow above 3000 feet then getting sucked into a big line that cruises into this less stable snow band. In some cases the effect of the rain went higher than 3000 ft.

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 17th.