Kootenai National Forest Avalanche Advisory – 2/28/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Feb. 28, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Tuesday, March 4, 2014 by Jon Jeresek.


MOUNTAIN WEATHER 

WeatherGraphic

Since the Tuesday AM (February 25st) advisory, light amounts of snow (SWE 0.1”- 0.5”) have fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).  Winds Tuesday through Thursday were light with NO snow transport.  Temperatures at all sites have been below freezing for the last three days.  There is abundant soft snow available for wind transport at all sites in our Ranges.

FORECAST:  Mostly cloudy skies Friday through Sunday.  All daytime temperatures are forecasted to be well below freezing, with night time temperatures -10’ to -20’F.  Winds will be out of the northeast at 14 – 17 mph with HIGH probability of snow transport Friday through Saturday.  Chance of snow is 30 – 80% Friday AM through Sunday, with MODERATE accumulations of 5” – 9” forecasted.


 RECENT OBSERVATIONS

RecentObservationsGraphic

We traveled to Whoopee Basin in the West Cabinets located 27 air miles southwest of Libby on February 27th.  85” to 90” of snow was encountered on south aspects at 5,500’ elevation.  Upper levels of the snowpack have settled and consolidated into hard slab layers.  The top 25” of the snowpack consists of nine discernable layers and is quite complex.  The top 20” of this snowpack released at multiple levels with moderate force during compression tests and stuff block tests.  Below these surface layers are hard slabs which release cleanly with hard force.  The base of the snowpack shows depth hoar development as a result of the severe temperature gradients during the first week of February.  Currently, there are NO significant temperature gradients in the snowpack to drive change processes.     

DSCF3208

Loose snow sluff triggered by snowball falling out of tree. This was very common Tuesday-Wednesday when days were clear/sunny/warm.

 

DSCF3209

Look closely at the ridgeline to see the crown fracture for a snowmobile triggered avalanche in Whoopee Basin on Sunday 2/16/2014. There is a secondary crown line under the cliffs.

 


  SNOWPACK DISCUSSION

Avalanche Problem #1

 

Storm Snow

We have experienced exceptional storm loading through 02/21/2014.  All the incidents I have investigated involved soft slab releases on old snow surfaces.  Normally storm slab problems persist for a couple of days, however, we have transitioned from one storm cycle to the next without break.  You can reduce your risk from storm slabs by waiting +48 hours before venturing out into the backcountry.  ALL avalanche terrain (starting zones, tracks, and run outs) should be avoided.

 


 Avalanche Problem #2 

Wind Slab

We have abundant soft snow available for wind transport.  Northeast transport winds of 14 -17 mph are forecasted through Saturday.  This will result in wind slabs and pillows on southwest aspects.  Southwest winds transported MUCH snow through Wednesday 02/19/2014.  Wind slabs and pillows formed on northeast and east aspects near ridge tops.  Both locations should be identified and avoided.    

 

 

 


 

MODERATE storm loading (5” – 9”) in the forecast through Sunday.  We expect HIGH wind transport (NE 14 -17 mph) of available snow Friday through Saturday.  Temperatures are forecasted to be well below freezing daytime, and night time in the -10’F to -20’F through Sunday.  The trend is for RISK TO INCREASE through this period. 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is HIGH.  This means that very dangerous avalanche conditions exist on many terrain features, such as steep semi open slopes.  Natural avalanches are likely, and human triggered avalanches are very likely.  Backcountry travel in ANY avalanche terrain is NOT recommended.

SPECIAL NOTE:  The National Weather Service is issuing a warning for “EXTREMELY DANGEROUS BACKCOUNTRY CONDITIONS THROUGH SUNDAY”.  Blizzard conditions, bitterly cold temperatures, low visibility will make travel conditions extremely dangerous.  The final incident report for the 22 February 2014 avalanche fatality north of Spar Peak is available on the Flathead Avalanche Center website.


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

Kootenai National Forest Avalanche Advisory – 2/25/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Feb. 25, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Friday, February 25, 2014 by Jon Jeresek.


MOUNTAIN WEATHER 

WeatherGraphic

Since the Friday AM (February 21st) advisory, light amounts of snow (SWE 0.1”- 0.3”) have fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake)  Poorman Creek received 0.9” SWE.  Winds Friday through Sunday were light with no snow transport.  Temperatures at all sites have been below freezing for the last four days.  There is abundant soft snow available for wind transport at all sites in our mountain ranges.

