CNFAIC Avalanche Advisory (Turnagain Pass Area)

Tuesday, May 1st 2012 Current Advisory (Turnagain Area)

Wendy Wagner — 2012-05-02T17:44:00+01:00

Danger Rating: NO RATING
Trend: NO TREND Danger

We are no longer issuing daily avalanche advisories for the GREAT SNOW YEAR OF 2011/12; However, this does not mean that the avalanche season has ended.

ANNOUNCEMENTS

Winter motorized recreation: Turnagain Pass remains open. Keep checking the list at the bottom of this page for updated open/closures through May.

We would like send out a HUGE THANK YOU to all of who have submitted observations this year, they are invaluable to us, and help us steer this operation in the right direction.
Winners of the "Observers of the Month" awards:
December - Bob Sutherland
January - Obadiah Jenkins
February - Mat Brunton
March - Bill Romberg
April - Kent May

We would also like to thank the Friends of the CNFAIC. We would NOT be here without your support and hard work - THANK YOU! This amazing and selfless group has a tireless passion for keeping people safe in the backcountry.

Finally, for sharing the valuable avalanche information that helps to greatly improves our forecasts, we would like to thank:
-Alaska DOT
-Alyeska Ski Patrol
-Chugach Powder Guides
-Alaska Railroad
-Alaska Avalanche School
-Alaska Pacific University
-Everyone else who has contributed this season

BOTTOM LINE
Is this a year for the record books? Overall good snow stability, great riding and skiing conditions, nice snow all the way to sea level and the list goes on, yes, a great season to be in Alaska. The largest and most exciting avalanches we have seen this year have occurred this spring (peruse the observation page for a look). With a lot of snow remaining on the ground, the avalanche potential will continue to be a very real concern. See below for more details.

SPRINGTIME AVALANCHE TIPS - Timing is everything

- Avoid the "shed cycle". Though many east (as can be seen on Seattle Ridge) and south slopes have undergone this phase of dangerous avalanche activity, there are still areas ripe to slide. Additionally, west and north aspects are still hanging in the balance. Keep an eye on the ridgetop weather stations for multiple days of above freezing overnight temperatures. This can signal a pack with limited refreezing and when followed by warm days (either sunny or rainy) can dramatically increase the likelihood of natural and human triggered avalanches. Careful route planning to say out from under slopes with wet and rotten snow is essential during this period.

- Once the snow has undergone the transition to a summertime pack and is freezing at night and warming during the day (the corn season), hitting the slopes early and getting off them when they become too sloppy is critical..

- Mushy snow more than 6" deep is a sign that it's time to exit the area. Following the aspects as the sun heats up the slopes over the course of the day, east to south then west, can make for great riding/skiing days ending in sunny tailgateing.

- Keep in mind, cloud cover 'holds in the heat' and can dramatically limit overnight refreezing. A shallow to no refreeze will not only give daytime heating a jump start on weakening the pack, but can produce less than stellar riding conditions.

- Beware for warm storms where rain is falling on snow. Especially when rain is falling on cold dry snow. This can quickly increase the avalanche danger.

- After a new snowfall, watch for the first rays of sun to trigger both slab and loose snow avalanches in the new snow. Often, these initiate just below trees and rocks.

- One of the easiest ways to stay safe in the springtime is knowing what kind of surface you are traveling on and under. Hard frozen snow, that easily supports a person and/or snowmachine, is unlikely to avalanche. Soft and saturated snow, deep enough to leave tracks you would not want to ski through when frozen, is a RED FLAG that the snow is losing its strength and becoming ripe to avalanche.

- Last, don't forget to plan your route back to the car. Does it take you under slopes that were frozen and safe earlier in the day, but now have been cooking in the sun waiting to slide on your return?

SEASON WEATHER ROUNDUP
Check out our new Weather History page where you can find our monthly weather charts. Here is the weather chart for April.

