Turnagain Pass

Good morning backcountry travelers. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Sunday, April 10th 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).

BOTTOM LINE

The avalanche danger is MODERATE on slopes steeper than 35 degrees for persistent slab avalanches. These will be possible to trigger at the mid to upper elevations and requires a heads up. Also, human triggered wet loose snow avalanches are possible during the afternoon on southerly slopes as the snow softens up.

AVALANCHE DISCUSSION

The only new avalanche activity seen or reported from yesterday was wet loose sluffing with daytime heating. The sun has had its way with snow surface over the past two days and most aspects and elevations will sport a sun crust again this morning. If the clouds do not limit the heating today the crusts should soften to varying degrees for better riding but this also increases the avalanche danger.

Persistent slab avalanches are again the primary concern for today. This is a heads up snowpack right now. These types of avalanches have been less reactive the past couple days and snowpack analyses are showing both good and bad results. However, this does not mean a person will not be able to find a slope waiting for the right trigger.

Collapsing, hearing ‘whoomphing’ noises or seeing shooting cracks are bulls eye clues that there is some ‘funny business’ going on underneath the snow surface (i.e. buried surface hoar). These are most prone on mid to upper elevation steeper slopes with the danger peaking with the heat of the day as any sun crusts soften. Also, be especially wary venturing along ridgelines or near slopes that have not had human traffic for several days or longer.

If the sun stays out today and winds remain calm, keep an eye out for the snow to become saturated on east,west and south slopes. Human triggered wet sluffing should be possible to initiate which could entrain quite a bit of snow and run far on the underlying crusts. Also, with the warm temperatures loosening the snow, cornices deserve a wide berth.

Photos from last week (here and here) just sent in of a snowboarder caught and carried in Seattle Creek.

Outside of our advisory area:

There was a remotely triggered avalanche in the Hatcher Peak area yesterday. Details HERE.

Encyclopedia of avalanche terms.

WEATHER ROUNDUP

Yesterday we had mostly clear skies, warm temperatures near 30F on the ridgelines and low 40’s near 1000′ with very light ridge top winds. Overnight a few clouds moved in and temperatures dropped only into the mid 20’s at most locations. Today we should see partly cloudy skies with a slight chance for scattered precipitation to move through with no accumulation. Temperatures should approach 30F around 3500′ and near 40F at 1000′. Expect winds to remain light from the northeast with gusts around 10mph on the ridge tops.

I 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 AKDT SUN APR 10 2011

.TODAY…MOSTLY CLOUDY WITH RAIN SHOWERS…MIXING WITH SNOW IN THE

MORNING. HIGHS IN THE LOWER 40S TO LOWER 50S. LIGHT WINDS.

.TONIGHT…MOSTLY CLOUDY. ISOLATED RAIN SHOWERS IN THE EVENING…

THEN SCATTERED SNOW SHOWERS AFTER MIDNIGHT. LOWS IN THE MID 20S TO

LOWER 30S. LIGHT WINDS.

.MONDAY…MOSTLY CLOUDY WITH SCATTERED SNOW AND RAIN SHOWERS. HIGHS

IN THE UPPER 30S TO MID 40S. LIGHT WINDS.

.MONDAY NIGHT…MOSTLY CLOUDY. SCATTERED RAIN SHOWERS IN THE

EVENING…THEN SCATTERED SNOW SHOWERS AFTER MIDNIGHT. LOWS IN THE

LOWER 20S TO LOWER 30S. LIGHT WINDS.

.TUESDAY…MOSTLY CLOUDY. SCATTERED SNOW SHOWERS IN THE MORNING…

THEN SCATTERED RAIN SHOWERS IN THE AFTERNOON. HIGHS IN THE

UPPER 30S TO MID 40S. VARIABLE WIND 10 MPH.

.TUESDAY NIGHT…PARTLY CLOUDY WITH ISOLATED RAIN AND SNOW SHOWERS.

LOWS IN THE 20S.

.WEDNESDAY…MOSTLY SUNNY. HIGHS 35 TO 45.

TEMPERATURE / PRECIPITATION

SEWARD 43 31 43 / 20 40 40

GIRDWOOD 46 25 41 / 30 40 40

WEATHER STATION SUMMARY for Turnagain Pass:

-3800′ Sunburst Wx Station-

Currently 21 degrees. Wind light variable.

-2600′ Seattle Ridge Wx Station-

Currently 23 degrees. Wind light variable.

-1800′ Center Ridge Wx Station-

Currently 27 degrees. No new snow.