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Current Advisory (Summit Lake Area)

Saturday, March 6th 2010

Created: Mar 6th 6:29 am
Updated: Mar 6th 8:02 am

Good morning backcountry travelers this is Alex McLain with the Chugach National Forest Avalanche Information Center on Saturday March 6 at 7 am. This will serve as a general backcountry avalanche advisory issued for Summit Lake as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

**This advisory is a new addition to the CNFAIC program, and will only be updated on Fridays and Saturdays for the time being, and all advisories expire 24 hours after being posted. Expired advisories can be accessed by looking through the advisory archive on the right. Backcountry travelers can analyze the weather trend between the expired advisory date and the current date to make pertinent avalanche terrain decisions.**

Based on recent observations and data, natural avalanches are likely, and human triggered avalanches are very likely. These are very dangerous avalanche conditions, and travel in avalanche terrain is not recommended.


AVALANCHE DISCUSSION
Summit Lake has received 12"+ of new snow with winds yesterday 15-30mph ESE with wind gust of over 50mph. Yesterday Jason and I went up to Summit and found moderate to heavy snowfall with rates greater than 1" an hour and high winds causeing white out conditions. The mountains where completely obscured from view making observations difficult. Rapid rates of precipitation and windloading will make human triggered avalanche very likely and natural avalanches likely so avoid steep slopes above 30 degrees, wind loaded slopes, and all avalanche run out zones. Lets give this new snow time to bond with the layers below.

WEATHER ROUNDUP

Weekly Roundup
During the last week we have had several storms with 6" snowfalls and the last storm which dropped 10-12"+ snow. This new snow is sitting on an ice crust with some bonding happening earlier in the week. Winds have generally been E to SE 20-30mph gust to 54 during these storms.
Hindcast (Last 24 hours)

3440’ – Fresno Wx Station-
Current temp is 15 (1 degrees colder than yesturday), and winds have been 15-30mph with max gust of 54mph ESE.
1400’ – Summit Lake Wx Station-
Current temp is 23 degrees (7 degrees colder than yesterday), with 6 inches of new snow at the snow depth gage. (At 11 AM on Friday we were seeing snow amounts just north of this location of 6-8 inches)
Nowcast

Temperatures have cooled off and winds have become light out of the NE 11mph with gust 19mph. An additional 1-4" are forecasted today with light snow currently falling.

Forecast
Zone Forecast: Western Prince William Sound Mobile Weather Information

Last Update: 500 AM AKST SAT MAR 6 2010

Today...Snow showers. Snow accumulation 1 to 4 inches. Highs in the upper 20s to lower 30s. South to east wind 10 to 25 mph becoming variable 10 mph in the afternoon. Through portage valley and turnagain arm...southeast wind 25 to 40 mph becoming variable 15 mph by noon.

Tonight...Numerous snow showers north of moose pass in the evening...then mostly cloudy with scattered snow showers. Mostly cloudy elsewhere. Snow accumulation up to 2 inches. Lows 5 to 20 above. Light winds except west wind 20 to 35 mph near whittier and north 10 to 20 mph near seward.

Sunday...Mostly cloudy. Isolated snow showers in the morning... Then a chance of snow in the afternoon. Highs in the 20s. Variable wind 10 mph. Through portage valley and turnagain arm... Light winds becoming southeast 10 to 20 mph in the afternoon.

Sunday Night...Snow. Areas of blowing snow. Lows 15 to 25. East wind 10 to 15 mph. Through portage valley and turnagain arm...east wind 15 to 30 mph increasing to 35 to 50 mph after midnight.

Monday...Snow...possibly mixed with rain. Areas of blowing snow. Highs in the 30s. East wind 15 to 30 mph except east 40 to 55 mph through portage valley and turnagain arm.

Monday Night...Mostly cloudy with scattered snow showers. Lows in the 20s.

Tuesday...Snow likely. Highs 25 to 35.

Tuesday Night...Cloudy with a chance of snow showers. Lows in the teens.

Wednesday Through Friday...Cloudy with a chance of snow showers. Highs 25 to 35. Lows in the teens.


Always remember that safe backcountry travel requires training and experience. You control your own risk by choosing where, when, and how you travel.

Thanks for checking today’s avalanche advisory. The next one will be posted on Friday March 12th.

