Avalanche forecast

Blues

Wallowa Avalanche Center
View on map

Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Triggering a 1-2' thick avalanche remains possible on some slopes. Avalanches are more likely on shady slopes facing E-N-W and could occur on both sheltered mid-elevation slopes and in wind-affected terrain. Recent winds have formed fresh, hard drifts that are likely to be small but could be easy to trigger. 

This forecast is sponsored by the fine folks who brew excellent beer at Terminal Gravity in Enterprise, OR.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    A weak layer of buried surface hoar has been observed in the snowpack, now under a couple of feet of snow.  This weak layer can produce large avalanches but doesn't always provide warning signs of its existence.  You may hear/feel whumping or collapsing in the snowpack, which is a sure bet that surface hoar is beneath you.  There is also a good chance that these weak layers will not be felt or observed.  In this case, you will only know the weak layer exists is if you dig into the snowpack and conduct snowpack tests like the compression test (CT) and extended column test (ECT). It is possible the Blues will get up to 8" of new snow today and 6" of snow tomorrow. This new snow will add weight and stress the persistent weak layer increasing the likelihood of triggering a slide.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    If you observe dune-like formations, feel punchy snow, or observe shooting cracks from your skis or sled then avoid slopes greater than 30 degrees, or with consequential terrain above or below you.  The storm today will bring up to 8" of new snow to the Blues. This snow will be easily transported by moderate westerly winds onto leeward terrain features near ridgeline. A human-triggered shallow wind slab avalanche could stress the persistent weak layer deeper in the snowpack. If that weak layer were to fail, then the avalanche could step down and consume more of the snowpack resulting in a large and destructive avalanche.

Avalanche Discussion

We are in a tricky spot related to avalanche hazard right now. Throughout the ranges of northeast Oregon we have several widespread layers of buried surface hoar. The most reactive layer of buried surface hoar is down 1.5 to 2 feet in the snowpack. It was buried on 1/18. Buried surface hoar is a notorious persistent weak layer and has the added hazard of propagating fractures over large distances. What is tricky about surface hoar is that it isn't consistent across the snowscape. It largely lurks on more shaded and protected slopes. The likely place to find buried surface hoar is on E-N mid-elevation slopes below the ridgeline. Another tricky thing about surface hoar is that it is hard to see in the snowpack when digging a pit. The best way to test the upper snowpack for the presence of surface hoar is to do snowpack tests like the compression test (CT) and extended column test (ECT). If you get clean planar fractures on a thin weak layer, then you've likely found the buried surface hoar.

This doesn't mean surface hoar may not exist in the alpine or on more sunny slopes. That is what makes it tricky too. We are in a period right now where careful terrain evaluation and selection is needed to avoid the possibility of triggering a large and destructive avalanche. It is possible to trigger the surface hoar layer in the upper snowpack and have the avalanche step down into weaker layers in the lower snowpack. There are other buried weak layers deeper in the snowpack. The new snow forecast through Saturday will also add weight and stress to the snowpack heightening the possibility of triggering this nasty beast.

An example of this is a snowmobile triggered avalanche in the southern Wallowas on Tuesday that was 3' deep, 50 yards wide, and ran over a 100 yards. This slide was big enough to bury, injure, or kill a rider. If you are going into terrain steeper than 30 degrees, then you need to carefully evaluate the slope for buried surface hoar. And, if you don't know, then don't go. Keep your slope angles below 30 degrees to be extra safe.

_____________________________________________________________________________________________________________________________________________________________________________________________________________________________

 

The 11 Annual Eastern Oregon Backcountry Festival is coming up.  Join us for our biggest fundraiser of the year February 3-5th. 

  • Friday, Feb 3rd: HQ in La Grande we are showing "Buried" the 1982 Alpine Meadows Avalanche.  Doors Open @ 5:30, Pie Auction 6:30, Movie starts at 7! Tickets are $5 at the door.
  • Saturday, Feb 4th: Kip Rand Memorial Race registerhere.  Winners will receive $100 cash or an Anthony Lakes season pass for 23/24.  Mens and womens division.   (You must show up 15 minutes before the race starts at the EOBF tent near the rental shop. )
  • Snow safety clinics 10 AM Avalanche Companion Rescue Clinic.  Register here.  
  • 1 PM Snowpack Observation Clinic.Register here.  Space is limited, reserve your spot.  (You must show up 15 minutes before the clinics start at the EOBF tent near the rental shop. ) 
  • Bag of Hammers 3 PM at the Star Bottle Saloon.  Live auction and raffle.  
  • On Sunday you can join the forecasters for a tour into Angel Basin.  Register Here.  

If you aren't able to make it out for the events you can support the WAC by purchasing raffle tickets or bidding on items in our online auctionhere.  The online auction and raffle will run from Jan 20th at Midnight to February 5th at 8PM.  

Regions covered