Mon, March 09, 2015 Turnagain Pass Avalanche Forecast

Mon, March 9th, 2015

Alpine

Above 2,500'

2 - Moderate

Treeline

1,000'-2,500'

1 - Low

Below Treeline

Below 1,000'

0 - No Rating

1 - Low

2 - Moderate

3 - Considerable

4 - High

5 - Extreme


Travel Advice	Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.	Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.	Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.	Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.	Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
Likelihood of Avalanches	Natural and human-triggered avalanches unlikely.	Natural avalanches unlikely; human-triggered avalanches possible.	Natural avalanches possible; human-triggered avalanches likely.	Natural avalanches likely; human-triggered avalanches very likely.	Natural and human-triggered avalanches certain.
Avalanche Size and Distribution	Small avalanches in isolated areas or extreme terrain.	Small avalanches in specific areas; or large avalanches in isolated areas.	Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.	Large avalanches in many areas; or very large avalanches in specific areas.	Very large avalanches in many areas.

Avalanche Problem 1

Wind Slabs

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

More info at Avalanche.org

Winds yesterday out of the South and West loaded slopes that don’t typically get loaded. Yesterday my partner and I watched this loading as it happened. Some areas were sheltered enough by surrounding terrain which prevented this from occurring. What this means is that there are now 1-2 day old wind slabs up to a foot in depth on a variety of aspects. On Turnagain Pass steep upper elevation North and East facing terrain is suspect. In the Girdwood Valley one large natural avalanche released over the weekend as a result of recent winds on a Southeast aspect. Winds will continue generally out of the Northwest today in the 20 mph range, helping to slightly increase the size and sensitivity of slabs.

Cardinal directions aside, it is more important to be able to recognize wind loaded slopes before you are on them. Snow that looks pillowy, feels stiff or sounds hollow should be approached with caution in steep terrain. Shooting cracks and collapsing are sure signs that the snow is unstable. Probing with a ski pole, hand pits, and feeling with your skis or board will allow you to assess the snow below your feet. Avoidance of terrain over 35 degrees with recent wind loading will be important today.

West winds loading East aspects along Seattle Ridge March 8, 2015

wind loading Seattle ridge

Avalanche Problem 2

Dry Loose

Dry Loose

Dry Loose avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.

More info at Avalanche.org

Areas sheltered from the winds will be holding 3-8” of low density snow. On sustained slopes over 40 degrees, expect human triggered sluffing to occur. These sluffs should be low to medium volume and large enough to knock a person over. This problem becomes more pronounced when traveling above terrain traps such as gullies, cliff bands or trees.

Weather

Mon, March 9th, 2015

Clear, cold and windy sums up the weather over the past 24 hours. Cold air moved in behind the system that left new snow throughout the region. Winds yesterday were strong and blowing out of unusual directions (see video). Clouds moved in late in the day and left a skiff of new snow.

Today expect similar conditions. Ridgetop temperatures will be in the single digits F. Winds will be out of the Northwest at 15-20mph. Thin clouds and light flurries this morning will give way to clearing skies by the afternoon.

Clear skies and cool temps are on tap for the first half of the week as high pressure gradually sets up over Southcentral Alaska. Winds should diminish after today.

PRECIPITATION 24-hour data (6am – 6am)

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	17	0	0	44
Summit Lake (1400′)	17	0	0	9
Alyeska Mid (1700′)	19	0	0	28

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	7	WNW	9	41
Seattle Ridge (2400′)	12	W	19	53

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
10/27/24	Turnagain	Observation: Tincan	Michael Kerst
10/21/24	Turnagain	Observation: Turnagain Pass Road Observation	Trevor Clayton
10/19/24	Turnagain	Observation: Tincan – Below Todds Run	Andy Moderow
10/18/24	Turnagain	Observation: Taylor Pass	Eli Neuffer
10/15/24	Turnagain	Observation: Tincan Common	John Sykes Forecaster
10/14/24	Turnagain	Avalanche: Tincan	CNFAC Staff
05/13/24	Turnagain	Observation: Eddie’s, Sunburst, Seattle, Cornbiscuit, Pete’s South	H Thamm
05/13/24	Turnagain	Observation: Turnagain Pass non-motorized side	Amy Holman
05/12/24	Turnagain	Observation: Warm up Bowl	Tony Naciuk
05/07/24	Turnagain	Observation: Turnagain Pass Wet Slabs	A S

Riding Areas

The riding areas page has moved. Please click here & update your bookmarks.