THIS AVALANCHE ADVISORY EXPIRED ON December 9, 2017 @ 6:51 am
Avalanche Advisory published on December 8, 2017 @ 6:51 am
Issued by Melissa Hendrickson - Idaho Panhandle Avalanche Center

St. Regis Basin/Silver Valley

bottom line

Rain and warm temperatures over Thanksgiving had a toll on the depth of our snowpack. The newer snow is fairly well bonded to the Thanksgiving crust, but small windloaded pockets were observed on all aspects.  Surface hoar and near surface faceting was also observed.  Looking ahead at the weather forecast, no new precipitation is expected for a while and daytime highs over the weekend could form sun crusts.

How to read the advisory

St. Regis Basin/Silver Valley

How to read the advisory

Rain and warm temperatures over Thanksgiving had a toll on the depth of our snowpack. The newer snow is fairly well bonded to the Thanksgiving crust, but small windloaded pockets were observed on all aspects.  Surface hoar and near surface faceting was also observed.  Looking ahead at the weather forecast, no new precipitation is expected for a while and daytime highs over the weekend could form sun crusts.

1. Low

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Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

?

Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

?

Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Wind Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Recent storms have bonded well to the Thanksgiving Crust, but look for small pockets of windloading on lee aspects.  Small windloaded pockets as well as surface hoar formation were observed on all aspects, and near surface faceting was observed on northern aspects.  Pack depths at elevation are in the 20 to 30cm range on the south facing aspects and 40 to 60 cm on the north facing aspects.

Weather and CURRENT CONDITIONS
weather summary

In mountain areas, today will be sunny with a high near 40 and south wind around 7 mph. Tonight is mostly clear with low around 26 and southwest winds 5 to 7 mph. Saturday is sunny with highs of 44 and partly cloudy at night with a low of 29. Southwest wind around 6mph.  Sunday mostly sunny with highs of 44 and overnight partly cloudy and lows around 30.  

Weather observations from the Region
0600 temperature: 31 deg. F.
Max. temperature in the last 24 hours: 31 deg. F.
Average wind direction during the last 24 hours: NW
Average wind speed during the last 24 hours: 5 mph
Maximum wind gust in the last 24 hours: 6 mph
New snowfall in the last 24 hours: 0.1 inches
Total snow depth: 15 inches
Disclaimer

Avalanche conditions change for better or worse continually. Backcountry travelers should be prepared to assess current conditions for themselves, plan their routes of travel accordingly, and never travel alone. Backcountry travelers can reduce their exposure to avalanche hazards by utilizing timbered trails and ridge routes and by avoiding open and exposed terrain with slope angles of 30 degrees or more. Backcountry travelers should carry the necessary avalanche rescue equipment such as a shovel, avalanche probe or probe ski poles, a rescue beacon and a well-equipped first aid kit.  For a recorded version of the Avalanche Advisory call (208)765-7323.