Thursday, January 16, 2014

Bulletin Zone: 
All Zones
Bulletin Issued: 
Thu, 2014-01-16 06:54
Reporter: 
Keith Stebbings
Special Update: 

BCA is releasing a brand new beacon this month: The Tracker 3. As you know BCA is a long time supporter of WAC and sponsors us at the high level. This new beacon is lighter and smaller than the Tracker 2 and includes their advanced electronics and industry leading features that BCA has always been known for. Check out their many safety product offerings.

We want to thank our donors this week who have responded to our new donor popup and who realize our volunteer efforts require $ to support our educational, website and corporate expenses. They are: Aric, Dennis, Dan (NJ), Dan (Hood River) and Charla. We thank all of you.

 

Highlights: 

This is Keith Stebbings with your avalanche bulletin for Thursday, January 16, 2014. An active storm cycle lasting from late last week through Monday brought 11 to 23 inches of snow to our regional backcountry terrain. New snow but manageable instabilities quickly settled out, however natural soft slab releases on the old/new snow interface were quite numerous and kept seasoned BC recreationists off high angle terrain. With poor test scores lower in the snowpack on a persistent weakness the main concern is releasing a large and high consequence avalanche.

Avalanche headliner:  A snowmobile party of 5 triggered a large avalanche in the Elkhorns Sunday. 3 caught, carried and partially buried. Details in Recent Activity section below.

Reports of huge grins smiley that the new snow was not only welcome to cover the thinner snowpack areas and lingering obstacles but the turning conditions improved dramatically regionally.

Photo 1: 

As they say, a picture is worth a thousand words. Remember WAC's weather station high atop Mt. Howard (8150') is responsible for this great data courtesy of JosephOregonWeather.com who kindly provides a path to the internet for us. The best part is having historical data shown in an easy read chart. Your donor dollars help to maintain this station as well as the one we own on top of Anthony Lakes Mountain Resort.

Snow and Avalanche Discussion: 

One to two feet of snow fell in a series of impulses starting Friday and ending Monday morning. Winds were generally quite gusty during this storm cycle but have behaved themselves mid week with speeds generally below snow transport levels. Mostly sunny skies prevailed by late Monday through today. It appears as though some of the snow falling on Saturday was high in water content and some rain may have fallen on the snowpack at lower elevations. One observer mentioned a bit of a rime crust Monday on open surface snow at 6100' in solar sheltered terrain.

Midweek warmth and sun has led to surface snow warming with the usual wet loose indicators of pinwheels and rollers when the new snow saw sun for the first time on Tuesday.

Photo 2: 

Photo by Victor McNeil (WAC Observer) last weekend from his Norway BC report. See other revealing avalanche photos and detailed info from our regular WAC Observer Brian Sather in his BC report. Kip Rand submitted his latest BC report Wednesday evening.

 

Recent Activity: 

Sunday afternoon January 12, five snowmobilers were enjoying some fresh powder riding in Rock Creek Canyon deep in the Elkhorns about 11 miles SE of Anthony Lakes Mountain Resort. One rider was climbing a NE aspect, mid elevation slope when he triggered an avalanche mid way up the slope. The fracture propagated upslope catching, carrying and partially burying 3 of the party. Members of the party performed a self rescue and all made it out of the backcountry safely. WAC appreciates the candor in informing others of the hazards of avalanches and the lessons learned. See: https://www.facebook.com/dustin.stephens.79

Instabilities within the newest snow from last weekend have settled out by now. The new/old snow interface of the last storm cycle remains of concern and slope cuts could provide useful info in conjunction with other means to determine slope safety. Slope cuts are never trusted to reliably reach the lower persistent snowpack weaknesses.

Activity reported this week were numerous D2 size slides. (Large enough to injure, bury or kill a person). These observed slides occurred at mid elevations BUT all around the compass. Could this be less wind direction dependent and more due to snow load? Think about it.

Problem #1: 

It's called persistent for a reason. The mid pack crust/facet sandwich or graupel layer is showing reactivity and appears to be the weak layer in the recent snowmobile incident. Careful evaluation of a similar aspect and elevation test slope may give you data for a decision yay or nay. However, I am never trustful that stable test results warrant a go decision when spatial variability is at play. Poor snowpack structure trumps stable test results any day.

With continued worry and poor test results in the lower persistent weakness, most outback BC rippers had a high level of respect for and avoidance of avalanche terrain knowing a possible step down could lead to a very large, unmanageable and high consequence avalanche.

Problem #2: 

A catch-all icon for isolated wind slab, wet loose, wet slab and cornice fall. Normal caution means look out for everything else. Never let your guard down. Strong winds last weekend have built cornices off ridgelines and summits, along with wind slabs. Mid week heating and strengthening solar input has created pinwheels and roller balls, the first indicators that a wet slab release may not be far behind.

The Juicy, Techie Stuff: 

I'll be supporting the ECX sled dog race in Joseph wearing the snow safety officer hat among others.

I will be continuing the Snow Tech blog this season with interesting topic narratives and exploration.

 

 

General announcements: 

The tenth annual Eagle Cap Extreme (ECX) sled dog race will be starting a week from today, January 23 at 1pm. You can tune into the race communications HERE. Many of WAC's Board of Directors are intimately involved as volunteers. This is an exciting event with a 200, 100 and 62 mile race course. As of today there are over 20 mushers signed up and the race course travels all over the Wallowa Mountains with one checkpoint at Salt Creek Summit and one at Ollokot campground. See: http://www.eaglecapextreme.com/

 

Wallowa Mountain Weather Briefing: 
 
Looks to be high and dry for about a week before any storm of significance arrives in our area.

 

 

We are working directly with the National Weather Service in Pendleton through special briefings to provide you with applicable local mountain weather information. You should always obtain a weather forecast from National Weather Service before undertaking any winter outdoor activities.

Links to current weather forecasts issued by the National Weather Service are available on the Local Weather tab or by selecting your area of interest on the map shown on our homepage