Weather and Riding Updates for CNF

(Updated: Mar 09, 2010 )
AREA
RIDING STATUS
WEATHER AND RIDING CONDITIONS
GLACIER DISTRICT
Girdwood
Open
State owned land is OPEN for snowmobiles and their generally allowed uses. Muni and USFS land in the upper valley is closed to snowmachining.
Johnson Pass
Open
as of 03-04-2010 three day snow total - 16"
Placer River
Closed
3/8/2010 12-16" new snow. Still some areas of open water on the river. We are waiting to see how this storm finishes for a possible opener. Stay tuned over the next couple days, but right now it remains closed.
Skookum Drainage
Closed
Turnagain Pass
Open
as of 03-04-2010 three day snow total - 24"
Twentymile
Closed
3/8/2010 14" new snow. Still some areas of open water on the river. We are waiting to see how this storm finishes for a possible opener. Stay tuned over the next couple days, but right now it remains closed.
SEWARD DISTRICT
Carter Lake
Open
12" of snow with a good base, Trail looked good.
Lost Lake Trail
Open
Lost Lake Trail open 3/6, 24 inch base at parking lot. 4 inches of snow covering icy section 1st half a mile.
Primrose Trail
Open
as of 03-04-2010 three day snow total - 10"
Resurrection Pass Trail
Open
6" of snow with a good base of ice
Snug Harbor
Open
3/6 Road not plowed, icy sections, 24" of snow at parking area.
South Fork Snow River Corridor
Open
12" new snow watch for open water crossings
Summit Lake
Open
3/6 47" of snow

General Snow Conditions for the Turnagain Area - Updated As Necessary

Date
Snow Condition Update
Monday, March 8th 2010Parking Lot Snow Stake Measurements:
Eddies Lot: 22" new
Motorized Lot: 22" new
Sunburst: 15" new
Johnson Pass North Trailhead: unable to access parking lot