FORECAST:  Partly cloudy skies Tuesday through Thursday.  All daytime high temperatures are forecasted to be just below freezing, with night time temperatures in the teens.  Winds will be out of the southeast at 3 – 5 mph with NO probability of snow transport Tuesday through Thursday.  Chance of snow is 40 – 50% Wednesday PM through Thursday, with light accumulations of trace – 1” forecasted.


 RECENT OBSERVATIONS

RecentObservationsGraphic

We traveled to the upper Beetle Creek incident site in the Purcells located 55 air miles northwest of Libby on February 24th.  (On Monday, February 17th three snowmobilers triggered a slide that partially buried one rider and buried three machines.)  95” to 100” of snow was encountered on northeast aspects at 5,500’ elevation.  10” very soft snow sits atop a 23” hard slab (1 finger/pencil).  The top 33” of this snowpack released with a five wrist taps during compression tests.  Below these surface layers are hard slabs which release cleanly with hard force.  The base of the snowpack shows depth hoar development as a result of the severe temperature gradients of 20 days ago.  Currently, there are NO significant temperature gradients in the snowpack to drive change processes. 

I am investigating four snowmobile/avalanche related incidents from Sunday 02/16/2014 through Sunday 02/23/2014.  One incident on Saturday, February 22 resulted in a fatality. We extend our deepest condolences to the family and friends of those involved. Those reports will be posted with the Flathead Avalanche Center as soon as I can finalize them.

 

This pic shows the pit dug adjacent to the 2-17-2014 slide that partially buried 1 rider and 3 machines.  The failing layer is at a depth of  33”, and failed on decomposing surface hoar, shear was easy and Quality 1. 2/24/2014

This pic shows the pit dug adjacent to the 2-17-2014 slide that partially buried 1 rider and 3 machines. The failing layer is at a depth of 33”, and failed on decomposing surface hoar, shear was easy and Quality 1. 2/24/2014

 

 

 

 

 

 

 

 

 

 


  SNOWPACK DISCUSSION

Avalanche Problem #1

 

Storm Snow

We have experienced exceptional storm loading through 02/18/2014.  All the incidents I have investigated involved soft slab releases on old snow surfaces.  Normally storm slab problems persist for a couple of days, however, we have transitioned from one storm cycle to the next without break.  You can reduce your risk from storm slabs by waiting +48 hours before venturing out into the backcountry.  ALL avalanche terrain (starting zones, tracks, and run outs) should be avoided.

 


 Avalanche Problem #2 

Wind Slab

We have abundant soft snow available for wind transport.  Southwest winds transported MUCH snow through Wednesday 02/19/2014.  Wind slabs and pillows formed on northeast and east aspects near ridge tops.  These locations should be identified and avoided.

 

 

 


 

Avalanche Problem #3

Persistent Slab

Weak snow (facets and even surface hoar) exist deeper in the snowpack. These layers are dangerous and when they fracture can propagate far and wide. Some of these weak layers are buried 3 to 4 feet or deeper in the snowpack, and can be triggered from flat runout zones. ALL avalanche terrain (starting zones, tracks, and run outs) should be avoided. These layers have been the culprit in recent avalanches in the region.

 

 

 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is HIGH.  This means that very dangerous avalanche conditions exist on many terrain features, such as steep semi open slopes.  Natural avalanches are likely, and human triggered avalanches are very likely.  Backcountry travel in ANY avalanche terrain is NOT recommended.

SPECIAL NOTE:  Tragically, we assisted with an avalanche fatality on Saturday in the Spar Peak region of the West Cabinets near the Montana-Idaho border. We extend our deepest condolences to the family and friends of those involved.  We learned of a complete avalanche burial on Sunday in the China Basin area of the Purcells.  Thankfully, that snowmobiler was recovered uninjured. 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

Kootenai National Forest Avalanche Advisory- 2/21/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Feb. 21, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Friday, February 25, 2014 by Jon Jeresek.


MOUNTAIN WEATHER 

WeatherGraphic

Since the Tuesday AM (February 18th) advisory, HEAVY amounts of snow (SWE 0.9” – 1.9”) have fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).  Winds Tuesday and Wednesday were strong out of the southwest with HIGH amounts of snow transport.  Temperatures at all sites have been below freezing for the last three days.  There is abundant soft snow available for wind transport at all sites in our Ranges.

