Turnagain Pass Avalanche Forecast RSS

Archives
ARCHIVED FORECAST - All forecasts expire after 24 hours from the posting date/time.
Issued
Sun, May 1st, 2011 - 7:00AM
Expires
Mon, May 2nd, 2011 - 7:00AM
Forecaster
Wendy Wagner
Avalanche risk The Bottom Line

Good morning backcountry travelers. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Sunday, May 1st at 7am. We are no longer issuing daily avalanche advisories for the 2010-2011 season. However, this does not mean that the avalanche season is finished.

ANNOUNCEMENTS

All winter motorized recreation areas are now closed for the winter season.

We would like send out a HUGE THANK YOU to all who have submitted observations this year. They are invaluable to us, as well as help steer this operation in the right direction.

We’d also like to thank the Friends of the CNFAIC. You are an amazing group of folks with a passion to help keep people safe in the backcountry. THANK YOU for all your support; we could not do this without you.

Additionally, we would like to thank:

-Alyeska Ski Patrol

-Alaska DOT

-Alaska Railroad

-Alaska Avalanche School

-Alaska Pacific University

-Chugach Powder Guides

-and many CNFAIC Staffs

for sharing important avalanche information to pass on to the backcountry community.

BOTTOM LINE

We have finished issuing avalanche advisories for the season. Below is a description of general springtime avalanche concerns.

AVALANCHE DISCUSSION

Wet slab avalanches:

These are very dangerous, unpredictable and un-survivable avalanches. They are common in the spring as the snowpack warms from the increase in solar energy and generally warmer temperatures. This cycle of avalanche activity typically occurs for a period of a couple weeks and is often referred to as the ‘shed cycle’ or the ‘spring melt-down’. This year, large wet slabs began to release around April 24th.

Wet slab avalanches are a complex equation. Once the snowpack warms to near freezing it becomes isCNFAIC Staffmal and water begins to percolate through the pack. This free water can lubricate the ground or rocks (glide avalanches) or impermeable layers within the snowpack (wet slabs). This spring the Thanksgiving Rain Crust is a very suspect impermeable layer. This means water percolating through the pack can accumulate on the crust and lubricate the weaker snow grains above the crust to the point the grains lose so much strength the snow above will slide. This process can occur 24/7 since it is deep in the pack and insulated from much of the daily surface melt-freeze cycle.

The take home with wet slabs: When conditions are ripe they are often not forecastable but easily triggered (natural or human) by a wet loose snow avalanche running on top of the slab. Keep an eye out for any recent activity as well as watch the weather stations for overnight above freezing temperatures or rain on snow. When uncertainty is high, conservatism is key.

Wet loose snow avalanches:

Wet snow point release slides are common in spring and can be small and manageable or large and destructive. A small wet sluff can quickly become large on slopes with any distance to run. Wet snow is heavy and once moving can entrain large quantities of snow and run far.

These slides are often in response to daytime warming and can be easily managed by the time of day. Under clear skies, the snow surface usually freezes at temperatures under 40F; the warmer the temperature the weaker the refreeze. When frozen, the snow is strong but can rapidly weaken as the surface softens with the sun. The general rule of thumb is, once the snow penetration becomes ‘boot top’ it is weak enough to slide. East slopes weaken first, then south then west. Tours are best planned with this in mind. Early starts and afternoon tail-gates are good strategies.

Storm snow avalanches:

Storm snow avalanche activity occurs during or shortly after storms. This involves typical wintertime new snow instability concerns (wind slabs and storm snow soft slabs). The usual suspects of recent avalanches, cracking and collapsing are what to watch for. A second peak in new snow activity will often occur once the sun comes out by initiating wet loose and wet slabs (usually confined to the new storm snow).

Rain on snow can trigger wet loose snow avalanches as well as wet slab avalanches. This is most prone at elevations where the snowpack as not seen rain yet.

WEATHER ROUNDUP

A quick look at our season snow numbers:

Turnagain Pass SNOTEL (1800′ on Center Ridge)

SNOW DEPTH – Roughly 60% of last year and 80% of the long term average

Remember, for all things weather see the CNFAIC weather page!

Thank you for checking the avalanche advisories this season. Have a great spring and summer!

Thanks to our sponsors!
Sun, May 1st, 2011
Alpine
Above 2,500'
No Rating (0)
Avalanche risk
Treeline
1,000'-2,500'
No Rating (0)
Avalanche risk
Below Treeline
Below 1,000'
No Rating (0)
Avalanche risk
Alpine
Above 2,500'
Avalanche risk
No Rating (0)
Treeline
1,000'-2,500'
Avalanche risk
No Rating (0)
Below Treeline
Below 1,000'
Avalanche risk
No Rating (0)
Danger Scale:
No Rating (0)
Low (1)
Moderate (2)
Considerable (3)
High (4)
Extreme (5)
Observations
Recent Observations for Turnagain Pass
Date Region Location
02/07/23 Turnagain Observation: Seattle Ridge
02/07/23 Turnagain Avalanche: Pete’s North
02/05/23 Turnagain Observation: Rookie Hill
01/31/23 Turnagain Observation: Johnson Pass area
01/29/23 Turnagain Observation: Tincan Backdoor
01/28/23 Turnagain Observation: Sunburst
01/28/23 Turnagain Avalanche: Seattle Ridge
01/28/23 Turnagain Observation: Tincan Common
01/27/23 Turnagain Observation: Sunburst
01/27/23 Turnagain Avalanche: Lynx Creek
Riding Areas
Updated Fri, January 06th, 2023

Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: mailroom_r10_chugach@fs.fed.us

Area Status Weather & Riding Conditions
Glacier District
Johnson Pass
Open
Opened Dec 13th.
Placer River
Closed
Closed Jan 5th due to lack of snow (holiday storms rained away the snow at sea level).
Skookum Drainage
Closed
Closed Jan 5th due to lack of snow (holiday storms rained away the snow at sea level).
Turnagain Pass
Open
Opened Dec 13th.
Twentymile
Closed
Closed Jan 5th due to lack of snow (holiday storms rained away the snow at sea level).
Seward District
Carter Lake
Open
Opened Dec 13th.
Lost Lake Trail
Open
Opened Dec 13th.
Primrose Trail
Open
Opened Dec 13th.
Resurrection Pass Trail
Closed
Closed to motorized use for the 2022/23 winter season per Forest Plan. Open next season.
Snug Harbor
Open
Opened Dec 13th.
South Fork Snow River Corridor
Open
Opened Dec 13th.
Summit Lake
Open
Opened Dec 13th.

Subscribe to Turnagain Pass
Avalanche Forecast by Email

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.