SNOW DEPTH -
Seasonal snowfall was 385" at Turnagain Pass SNOTEL (1880' on Center Ridge) - a GOOD year.

AIR TEMPERATURE -
Check out the cold temperatures we had this year - burr... Plus, the rapid springtime warm-up.
Sunburst weather station:

WIND -
Sunburst's wind sensor blew apart twice this season due to over 100mph winds (a record season with several storms gusting over 100mph). In fact, Sunburst hit its all time gust - 126mph.

Current weather can be found on the CNFAIC weather page!

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

Saturday, April 28th 2012 Current Advisory (Turnagain Area)

Wendy Wagner — 2012-04-28T17:04:00+01:00

Danger Rating: Moderate
Trend: NO TREND Danger

Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Saturday, April 28th 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).

ANNOUNCEMENTS
This will be our final advisory for the 2011/2012 winter season - has 6 months of AMAZING riding/skiing already past?! Look for an end of season update, recap and thanks on Tuesday May 1st.

BOTTOM LINE
There is a MODERATE avalanche danger today for wet slab, glide and wet loose avalanches on all aspects below 3500'. Cooler temperatures and wind should keep these concerns mostly at bay until the temperatures increase again (possibly Sunday afternoon or Monday when the danger may rise to CONSIDERABLE). Keep a close eye on westerly aspects as these have not undergone the "shed cycle" yet. In the case we accumulate more than a couple inches of snow today above treeline, there will be a MODERATE danger for storm snow instabilities. These include, wind slabs from 30-40mph east winds, soft slabs and new snow sluffs.

AVALANCHE DISCUSSION
Little avalanche activity has been seen/reported in the past several days as our clear skies have produced a predictable freeze/thaw regime which has tightened up the pack. The majority of the action (which included several different types of avalanches: wet loose, wet slab, dry slab and glide avalanches, whose remnants still litter the landscape) was from 4/12-4/22 when the pack received its first springtime shock. As Graham mentioned yesterday, you can't miss the Seattle Ridge carnage on a drive through Turnagain Pass.

Primary Concern - Wet Avalanches and Glide Avalanches
Medium to large wet slab and glide avalanches remain our primary concern. Although many east and south aspects have gone through their shed cycle during the past 2 weeks, westerly aspects have not and are still in large part intact and concerning. A look at the west face of Magnum yesterday showed several feet of wet sloppy snow under a 4-5" thick crust. This crust has been tying the slopes together but once it softens and looses its cohesion, through sun/rain/cloud cover, the sloppy snow underneath will be prime to slide. Cracks became noticeably more visible yesterday with our very warm temperatures and can be seen in the photo below of the west face of the Magnum ridge.

New snow concerns
With new snow on tap today and Sunday, the usual storm snow suspects (sluffs, soft slabs and wind slabs) will be a concern if we get more than a few inches. This should bond rapidly with our warm temperatures. However, this is the time of year the sun itself can act like a storm and be a powerful trigger, especially with new snow. Watch for wet point release and shallow slab avalanches at the first hint of sun after this system works though (likely on Sunday afternoon or Monday).

Cornices
Several of these large overhanging snow monsters are still sticking to the ridgelines despite the warm weather. They absolutely deserve an extra wide berth when traveling on ridges as they slowly peel/melt away.

Persistent Slab - Above treeline, Northerly aspects
Areas with dry snow still harbor at least one layer of buried surface hoar. The most reactive was buried on March 27th and is around 1-2' deep. We have not heard of an avalanche failing in this layer since April 17th but, it is good keep in mind it is out there.

MOUNTAIN WEATHER
Another sunny, gorgeous day greeted those that ventured into the hills yesterday. Light east winds, 40-50 degree temperatures and only a few clouds in the afternoon provided very comfortable traveling.

We have a weak storm system rolling through today into Sunday. Winds have increased to 20-25mph from the east on the peaks, clouds have moved in and temperatures have dropped to the upper 20's on the ridges and mid 30's around 1000ft. Light rain/snow should begin this morning but only an inch or two is expected to accumulate above treeline. The rain/snow line looks to be around 1400ft. Winds will increase into the 30-40mph range today and remain through tonight.

