CNFAIC LogoCNFAIC Logo

Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   CNFAIC Staff  
Monday, February 22nd 2010
Created: Feb 22nd 6:43 am
3 Considerable Above Treeline
Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential. Likelihood of Avalanches: Natural avalanches possible; human-triggered avalanches likely. Avalanche Size & Distribution: Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
3 Considerable Below Treeline
Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential. Likelihood of Avalanches: Natural avalanches possible; human-triggered avalanches likely. Avalanche Size & Distribution: Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
 Show the Complete North American Avalanche Danger Scale
Subscribe to the Turnagain Area Avalanche Advisory:
The Bottom Line
Good morning backcountry travelers this is Lisa Portune with the Chugach National Forest Avalanche Information Center on Monday, February 22nd 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).

WEATHER ROUNDUP
No new snow fell in the last 48 hours in Turnagain Pass. Under cloudy skies yesterday, winds averaged 5-25mph out of the east while mountain temps ranged from the upper 20s at 3800 feet to low 40s at 1800 feet. Temperatures have cooled off slightly this morning but are still well above average, ranging from 30F@sea level to 35F@1800 to 30F@3800. Its worth mentioning that temperatures have been above freezing at the mid elevations for at least the last four days, and in some areas the last seven days. Skies are clear this morning, and ridgetop winds are light averaging 10-15mph out of the east. Looks like we have a pretty nice day in store today before the next low moves into the region tomorrow. Expect partly cloudy skies, continued warm temps in the upper 20s to upper 30s, and moderate easterly winds averaging 15-25mph.

AVALANCHE DISCUSSION
Today the avalanche danger remains CONSIDERABLE. Human-triggered avalanches are likely on slopes steeper than 35 degrees while natural avalanches will be possible on south facing sun-affected slopes. The biggest storm of the season ended only 3 days ago, bringing 7.5 feet of snow and 9 inches of water to Turnagain Pass. Although we are well past the apex of the natural avalanche cycle (Feb. 18), the avalanche hazard remains elevated due to four straight days of unusually warm temperatures. Our main concerns today are sensitive windslab at the higher elevations and wet slab avalanches at the mid and lower elevations, especially on south facing slopes.

Below freezing temperatures above 3000 feet have helped to stabilize the new snow, but Fridays high winds left us with some sizeable windslabs and a somewhat windhammered snowpack up high. Shooting cracks and hollow hardslab were reported near ridgetops yesterday. Of greater concern is the possibility of wet slab avalanches on south facing slopes and at the mid elevations where the snowpack remains saturated. Rollerballs, pinwheels, and point-release sluffs are all indications that the surface snow is unstable and that it is time to get off the slope.

The big unknown right now is the condition of our deep slab instabilities, most notably several layers of buried surface hoar and the Jan. 7 rain crust. Numerous large natural and explosive-triggered avalanches ran on the deeply buried Jan. 7 rain crust during this latest storm. And the buried surface hoar was responsible for many natural and human-triggered slides before the storm really got cranking. Im guessing that a majority of the natural avalanches that happened during the storm ran on or stepped down to these layers. Avalanches triggered today could possibly step down to these deep weak layers, creating a much larger avalanche.

We received a report of new glide cracks forming in the upper Girdwood Valley (2200 feet on Raggedtop) that opened up noticeably since Saturday. Cornices were also noted to be sagging, probably from the April-like temperatures the last 4 days. As always, give both glide cracks and cornices a wide berth.

Matt 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 MON FEB 22 2010

.TODAY...MOSTLY CLOUDY WITH AREAS OF FOG IN THE MORNING. PARTLY
CLOUDY IN THE AFTERNOON. HIGHS IN THE MID 30S TO LOWER 40S. EAST WIND
10 TO 20 MPH.
.TONIGHT...MOSTLY CLOUDY. SCATTERED SNOW SHOWERS AFTER MIDNIGHT. LOWS
IN THE MID 20S TO MID 30S. EAST WIND 10 TO 20 MPH.
.TUESDAY...CLOUDY. A CHANCE OF SNOW IN THE MORNING...THEN A CHANCE OF
SNOW AND RAIN IN THE AFTERNOON. HIGHS IN THE MID 30S TO LOWER 40S.
EAST WIND 10 TO 15 MPH.
.TUESDAY NIGHT...SNOW LIKELY. LOWS IN THE MID 20S TO MID 30S.
LIGHT WINDS EXCEPT NORTH 10 MPH NEAR SEWARD.
.WEDNESDAY...RAIN AND SNOW LIKELY. HIGHS IN THE MID 30S TO LOWER 40S.
LIGHT WINDS EXCEPT NORTH 10 MPH NEAR SEWARD.

TEMPERATURE / PRECIPITATION

SEWARD 39 32 39 / 10 30 40
GIRDWOOD 38 28 37 / 0 30 30


WEATHER STATION SUMMARY for Turnagain Pass:
-3800 Sunburst Wx Station-
recorded light easterly winds yesterday averaging 5-15mph. The current temp is 30F (1 degree colder than yesterday) with winds averaging 13mph out of the east.

-2600 Seattle Ridge Wx Station-
recorded moderate southeasterly winds yesterday averaging 15-25mph with gusts to 36mph. Winds are currently averaging 15mph out of the southeast this morning.

-1800 Center Ridge Wx Station-
recorded no new snow in the last 24 hours. The current temp is 35F (2 degrees colder than yesterday) with a total snowpack depth of 93 inches (3 inches of settlement since yesterday, 21 inches settlement since 2/18). The temperature has been above freezing for the last four days.

This is 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).

Winter snowmachine use open/closed status and riding conditions updates

Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.

(Updated: Apr 29, 2014 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: Closed
Placer River: Closed
Skookum Drainage: Closed
Turnagain Pass: ClosedClosed as of April 23rd.
Twentymile: Closed
Seward District
Carter Lake: Closed
Lost Lake Trail: Closed
Primrose Trail: Closed
Resurrection Pass Trail: Closed
Snug Harbor: OpenPlease stay on existing road (and snow) bed to gain access into Lost Lake. Snug Harbor will be closing to snowmachines on May 1st.
South Fork Snow River Corridor: Closed
Summit Lake: Closed

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur. This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.


USFS SNOW AND AVALANCHE HOTLINE (907) 754-2369
If you have comments regarding CNFAIC operations or winter recreation management, please email kevin@chugachavalanche.org
© 2014 Chugach National Forest Avalanche Information Center. All rights reserved.
FCNFAIC
Donate
If you think a public avalanche
center is important then we urge
you to become a member & donate.


PickClickGive



By clicking the links below, the companies will donate a portion of your purchase price to the Friends of CNFAIC. Click here for more deals