Wed, November 29, 2017 Turnagain Pass Avalanche Forecast

Wed, November 29th, 2017

Alpine
Above 2,500'

Considerable (3)

Treeline
1,000'-2,500'

Considerable (3)

Below Treeline
Below 1,000'

Considerable (3)

Alpine Above 2,500'		Considerable (3)
Treeline 1,000'-2,500'		Considerable (3)
Below Treeline Below 1,000'		Considerable (3)

Danger Scale:

No Rating (0)

Low (1)

Moderate (2)

Considerable (3)

High (4)

Extreme (5)

Avalanche Problem 1

Storm Slabs

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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

New snow, rain and sustained winds overnight have elevated the avalanche danger. 8-10″ of snow fell at upper elevations in Girdwood and 5-8″ at Turnagain in the last 24 hrs. Winds were easterly 20-30 mph with gusts into the 50s. Unfortunately some of the precipitation has fallen as… yuck, rain to around 1500′, maybe a bit higher. It is 34F at the Center Ridge Snotel (1880′) this morning. Yesterday the balance had not quite been tipped by new snow and wind loading but there was widespread cracking, whumpfing and a recent small natural avalanche observed (red flags). Hand pits showed failure on isolation between new snow and the underlying facets. This weak snow rests either on the ground or overlying a melt-freeze crust near the ground. With the additional snow and wind loading overnight this now sits below a more cohesive slab. Triggering a slab on steep terrain will be likely, especially in leeward, wind loaded areas. This snowpack set-up has the potential to be very touchy. Collapses (whumpfs) may propagate failure over large pieces of terrain and remote triggering an avalanche is possible. Don’t let early season stoke lure you into a dangerous spot. Overall it is still fairly shallow and rocky, getting caught in an avalanche could take you for a very unpleasant ride. Rain falling on this snowpack will also add weight and break up bonds. Wet loose avalanches may run naturally at low elevations in steep channeled terrain.

Quick snowpit at 1000′ near large collapse. Weak facets below new snow.

Cracking in snowpack near skin track, propagating across terrain.

Weather

Wed, November 29th, 2017

Yesterday was mostly overcast with light precipitation on and off throughout the day. Turnagain saw a few breaks in the clouds. Winds were easterly 10-20 during the day, ramping up overnight into the 30s with gusts into the 50s. Overnight snow picked up and rain fell to around 1500′. 8-10″ of snow fell at upper elevations in Girdwood with .6-1″ of SWE (snow water equivalent). Turnagain picked up 5-8″ at .5 SWE. Temperatures were in the mid 30Fs to mid 20Fs depending on elevation.

Today will be mostly cloudy with snow showers. These showers may be locally heavier at times due to unstable air behind the current front. An additional 1-5″ of snow is forecasted to fall. Winds will be easterly 10-20 mph with gusts into the 30s. Rain/snowline is expected to drop as temperatures cool down in the afternoon/evening. Temperatures will be in the mid 30Fs to mid 20Fs. Light snow showers may continue overnight.

Thursday will be mostly to partly cloudy and cooler with a wind shift to the NW. Temperatures will be in the 20Fs dipping into the teens at night. There is a break in the stormy pattern on Friday before more unsettled weather moves in again over the weekend.

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	34	6	.5	12
Summit Lake (1400′)	32	0	0	7
Alyeska Mid (1700′)	32	8	.6	14

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	23	ENE	28	56
Seattle Ridge (2400′)	26	rimed	rimed	rimed

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
01/27/22	Turnagain	Observation: Tincan Trees/CFR	Schauer/ Rothman Forecaster
01/25/22	Turnagain	Avalanche: Seattle Ridge	Wagner / Keeler Forecaster
01/24/22	Turnagain	Avalanche: Tincan	Wagner / AJB Forecaster
01/23/22	Turnagain	Observation: Pete’s North	Sykes / Sullivan / Stiegel Forecaster
01/21/22	Turnagain	Observation: Tincan	Sykes / Mehl
01/20/22	Turnagain	Avalanche: Tincan Proper	Anonymous
01/20/22	Turnagain	Observation: Super Bowl	Schauer/ Rothman Forecaster
01/20/22	Turnagain	Avalanche: Tincan	Kit Barton
01/20/22	Turnagain	Avalanche: Eddies	Andy Moderow
01/19/22	Turnagain	Observation: Lynx Creek	Sykes / Schauer Forecaster

Riding Areas

Updated Wed, December 01st, 2021

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	Open as of Dec 1st.
Placer River	Open	Open as of Dec 1st. Limited parking due to Portage curve construction.
Skookum Drainage	Open	Open as of Dec 1st. Limited parking due to Portage curve construction.
Turnagain Pass	Open	Open as of Saturday, Nov 27. Be aware of early season hazards (alders/creeks) and open water.
Twentymile	Open	Open as of Dec 1st.
Seward District
Carter Lake	Open	Open as of Dec 1st.
Lost Lake Trail	Open	Open as of Dec 1st.
Primrose Trail	Open	Open as of Dec 1st.
Resurrection Pass Trail	Open	Open as of Dec 1st.
Snug Harbor	Open	Open as of Dec 1st.
South Fork Snow River Corridor	Open	Open as of Dec 1st.
Summit Lake	Open	Open as of Dec 1st.