Another inch or two could fall overnight through Sunday for a combined 3-6" at the higher elevations by Monday. Easterly winds should subside tomorrow and temperatures stay relatively cool until Monday. Remember to check our weather page, link below, for the latest weather info.

CNFAIC Weather Page and the NWS forecast

This concludes our final advisory of the season. However, look for general information to be posted on Tuesday May 1st. Even though the season is finished, we still want your backcountry observations! They can be submitted by using the button at the top of this page or give us a call at 754-2369. Thanks and have a great summer!

Wednesday, April 25th 2012 Current Advisory (Turnagain Area)

Graham Predeger — 2012-04-25T17:05:00+01:00

Danger Rating: Moderate
Trend: NO TREND Danger

Good morning. This is Graham Predeger with the Chugach National Forest Avalanche Information Center on Wednesday, April 25th 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).

ANNOUNCEMENTS
The next advisory will be issued Saturday morning. Keep checking the photos/observations page for up to date information.

A big THANK YOU to everyone who showed up or stopped by Turnagain Pass last Sunday for the First Annual Corn Harvest Event, sponsored by the Friends of the CNFAIC!

BOTTOM LINE
A MODERATE avalanche danger exists this morning within the core advisory area where wet loose and wet slab avalanches are the primary concern as slopes as high as 3500' did not freeze overnight, or may have froze superficially. Later in the day, slopes at all elevations will continue to heat up and the danger may rise to CONSIDERABLE with natural avalanche activity moving up the spectrum from unlikely to possible. Avoid steep, rotten slopes where the snow cannot support your weight. Furthermore, limit time spent under glide cracks and cornices that have yet to release as these are ticking time bombs.

AVALANCHE DISCUSSION
A drive through Turnagain pass and one is able to see the extent of avalanche activity over the past week. Naturally occurring wet loose, wet slab, glide avalanches, glide cracks and even a couple dry slab avalanches have been observed since last Wednesday. Most of this activity is from 4-7 days ago and activity has slowed substantially since late last week as our snowpack continues its transition toward summer. However, new glide cracks are continuing to open up on south and east facing slopes in the Girdwood Valley and Turnagain pass areas.

Primary Concern - Wet Avalanches and Glide Avalanches
Wet avalanches will become more of a concern later in the afternoon/ evening as the sun breaks down bonds between individual snow grains. Before this happens, there is decent corn snow to be found, though timing is everything. Once a slope cannot support your weight (off your skis or snowmachine) and you are sinking past your boot tops, retreat. This is a good indicator that a slope is becoming dangerously unstable due to rapid warming.
Glide avalanches continue to pose a threat at all times during the day. Unpredictable by nature as to when a glide crack may release, the good news is that we know where they will release. If you see a glide crack (and there are many) limit your time spent underneath these. Do not high-mark under glide cracks, do not set your skin track under glide cracks, do not eat your lunch under glide cracks and you will not be in danger of getting hit by one of these ticking time bombs.

Cornices
As with glide cracks, avoid time spent below these behemoths, giving cornices an extra wide berth when travelling on ridges where cornices have built up over the season. These are particularly large this late in the season and prove to be very touchy as we progress into spring.

Persistent Slabs - Above tree line
There is an older layer of buried surface hoar from March that is still proving reactive in isolated areas above tree line. I observed a fresh slab that released in the last couple days just lookers right of the Squirrel Flats up-track. Buried surface hoar was likely the culprit in this wide, low angle avalanche. Though few and far between now, be aware that buried weak layers do still exist on higher elevation slopes with a northerly tilt.

