Turnagain Pass Avalanche Forecast

GENERAL ANNOUNCEMENTS

Good Morning backcountry travelers, this is Carl Skustad with the Chugach National Forest Avalanche Information Center on Saturday, February 14, 2009 at 7am. This will serve as a general backcountry avalanche advisory issued 5 days a week Wednesday-Sunday for the Turnagain Arm area (Turnagain Pass is the core advisory area). Local variations always occur.

I will be at the BLM Cambell Creek Science Center Winter Trails Day today, come on out and learn about winter recreation and equipment, it’s free. Also, Dean Cummings and H20 Guides will be holding a RECCO demo and a Be Snow Safe program at Alpin Glow today, I don’t have much info on that one.

MOUNTAIN WEATHER ROUND UP

In the last 24 hours…

-General Weather Observations-

Warmer temps again this morning. 33-35 deg at see level and 18 deg F at interior ridge tops. Winds were strong with gust out of the east up to 50 mph in the alpine. Snow, rain, and wind is forecasted.

–The DOT weather station near the crest the highway at Turnagain Pass at 1000 feet–

Is recording a temp of 30 degrees (2 deg cooler than yesterday) with NE winds measuring 5 mph.

–The NRCS Center Ridge weather station at 1800 feet in Turnagain Pass–

Has a temp of 26 degrees (same as yesterday). Turnagain Pass did receive 2 inches of snow Wednesday night, and one inch yesterday. Total snowpack is 65 inches.

–The Sunburst weather station at 3800 feet in Turnagain Pass–

Shows a temperature of 18 degrees (1 deg cooler than yesterday). Winds have been strong since yesterday morning. They have currently dropped into the teens from the east.

-Surface Analysis Maps-

A 972 mb low is moving into the Cook Inlet this morning from the east bringing with it precip.

-Radar-

A rain snow squall is located in central PWS, and anCNFAIC Staff in the Cook Inlet. Not major players, but will provide scattered snow and rain showers with a potential blue sucker hole to clear skies in between systems.

AVALANCHE HAZARDS

Primary avalanche concerns

-New wind blown snow forming surface wind slabs on slippery bed surface on alpine ridges above 3000 feet

Secondary avalanche concerns

-Rain crust from January hurricane below 3000 feet.

AVALANCHE AND SNOWPACK

Bottom Line

Extra Caution is advised again today. Expect moderate avalanche hazard in most areas today with pockets of considerable near ridge tops. Human triggered avalanches are probable and natural avalanches are possible in these wind loaded pockets near ridge tops, side loaded gullies, convex roll-overs, and steep wind effected slopes over 35 degrees.

Discussion

Warmer temps, new snow, and lots of wind means we have an upside down surface snowpack. Very cold clear conditions last week created light density, faceted snow. The small amount of new snow we received and wind has put heavier snow on top of this light snow. The wind has also given the current snow surface some energy. You may start seeing shooting cracks in the alpine snowpack and on wind effected convex roll-overs.

The size of avalanches today will be small in the lower elevations and larger adjacent to alpine ridges. More snow fell in Girdwood than did in Turnagain Pass. 4-6 inches in the last couple of days vs. 1-3!

WEATHER FORECAST

WESTERN PRINCE WILLIAM SOUND-

INCLUDING…WHITTIER…SEWARD…GIRDWOOD…MOOSE PASS

500 AM AKST SAT FEB 14 2009

.TODAY…SNOW LIKELY IN THE MORNING…THEN SCATTERED SNOW SHOWERS

IN THE AFTERNOON. SNOW ACCUMULATION UP TO 2 INCHES…MAINLY ALONG

THE SOUND. HIGHS IN THE 30S. SOUTH TO EAST WIND 10 TO 20 MPH.

.TONIGHT…CLOUDY WITH A SLIGHT CHANCE OF SNOW SHOWERS IN THE

EVENING…THEN SNOW SHOWERS AFTER MIDNIGHT. SNOW ACCUMULATION

UP TO 2 INCHES. LOWS IN THE UPPER 20S TO MID 30S. SOUTH TO EAST

WIND 10 TO 15 MPH EXCEPT EAST WIND INCREASING TO 15 TO 30 MPH

THROUGH PORTAGE VALLEY AND TURNAGAIN ARM.

.SUNDAY…SNOW…MIXING WITH RAIN NEAR SEA LEVEL IN THE AFTERNOON.

SNOW ACCUMULATION UP TO 3 INCHES. HIGHS IN THE 30S. SOUTH TO EAST

WIND 10 TO 25 MPH EXCEPT EAST 25 TO 40 MPH THROUGH PORTAGE VALLEY

AND TURNAGAIN ARM.

.SUNDAY NIGHT…SNOW AND RAIN. LOWS IN THE MID 20S TO LOWER 30S.

EAST WIND 10 TO 25 MPH. THROUGH PORTAGE VALLEY AND TURNAGAIN

ARM…EAST WIND 35 TO 45 MPH INCREASING TO 45 TO 60 MPH AFTER

MIDNIGHT.

This concludes today’s avalanche advisory the next advisory will be on Sunday, February 15th. Thanks and have a great day.