THIS AVALANCHE ADVISORY EXPIRED ON February 19, 2016 @ 6:42 am
Avalanche Advisory published on February 18, 2016 @ 6:42 am
Issued by -
bottom line

The avalanche danger today is CONSIDERABLE for all elevations and aspects. Rain saturated snow below 7,000, and today's heavy snow and strong winds above 7,000 will make natural avalanches possible and human caused avalanches likely. Careful snowpack evaluation, cautious route finding, and conservative decision making are essential. If forecasted snow and winds come to fruition, HIGH avalanche danger will be found by afternoon above 7,000 feet on the north half of the compass.

How to read the advisory


  • Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Storm Slab
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Over the next 24 hours we will be seeing up to 10 inches (1 inch water) or more of snow in the high elevations of the forecast area. The rapid rate of snowfall today, combined with strong winds will make for dangerous avalanche conditions. Conservative decision making today will be important. Stick to low angle terrain, choose terrain that is not below any steep avalanche paths, ride one at a time up/down slopes, and keep an eye on your backcountry partners.

Avalanche Problem 2: Loose Wet
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It is currently raining below 7,000 feet. This rain combined with lack of hard freezing temps the last few days and nights could tip the balance on any slopes in avalanche terrain today. It is easy to avoid these slopes currently, but if the snowline drops as forecasted it is going to be a good idea to rember that below the fresh snow is a soggy/saturated snowpack and not be swayed by the presence of fresh snow.

Avalanche Problem 3: Persistent Slab
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Triggering a slab due to this weak layer has become more difficult over the last two and a half weeks, but I would not let my guard down, We are still finding this weak layer in upper elevation wind protected terrain. Pit results and stability testing are pointing toward less likelihood of triggering, but if triggered we are still talking about a potentially unsurvivable hard slab avalanche. Take the time to carefully assess terrain choices on the north half of the compass today. Especially areas where the snow cover is thinner which allows the buried surface hoar to be closer to the surface, and in turn more reactive---especially for snowmachines. This is the same layer that was the cause of the fatal avalanche on January 31st. A persistent weak layer such as this is a low probablility, but HIGH CONSEQUENCE scenario.  In addition, the old snow layer around 55cm is still showing signs of instability in our pit tests with moderate test scores.  This layer is comprised of grauple in some areas and has buried Surface Hoar and fine grained facets mixed in in other areas.

advisory discussion

Boy howdy...winter is back, for a few days at least. Be sure to stay safe and not succomb to powder fever over the next 24-48 hours. Treat today's storm with respect and stick to low angle terrain and enjoy!

BACKCOUNTRY FILM FESTIVAL!

Come join Friends of Payette Avalanche Center, McCall Winter Sports Club, and Brundage Mountain to celebrate this weekends powder skiing with a night of backcountry films.

Tomorrow night at McCall Golf Course Clubhouse!

Doors open at 6 pm and the show will start at 7 pm.

Please come out and share your stoke!

recent observations

The past few days the snowpack has been soggy and uninspiring. Wet slides, roller balls, crusts, and sticky snow have been the norm the last few days. Things should change today...at upper elevations at least. 

weather

It is shaping up to be a windy and wet day in the West Central Mountains today. Currently precip is falling as rain up to ~7,000 feet and an inch of snow has fallen above 7,000 as of 5:30 am. However, snow line is forecasted to drop through the day as a vigorous upper level trough pushes in a cold front form the Northwest. We could receive 5-10 inches (or more) of snow over the next 24 hours with winds blowing out of the south-south west at 20-30 mph and gusting to near 50 mph at the highest elevations. Showers should continue on and off through the weekend with a ridge of high pressure returning early next week.

 

Two-Day Mountain Weather Forecast Produced in partnership with the NOAA-NWS
McCall Airport at 5021 feet.
  Thursday Thursday Night Friday
Weather: Rain showers before 11am, then snow showers between 11am and 2pm, then rain and snow showers after 2pm. Some thunder is also possible. High near 36. South wind 10 to 15 mph. Chance of precipitation is 100%. New snow accumulation of less than one inch possible. Snow showers likely. Cloudy, with a low around 29. Breezy, with a south southwest wind 16 to 21 mph decreasing to 7 to 12 mph after midnight. Winds could gust as high as 30 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 2 inches possible. Snow showers likely, mainly after 11am. Cloudy, with a high near 40. South wind 5 to 9 mph. Chance of precipitation is 60%. New snow accumulation of less than a half inch possible.
Temperatures: High 36 deg. F. Low 29 deg. F. High 40 deg. F.
Wind direction: South South-southwest South
Wind speed: 10-15 7-12 5-9
Expected snowfall: Less than one inch in. 1-2 in. Less than half an inch in.
Granite Mountain at 7700 feet.
  Thursday Thursday Night Friday
Weather: Snow showers. Some thunder is also possible. Temperature falling to around 21 by noon. Windy, with a south southwest wind 28 to 38 mph, with gusts as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 7 inches possible. Snow showers. Temperature rising to around 30 by 3am. Windy, with a southwest wind 37 to 47 mph decreasing to 22 to 32 mph after midnight. Winds could gust as high as 65 mph. Chance of precipitation is 80%. New snow accumulation of 2 to 4 inches possible. Snow showers likely. Cloudy, with a high near 36. Windy, with a south wind 21 to 30 mph, with gusts as high as 44 mph. Chance of precipitation is 60%. New snow accumulation of 1 to 3 inches possible.
Temperatures: Falling to 21 deg. F. Rising to 30 deg. F. High 36 deg. F.
Wind direction: South-southwest Southwest South
Wind speed: 28-38 gust to 55 22-32 gusts to 65! 21-30 gusts to 44
Expected snowfall: 3-7 in. 2-4 in. 1-3 in.
Disclaimer

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.