MOUNTAIN WEATHER
The Jetstream continues to flow far south of mainland Alaska keeping any exciting weather at bay for the next few days. The big melt continues this week with daytime temperatures reaching into the 50's at 1000 feet and light winds from the northeast in the 3-17mph realm. Overnight, sea level temps dipped to 25 degrees in the eastern Turnagain arm area, though many mountain top areas struggled to break below the 32 degree mark (freezing).

Mostly clear skies will dominate our region over the next several days with a slight chance of isolated rain or snow as we head into the weekend.

CNFAIC Weather Page and the NWS forecast

Wendy will issue the next advisory Saturday morning. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.

Saturday, April 21st 2012 Current Advisory (Turnagain Area)

Wendy Wagner — 2012-04-21T18:09:00+01:00

Danger Rating: Moderate
Trend: NO TREND Danger

Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Saturday, April 21th 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).

ANNOUNCEMENTS
The next advisory will be issued Wednesday morning. Keep checking the photos/observations page for up to date information.

Don't forget to swing by the Turnagain Pass motorized lot tomorrow, April 22nd between 4 and 7pm for FREE FOOD and FUN at the 2012 Corn Harvest!!

BOTTOM LINE
We have a MODERATE danger this morning for wet loose and wet slab avalanches. A CONSIDERABLE danger exists on east facing slopes such as Seattle Ridge where avalanches have been seen daily - this is not the place to recreate under or on right now. All aspects and elevations may rise to CONSIDERABLE if the sun pokes through today. Sunday-Tuesday, we look to be in a freeze/thaw cycle with a generally LOW to MODERATE danger in the morning that quickly rises to CONSIDERABLE for wet avalanches later in the day. Steering clear of slopes with saturated snow to your boot tops, rotten snow that does not hold your weight, or areas under glide cracks is advised.

AVALANCHE DISCUSSION
It has been quite an eventful week for avalanche activity as the springtime shedding of the pack took effect after a warm storm was followed by sunny warm days. Wednesday, April 18th, seemed to be the height of activity to date, with several natural class 3 wet slab avalanches from Girdwood Valley through Turnagain Pass to Summit Lake. Alaska DOT crews shot down a very impressive large wet slab at Mile 44 that buried the (closed) road. Yesterday, we know of two naturals that released, the one pictured below on east facing Seattle Ridge and another large slide on the east face of Raggedtop in the Girdwood Valley.

The photo below is of a glide avalanche that released yesterday above the Turnagain Pass motorized lot (East facing around 2800').

Primary Concern - Wet Avalanches / Glide Avalanches
Now that much of the pack has been shocked by warm temperatures and sun, wet activity has become less widespread. Today, east winds and limited sun may reduce the heating of the pack but cloud cover may have limited the amount of refreezing overnight allowing for instability to increase rapidly during the day. We have been in a freeze/thaw cycle for the past few days and after our mixed weather today, we should return to this regime. The snowpack is on its way to developing drainage channels and forming a thick supportable crust, yet there are still areas that are sitting on the brink adjusting. Good pseudo-corn conditions have been found of late and hopefully that will continue into next week. Timing is everything this time of year and it is a good idea to get off of slopes that become soft up to your boot tops or become punchy.

Cornices
Cornices deserve a wide berth as they continue to be tender with our warm conditions.

Above treeline - Persistent Slab
An old layer of buried surface hoar sits 12-24" deep on west through northeast slopes at and above ~2500ft. This layer is suspected to be the weakness in several natural avalanches on 4/16-4/18: north facing Tincan mid-slope ~2500', west facing slope ~2500' up Center Creek and other slopes in the Kenai mtns.

MOUNTAIN WEATHER
Brilliant sunny skies, light winds and warm temperatures have made the dark days of winter a distant memory. We have been seeing temperatures in the 40's below treeline and upper 30's on the peaks. East winds have been 5-10mph.

Today, a shift is the weather is in store as a weak system in the Gulf will bring clouds and a chance for light rain below 1500' and a flurry or two above 1500'. No accumulation is expected (possibly a trace to an inch at the upper elevations). Easterly winds have bumped up to 10-20mph on the rigetops, where they should remain through Sunday. Temperatures should be in the 40's below treeline and 30's above. Sunday afternoon through Monday skies look to clear up with mild weather returning.