Ingram Creek: 11" new mixed with some rain
Placer Main/Overflow: 12-16" new mixed with some rain
20 Mile: 14" new mixed with some rain
Saturday, March 6th 2010Parking Lot Snow Stake Measurements (48 hour):
Eddies Lot: 12" new snow
Motorized Lot: 17" new snow
Sunburst Lot: 7" new snow
Johnson Pass North: 8" new snow
Friday, March 5th 2010Three day snow fall totals as of 03-04-2010:
Eddies-20"
Turnagain Motorized lot - 24"
Sunburst - 18"
Johnson - 16"
Lost Lake TH - 10" Lost Lake Trail is improving but still needs more snow cover before it can handle lots of snowmachine use.
Divide - 16"
Primrose - 10"
Moose Pass area - 8"
Summit - 6"
Cooper Landing - 4"
Wednesday, March 3rd 2010Parking Lot Snow Stake Measurements:
Eddies Lot: 13"
Motorized Lot: 14"
Sunburst: 6"
Johnson Pass North Trailhead: 6"
Tuesday, March 2nd 2010Parking Lot Snow Stake Measurements:
Eddies Lot: 3"
Motorized Lot: 4"
Sunburst Lot: 2"
Johnson Pass North Trailhead: trace
Sunday, February 28th 2010Parking Lot Snow Stake Measurements (24 hour):
Eddies Lot: 11" new snow
Motorized Lot: 5" new snow
Sunburst Lot: 3" new snow
Johnson Pass North: 3" new snow
Friday, February 26th 20105-7" of new light density snow, limited wind, temps in teens to low 20's
- soft slabs present
Sunday, February 21st 2010In the last two weeks Turnagain Pass received 7.5 feet of snow and over 9 inches of water, with consistent rain below 1000 feet from Feb 10-19. Gale to storm force easterly winds pummeled us the last three days of the storm. The storm peaked on Feb. 18 along with the natural avalanche cycle. Many large natural avalanches occurred on all aspects and elevations.
Friday, February 19th 2010Rain line pushed to 3000 ft. 3-5 inches of water this week and 5 plus feet of snow above a fluctuating snowline.
Thursday, February 18th 201024 hour snow accumulations:
Johnson -1.5"
Sunburst - 1"
Motorized - 8"
Eddies - 8"
Monday, February 15th 201017 inches of new snow and 2 inches of water in the last 24 hours. Rain below 1000 feet and gale force easterly winds.
Saturday, February 13th 2010SNOWMACHINER FATALITY
-A snowmachiner triggered a large avalanche on the west ridge of Grandview at approximately mile 43 of the railroad tracks between Portage and Moose Pass. Two riders were caught and buried, one was killed, and one is still missing. The avalanche possibly failed on a surface hoar/crust combo.
-4 feet of new snow and 4 inches of water in the last 8 days
-Numerous medium to large natural avalanches on Friday Feb. 12 failed on buried surface hoar layers.
Friday, February 12th 2010Parking Lot Snow Stake Measurements (24 hour):
Eddies Lot: 6" new snow
Motorized Lot: 8" new snow
Sunburst Lot: 2" new snow
Johnson Pass North: trace of new snow
Wednesday, February 10th 2010Parking Lot Snow Stake Measurements (24 hour):
Eddies Lot: 3" new snow
Motorized Lot: 2.5" new snow
Sunburst Lot: .5" new snow
Johnson Pass North: trace of new snow
Tuesday, February 9th 2010Parking Lot Snow Stake Measurements (24 hour):
Eddies Lot: 3" new snow
Motorized Lot: 3" new snow
Sunburst Lot: 1" new snow
Johnson Pass North: 2" new snow
Monday, February 8th 2010Parking Lot Snow Stake Measurements taken at (24 hour):
Eddies Lot: 3" new snow
Motorized Lot: 2.5" new snow
Sunburst Lot: 1" new snow
Johnson Pass North: 1" new snow
Sunday, February 7th 2010**OUTSIDE ADVISORY AREA**
-Skier-triggered avalanche South Fork Eagle River at 3500 feet on a run locally known as "Leighow". Triggered near a shallower spot in the snowpack near a rock band, most likely recently wind loaded. It ran for 1800 feet down the chute.
Sunday, February 7th 2010Parking Lot Snow Stake Measurements (2/5 to 2/7):
Eddies Lot: 13" new snow
Motorized Lot: 10" new snow
Sunburst Lot: 8" new snow
Johnson Pass North: 6" new snow
Saturday, February 6th 2010SKIER-TRIGGERED AVALANCHE
-13 inches of new snow/1 inch water along with moderate to gale force easterly winds in the last 36 hours.
-A skier triggered an avalanche on a southwest aspect of Tincan at 3000 feet in an area called the Kitchen Wall. The skier was caught, carried, and partially buried but able to dig himself out. We estimated the slide at 150 feet wide, 200 feet long, 14 inches deep at the crown face, and 39 degrees at the trigger point. The slide failed below a recently formed windslab on a very small layer of buried surface hoar on top of a 1mm thick melt-freeeze crust.
-Numerous shooting cracks on steep rollovers breaking down about a foot deep. Recently formed windslabs (2-6 inches thick) were especially reactive, fracturing 25-60 feet wide on leeward slopes.
Tuesday, February 2nd 2010SNOWMACHINE-TRIGGERED AVALANCHE
Observed on Tuesday Feb 2. We are not sure exactly when it was triggered, but it looked recent. See photo gallery.
Friday, January 29th 2010Skier triggered avalanches on the west face of Superbowl Peak and the south side of Cornbiscuit. They measured 10 inches deep, 45-60 ft wide and ran 500 to 900 ft. Failure most likely occurred on the old snow, new snow interface where buried surface hoar is present up to 3500ft.
Wednesday, January 27th 2010Parking Lot Snow Stake Measurements:
Eddies Lot: 1" new snow
Motorized Lot: 1" new snow
Sunburst Lot: 1" new snow
Johnson Pass North: 1" new snow
Monday, January 25th 2010Sunny skies, light winds, and mountain temps in the 20's the last 5 days. Only a few isolated pockets of instability reported in addition to sluffing on 40+ degree terrain:
1/21: Small skier-triggered soft slab 1 ft. deep on Cornbiscuit
1/23: Skier-triggered soft slab on the west face of Magnum at 2500 feet. This slide was estimated at 30-50 feet wide, 1 ft. deep, and 150 feet long.
1/24: Loud whumph reported in the trees below 1500 feet north of Tincan.
Tuesday, January 19th 2010Parking Lot Snow Stake Measurements:
Eddies Lot: 2" new snow
Motorized Lot: 2" new snow
Sunburst Lot: 2" new snow
Johnson Pass North: 1" new snow
Sunday, January 17th 2010Parking Lot Snow Stake Totals (Last measurement was on Wednesday 1/13/10):
Eddies Lot: 18" new
Motorized Lot: 17" new
Sunburst: 8" new
Johnson Pass North: 6" new
Saturday, January 16th 2010Numerous soft slab avalanches running on the crust layer with whumphing at the lower elevations:
-Big soft slabs releasing on steep rollovers on Tincan.
-Ski cuts in the upper elevations of the Girdwood Valley produced 4-6 inch thick soft slabs propagating down the walls of a steep chute.
Thursday, January 14th 2010Skier Triggered avalanche on west aspect, 3800 ft, Pastoral Peak, Turnagain Pass. Steep chute with a 1.5 ft deep crown face, wall to wall, ran 900 feet, SS-AS-2-O . The bed surface was the crust layer.
Wednesday, January 13th 2010Parking Lot Snow Stake Measurements 1/13/2010
Eddies Lot:3.5 inches new snow
Motorized Lot:2.5 inches new snow
Sunburst Lot:2 inches new snow
Johnson Pass North Lot:1 inch new snow
Tuesday, January 12th 2010Parking Lot Snow Stake Measurements 1/12/2010
Eddies Lot:7 inches new snow
Motorized Lot:6 inches new snow
Sunburst Lot:5 inches new snow
Johnson Pass North Lot:3 inches new snow
Thursday, January 7th 2010Rain to 2800-3000 feet today with strong easterly winds. A few small point release wet slides observed.
Tuesday, January 5th 2010Glide Crack Avalanche Observed (see photo gallery)
We are not exactly sure when this glide crack failed, but it probably avalanched sometime on Monday Jan 4, 2010.
Monday, December 28th 2009Warm temps, strong easterly winds, and rain below 2000 feet December 21-27. Snowfall & water totals for Center Ridge Wx station 12/21-12/27: 25" snow, 3.5" SWE
Thursday, December 24th 2009MANY NATURAL AND HUMAN TRIGGERED AVALANCHE RECORDED
Most of the avalanche activity occurred on 24 hour old snow, 6-8 inches deep.
24 hours: 5-14 inches of snow fell in Girdwood, 10 inches in Turnagain Pass, and 4 inches in Summit Lake. Approximate 3 day storm totals for Girdwood 15-28 inches, Turnagain Pass 20 inches, and Summit Lake 9 inches. These amounts are above the snowline. The snowline has fluctuated from sea level to 1200 ft. Almost all precip has been rain from sea level to 800 feet.
Saturday, December 19th 2009SKIER TRIGGERED AVALANCHE
-A skier triggered a small avalanche between 2500 and 3000 feet elevation on Tincan on a slope below the main bowl. This slide was 1.5 feet deep, 20 feet wide, and ran 30 feet long.
-40 to 50 ft. long shooting cracks were reported at 3000 feet elevation on Manitoba. The wind was actively loading the slope at the time, and the cracks went down 2 feet to the new snow/old snow interface.
Thursday, December 17th 2009Snow stake totals:
Eddies Lot: 5" new
Motorized Lot: 4" new
Sunburst Lot: 3" new
Johnson Pass North Lot: 4" new
Wednesday, December 16th 2009Parking Lot Snow Measurements:
Eddies Lot: 4" new
Motorized Lot: 4" new
Sunburst Lot: 4" new
Johnson North Lot: 3" new
Tuesday, December 15th 2009Parking Lot Snow Measurements:
Eddies Lot: 3" new
Motorized Lot: 4" new
Sunburst Lot: 5"
Johnson Pass North: 4"
Sunday, December 13th 2009No new snow in the last 12 days. We had a strong inversion for 7 days from Dec 6-12 with fog down low and above freezing temps at the higher elevations. The warmest temps occurred Dec 7-9 with readings in the mid to upper 40's above 3000 feet elevation. Winds were light and variable during the inversion.
Thursday, December 3rd 2009NATURAL AVALANCHES
Medium sized Class 2 Natural Avalanches were observed on Tincan (see Photo Gallery). Large Class 3 natural avalanches observed on the south and west aspects of Sunburst and Magnum. Most of these failed on the facets on the ground during the height of the storm on Tuesday 12/1/2009.
Wednesday, December 2nd 2009Parking Lot Snow Measurements for Tuesday 12/1/09:
Tincan Lot: 24-28 inches of new wet snow
Motorized Lot: 22 inches of new snow
Sunburst Lot: 10 inches of new very wet snow
Johnson Pass Trailhead: 5 inches of new very wet snow
Sunday, November 29th 2009Parking lot storm snow totals since Monday 11/23/09
Eddies Lot: 27" new snow
Motorized Lot: 31" new snow
Sunburst Lot: 20" new snow
Johnson Pass Trailhead: 14" new snow
Saturday, November 28th 20092 feet of snow has fallen in the last 24 hours in many areas covered by this advisory. Most of that fell yesterday. 4 to 6 inches fell last night. 2 to 3 inches of water equivalent fell in this storm. Snowfall totals for the two day storm range from 1 to 2 feet at sea level and 3 to 4 feet above 500 ft.
Monday, November 23rd 2009Eddies Parking Lot: 12" new wet snow (rain/snow mix)
Motorized Parking Lot: 24" new snow
Sunburst Parking Lot: 16" new snow (rain/snow mix)
Johnson Pass Trailhead: 3" new snow