 

FORECAST:  Mostly cloudy skies Friday through Sunday.  All daytime high temperatures are forecasted to be below freezing, with night time temperatures in the lower teens.  Winds will be out of the west at 8 – 12 mph with LOW probability of snow transport Friday and Saturday. Sunday winds will switch to the east 6 – 12 mph.  Chance of snow is 50 – 80% Friday AM through Sunday, with LIGHT accumulations of 3”- 7” forecasted.


 RECENT OBSERVATIONS

RecentObservationsGraphic

We traveled to Scenery Ridge in the East Cabinets located 7 air miles west of Libby on February 20th.  55” to 60” of snow was encountered on east aspects above 5,500’ elevation.  Abundant very soft snow sits atop a 4” hard slab (1 finger) overlaying a 13” soft slab (4 finger).  The top 32” of this snowpack released with a single wrist tap during compression tests.  Below these surface layers are hard slabs which release cleanly with moderate force.  The base of the snowpack shows depth hoar development as a result of the severe temperature gradients of 2 weeks ago.  Currently, there are NO significant temperature gradients in the snowpack to drive change processes.  

 I investigated three snowmobile related avalanche incidents from Sunday and Monday (2-16/17-2014).  I am not receiving any new reports.  Information within our snowmobile community is shared rapidly.  I am certain the word is out concerning our treacherous snowpack conditions.

WeakCrystals

Weak Crystals

 

Turner

Turner Wind

 

Q1 Shear

Q1 Shear

 

Depth Hoar

Depth Hoar


  SNOWPACK DISCUSSION

Avalanche Problem #1

Storm SnowWe have experienced exceptional storm loading for the last nine days.  All the incidents I have investigated involved soft slab releases on old snow surfaces.  Normally storm slab problems persist for a couple of days, however, we have transitioned from one storm cycle to the next without break.  You can reduce your risk from storm slabs by waiting +48 hours before venturing into steep terrain 


 Avalanche Problem #2 

Wind SlabWe have abundant soft snow available for wind transport.  Southwest winds Tuesday and Wednesday transported MUCH snow.  Wind slabs and pillows formed on northeast and east aspects near ridgetops.  These locations should be identified and avoided. 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is HIGH.  This means that very dangerous avalanche conditions exist on many terrain features, such as steep semi open slopes.  Natural avalanches are likely, and human triggered avalanches are very likely.  Backcountry travel in avalanche terrain is NOT recommended.

 SPECIAL NOTE:  The Kootenai Region has received heavy storm loading since our last advisory (Tuesday 2-18-2014).   On Tuesday-Wednesday 2-18/19-2014, we experienced wind transport at all locations. 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

Kootenai National Forest Avalanche Advisory – 2/18/2014

THIS ADVISORY HAS EXPIRED

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

Issued: Feb. 18, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Friday, February 21, 2014 by Jon Jeresek.


MOUNTAIN WEATHER 

WeatherGraphic

Since the Friday AM (February 14th) advisory, VERY HEAVY amounts of snow (SWE 1.5” – 4.2”) have fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).  Winds Sunday were strong out of the west/southwest with very high amounts of snow transport.  Most temperatures at all sites have been below freezing for the last four days.  However, a couple sites did show temperatures in the 33° – 34° F range on Saturday PM.  There is abundant soft snow available for wind transport.

FORECAST:  Mostly cloudy skies Tuesday through Thursday.  All daytime high temperatures are forecasted to be below freezing, with night time temperatures in the upper teens.  Winds will be out of the southwest at 14 – 20 mph with high probability of snow transport Tuesday and Wednesday.  Chance of snow is 80 -100% Tuesday AM through Thursday, with HEAVY accumulations of 16- 27 inches forecasted.


 

RECENT OBSERVATIONS

RecentObservationsGraphic

We traveled to the Keeler-Rattle Divide in the West Cabinets located 28 air miles west of Libby on February 17th.  115  to 120 inches of snow was encountered on east aspects above 5,800’ elevation.  Abundant very soft snow (+20 inches) sits atop a 5 inch hard slab (1 finger).  These described layers release easily and cleanly on a 2 inch knife hard crust.  Our benchmark layer in the snowpack is the wind event of January 11th that deposited needles, moss, and pink Palousse dust.  Below these surface layers are hard slabs which release cleanly with moderate force.  The base of the snowpack shows depth hoar development as a result of the severe temperature gradients of 10 days ago.  Currently, there are NO significant temperature gradients in the snowpack to drive change processes. 

