Avalanche Advisory published on March 15, 2017 @ 6:21 am
Issued by George Halcom - Payette Avalanche Center
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The avalanche danger is MODERATE at all elevations and all aspects due to human triggered avalanches being possible. A sustained lack of freezing temperatures over the last 48 hours, with rain on snow today, will make loose wet avalanches our primary concern. Today as the snow pack continues to transition from 'damp' to 'wet', the danger could rise to CONSIDERABLE due to the decreasing strength of the snow pack and the increase in the possibility of natural wet slab avalanches.

How to read the advisory

  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Very Likely
  • Size ?
    Very Large

It is going to be warm and wet at all elevations and all aspects of the PAC advisory area today. The PAC Granite Mountain weather station had a low temperature of  37 degrees last night, while at Secesh Summit SNOTEL the low temperature overnight only got down to 40 degrees. As the day progresses, and more rain falls on snow, expect to be able to 'push' loose wet snow down any steep slopes. While these trains of goo move slower that a dry slab avalanche, if triggered on a steep slope they could take you somewhere you don't want to go. So use caution today riding near road cuts, creeks, gullies, and any other terrain features that look like it could ruin your day if you were to get pushed into it by a tree snapping wet snow avalanche.

So what does this all this warming mean for the snow pack..? Well, if we were to have more than a couple of nights without below freezing temperatures, the snow pack would become isothermal and the chances of large wet snow avalanches would increase dramatically. This is due to the decrease in strength of the snow pack from water peculating down through the entire pack and the bonds between the layers and grains of snow weakening. Simply put, the snow pack becomes one big, sloppy, melting snow cone. 

What makes it better....? Cold temperatures for a long enough time that the snow pack is able to refreeze, and in turn regain it's strength. Let's hope the current forecast for a slight cool down tonight comes to fruition. 

Avalanche Problem 2: Cornice
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Very Likely
  • Size ?
    Very Large

Give ridge lines with cornices a bunch of respect and stay far back from what you might think is the edge of the world, and the start of the cornice. These monsters are hanging out fighting gravity as I am writing this. Use vegetation lines or rock as clues to be sure you are not standing out on a 'trap door' that is a cornice. 

advisory discussion

Snowmobiler/Snowbiker Travel Restrictions: Please respect these closures and other users recreating in them.  Winter Travel Map(East side). You can download the map to the AVENZA app on your phone, and know your exact location while you are out riding.  It is your responsiblity to know where closures exist on the forest.

The Granite Mountain Area Closure is in effect Jan15-March 31, please respect Snowcats operating, signed and unsigned closures and other users in this and nearby areas.  In addition there are other areas on the Payette National Forest that are CLOSED to snowmobile traffic including Jughandle Mt east of Jug Meadows, North of Boulder Mtn, East of Rapid Peak, North of the 20 mile drainage, Lick Creek/Lake Fork Drainage (on the right side of the road as you are traveling up canyon), and the area north of Brundage Mt Ski area to junction "V" and along the east side of Brundage and Sergeants' Mts. with the exception of the Lookout Rd( junction "S").

Photo 1 is from the edge of the signed Brundage Mt. Ski Area just past the Ski Area parking lot, photo 2 is of sled tracks ignoring Catski terrain signs...there is alot of snow out there folks.  Don't be "that" guy on a sled that gives sledders a bad reputation... please respect closures and other users.

The Friends of the Payette Avalanche Center (FPAC) needs YOU! We are in desperate need of more user support and financial assistance. The avalanche forecast is not a guaranteed service, and is in jeopardy of dwindling down to only a couple of days a week in the near future.We have equipment that is overdue for replacement but lack the funds to purchase new gear including weather station parts and our forecast sleds.  Please help if you can by clicking the DONATE tab above. If you value this life saving information, make a donation or help the FPAC in raising funds for the future.

recent observations

No new human or natural triggered avalanches have been reported. 

A list of OBSERVATIONS can be found here.

CURRENT CONDITIONS Today's Weather Observations From the Granite Weather Station at 7700 ft.:
0600 temperature: 37 deg. F.
Max. temperature in the last 24 hours: 41 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 12 mph
Maximum wind gust in the last 24 hours: 25 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: NA inches

Today, expect  scattered rain showers before noon, then rain and snow showers. High near 39. Breezy, with a southwest wind 14 to 21 mph. Chance of precipitation is 80%. Total daytime snow accumulation of less than a half inch possible.

Showers in northern-most zones today on the periphery
of warm upper ridge. Dry elsewhere. A little cooler today except
in south-central Idaho with warm with upper ridge still there. Ridge
will be shifting eastward this afternoon allowing the northern
showers to spread south, but slower than shown by the GFS which
again seems to be a fast outlier. The showers will get here during
the night except possibly along the Nevada border. Showers will
shift eastward across Idaho zones Thursday morning then decrease
from west to east Thursday afternoon. Air mass looks too stable for
thunderstorms. Breezy and cooler Thursday, but still warmer than
normal for mid-March.

.Thursday night through Tuesday...Dry weather and temperatures
10-15 degrees above normal will accompany an upper ridge on Friday.
An upper trough will enter the PacNW next weekend, bringing with it
showers and a cooling trend. Snow levels near 9000 ft MSL on
Saturday will lower to around 7000 feet MSL on Sunday. A second
trough will enter the far western U.S. early next week for a chance
of showers across SE Oregon and SW Idaho. Snow levels will range
from 6000-7000 feet MSL. Temperatures will average 5 degrees above
normal Sunday through Tuesday

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Wednesday Wednesday Night Thursday
Weather: Showers, mainly after noon. High near 49. Light south southeast wind becoming south 5 to 10 mph in the afternoon. Chance of precipitation is 80%. Showers. Low around 37. South wind around 10 mph. Chance of precipitation is 100%. Showers likely, mainly before noon. Mostly cloudy, with a high near 44. South southwest wind around 10 mph. Chance of precipitation is 60%.
Temperatures: high 49 deg. F. low 37 deg. F. high 44 deg. F.
Wind direction: south-southeast south south-southwest
Wind speed: 5-10 10 10
Expected snowfall: 0 in. 0 in. 0 in.
Granite Mountain at 7700 feet.
  Wednesday Wednesday Night Thursday
Weather: Scattered rain showers before noon, then rain and snow showers. High near 39. Breezy, with a southwest wind 14 to 21 mph. Chance of precipitation is 80%. Total daytime snow accumulation of less than a half inch possible. Rain and snow showers. Low around 29. Breezy, with a south southwest wind 17 to 25 mph, with gusts as high as 34 mph. Chance of precipitation is 100%. New snow accumulation of less than one inch possible. Snow showers, mainly before noon. High near 31. Southwest wind 16 to 18 mph. Chance of precipitation is 80%. New snow accumulation of 1 to 3 inches possible.
Temperatures: high 39 deg. F. low 29 deg. F. high 31 deg. F.
Wind direction: southwest south-southwest southwest
Wind speed: 14-21 17-25 16-18
Expected snowfall: Less than one half in. less than one in. 1-3 in.

This avalanche advisory is provided through a partnership between the Payette National Forest and the Payette Avalanche Center. This advisory covers the West Central Mountains between Hard Butte on the north and Council Mountain on the south. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires at midnight on the posted day unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.