Natural avalanches and human/triggered avalanches observed in Girdwood Valley and Turnagain Pass.
Thursday, November 12th 2009Nov. 12, 2009 - 4-6 inches of new snow yesterday over the advisory area. Center Ridge station at 1000 ft in Turanagain Pass is reporting 19 inches total snowpack. Expect to see 9-10 inches at the highway elevation of 1000 ft in T. Pass. The first report of a snowboard triggered avalanche came in today. A rider lost his board yesterday at Flattop. No further details. Although outside our advisory area this reminds us that winter and avalanche season has arrived.
Tuesday, November 10th 2009Nov. 10, 2009 - 4-6 inches at 1000ft, 14-15 inches at tree line, 0-30 inches in the alpine due to wind erosion or deposition.
Monday, October 12th 2009Oct. 12, 2009 - Very warm start to October. Snow line back to 4000 ft. Most ridgetop snow has melted back in the advisory area. Valley temps in the 50's. An ENSO (El Nino Southern Oscillation ) pattern is forecasted for the 09-10 season. This is subject to debate but usually means warmer, drier temps for us in general. Although remember 1998-99 (~1000in).
Thursday, September 24th 2009Sept. 24, 2009 - First measurable snowfall at higher elevations. Snow continued through Oct. 25. Approx. 3-4 inches with up to a foot in the Upper Glacier Creek drainages. Snow line approx. 2000 ft.