CNFAIC Weather Page and the NWS forecast

We will issue the next advisory Wednesday morning. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.

Wednesday, April 18th 2012 Current Advisory (Turnagain Area)

Wendy Wagner — 2012-04-18T18:38:00+01:00

Danger Rating: Considerable
Trend: Increasing Danger

Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Wednesday, April 18th 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).

ANNOUNCEMENTS
This advisory will be updated on Saturday morning. Keep checking our photos/observations page for more up to date information.

Alaska DOT crews may be conducting avalanche hazard reduction along the Seward Highway Wednesday-Friday. Visit 511.alaska.gov for updated information on road closures.

Remember to swing by the Turnagain Pass motorized lot on April 22nd between 4 and 7pm for FREE FOOD and FUN at the 2012 Corn Harvest!!

BOTTOM LINE
We have a CONSIDERABLE danger today (Wednesday) for wet loose and wet slab avalanches at all aspects and all elevations. With intense sun and light winds, possibly beginning later today and forecast through Friday, the danger may rise to HIGH - this can happen in a matter of hours. The mountains are warming up and the snow is shedding off in a variety of ways. VERY CAUTIONS travel is necessary in the backcounty and AVOIDING ALL AVALANCHE TERRAIN, THIS INCLUDES RUN OUT ZONES, IS ADVISED.

AVALANCHE DISCUSSION
The "shed cycle" is on as the mountain snowpack continues to warm, lose cohesion and, literally, fall down. It's that time of year where it's best to just let the pack do its thing for a week or two while it seasons into a summertime snowpack. Avalanche conditions are dangerous and riding conditions are , well, a sloppy mess.

Several wet loose and wet slab avalanches have been seen in the Eastern Turnagain Arm area during the past few days of rain and snow. The smaller slides are failing at and above treeline in the 2-10" of very wet snow from 4/15 and 4/16 and larger, up to class 3, slides in the older saturated snow below. The west face of Pyramid Pk. has a few brown streaks indicating glide/wet slab activity has increased on west slopes. South and east continue to produce avalanches and north, though more behind the game, is seeing shallow wet sluffs. North aspects, above treeline, also have the old March 27th buried surface hoar that may still be a player. This photo shows two crowns that look to be dry slab avalanches breaking on buried surface hoar and triggered by an overrunning wet sluff.

The photo below is of Seattle Ridge where slides have been occurring and more are possible.

Primary Concern - Wet Avalanches
Rain below 1500' and wet snow above for the past 3 days has added ~2" of water (slightly more in the Girdwood Valley) to our already warming pack. With sun in the forecast for Wed-Fri, including light winds and warm ambient temperatures, the pack will continue its demise. We have seen size 2 and 3 wet slides but these could become larger and running further in the next week. Staying away from any type of avalanche terrain is recommended until the pack adjusts, develops drainage channels and becomes a solid summertime pack.

Above treeline - Persistent Slab
There is a layer of buried surface hoar that sits 12-24" deep on northwest through northeast slopes at and above ~2500ft. This layer still may be reactive and is suspected to be the weakness in 2 natural avalanches on 4/16 on north facing Tincan mid-slope around 2500'.

MOUNTAIN WEATHER
Rain and snow has been over our area for the past 3 days and put down ~2" of water equivalent in the Turnagain Pass area. Rain fell below 1500', around 2" of extremely wet snow fell around treeline and upwards of 10" of heavy snow fell above 3000'.

Skies are clearing this morning and partly sunny conditions should prevail for the next few days. Temperatures look to be near 50F below treeline and in the 40's above. It's warm! Winds are expected to be light, 5-10mph from the east.

CNFAIC Weather Page and the NWS forecast

We will issue the next advisory Saturday morning. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.