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:
The Friends of the Chugach National Forest Avalanche Information Center
Thanks to our Sponsors:
and to our Members!

View an older advisory (Summit):

Mar 12th, 2010 -- Mar 14th, 2010
  Level 1 Backcountry Avalanche Hazard Evaluation and Rescue Course
Great intro to safe backcountry travel! Given by AK Avalanche School. Location: Turnagain Arm. 3 Full Days. Visit AlaskaAvalanche.com for details
Mar 17th, 2010
6:30 PM
  Decison Making in the Backcountry
The CNFAIC will talk at the Mountaineering Club of AK meeting on March 17th at the BP Energy Center. The meeting is open to the public and starts at 630 pm. Carl Skustad will present a talk on Decision Making in the Backcountry using Web based technology. Learn how avalanche forecasts are made and how you can make your own.
Mar 19th, 2010 -- Mar 22nd, 2010
  Level 2 Backcountry Avalanche Hazard Evaluation Course
Hone your avy knowledge! Given by AK Avalanche School. Location: Hatcher Pass & Turnagain Arm for 4 Full Days. Visit AlaskaAvalanche.com for details
Mar 23rd, 2010 -- Mar 28th, 2010
  7th Annual Jeff Nissman TelePalooza Festival
It's all happening at Alyeska Resort in Girdwood. Visit: telepalooza.com
Apr 2nd, 2010 -- Apr 4th, 2010
  Women’s Backcountry Travel Weekend - Valdez
Become an Avy Savvy gal! Women’s Backcountry Travel Weekend at Thompson Pass. Build competence and confidence to make good decisions in avalanche terrain. This introductory class focuses on planning and preparation, terrain selection and human factors. Avalanche rescue skills will be covered as well. All women – all fun. The instructor is Sarah Carter. visit www.alaskasnow.org for more info
Apr 9th, 2010 -- Apr 10th, 2010
  Alaska Avalanche School - Wet Snow Evaluation Workshop
Wet Snow Evaluation Workshop Location: APU & Turnagain Arm for 1.5 Days $135 visit alaskaavalanche.com for more info