I received reports from snowmobilers who traveled to the East/West Cabinets or Purcells on Sunday.  All reported observing natural releases or triggering releases.  Overnight the Kootenai region received HEAVY storm loading accompanied by southwest transport winds at ridgetop locations.

 

 20140217KeelerPit2

 

 

 

 

 

 

 

 

 

 

  


 

 SNOWPACK DISCUSSION

Avalanche Problem #1

Wind Slab

We have abundant soft snow available for wind transport.  West/southwest winds at 15 – 25 mph all day Sunday transported MUCH snow.  Wind slabs and pillows formed on northeast and east aspects near ridgetops.  These locations should be identified and avoided.

 

 

 


 

Avalanche Problem #2 

Loose Dry

We have abundant very soft snow deposited from the February 16th-17th storm event.  Much more snow (16–27 inches) is in the forecast.  Release of this unconsolidated snow is usually harmless to people.  However, larger sluffs can carry people into terrain traps (gullies, cliffs, rocks).  Avoid travelling above terrain traps when Loose Dry avalanches are likely.

 

 

TREND:  VERY HEAVY storm loading (16- 27 inches) in the forecast through Thursday.  We expect HIGH wind transport (SW 14- 20 mph) of available snow Tuesday and Wednesday.  Temperatures (day time) are forecasted to be below freezing and night time in upper teens through Thursday.  The trend is for hazard to remain high and increase through this period. 

 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is HIGH.  This means that very dangerous avalanche conditions exist on many terrain features, such as steep semi open slopes.  Natural avalanches are likely, and human triggered avalanches are very likely.  Backcountry travel in avalanche terrain is NOT recommended.

SPECIAL NOTE:  The Kootenai Region has received exceptional storm loading since our last advisory (Friday 2-14-14).   On Sunday 2-16-14, we experienced wind transport at all locations all day long.  Today we are receiving reports from back country travelers into all of our Ranges who have observed natural releases or triggered releases.

 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

 

Kootenai National Forest Avalanche Advisory – 2/14/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Feb. 14, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Tuesday, February 18, 2014 by Jon Jeresek.


MOUNTAIN WEATHER 

WeatherGraphic

Since the Tuesday AM (February 11th) advisory, heavy amounts of snow (SWE 0.9” – 1.7”) fell at Kootenai SNOTEL sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).  Winds have been strong out of the west/southwest with lots of wind transported snow.  Most temperatures at all sites have been below freezing for the last three days.  However, a couple of sites did show temperatures in the 33° – 34° F range on Wednesday afternoon.  

FORECAST:  Mostly cloudy skies Friday through Sunday.  All daytime high temperatures are forecasted to be just above freezing, with night time temperatures in the mid 20s.  Winds will be out of the southwest at 17- 22 mph with a high probability of snow transport Friday and Sunday.  Chance of snow is 70 -100% Friday afternoon through Sunday, with heavy accumulations of 12”- 20” forecasted.


 

RECENT OBSERVATIONS

RecentObservationsGraphic

We traveled to Blue Mountain 6,040’ in the Purcell Range located 9 air miles northeast of Libby on February 13th.  45 to 50 inches of snow was encountered on west aspects above 6,000’ elevation.  Abundant very soft snow (8 inches) sits atop a 4 inch soft slab (4 finger).  These layers release easily and cleanly on a one finger hard slab.  Our benchmark layer in the snowpack is the wind event of January 11th that deposited needles and moss.  Below these surface layers are hard slabs which release cleanly with moderate to hard force in stability tests.  The base of the snowpack shows depth hoar development as a result of the severe temperature gradient from a week ago.  Currently, there are NO significant temperature gradients in the snowpack to drive change processes. 

Riders in the Cabinet Mountains near Rattlesnake Mountain observed no fresh avalanche activity. However, they reported frequent cracking and whumpfing of the snowpack and sensitive wind loaded slopes. 

3-4 mm depth hoar near bottom of snowpack. 2/13/2014.

Depth hoar. 2/13/2014.

 

Wind drift on road as a good example of wind loading occurring in the region. 2/13/2014.

Wind drift on road as a good example of wind loading occurring in the region. 2/13/2014.

 

 

 

 

 

 

 

 

 

 

 

  


 

 SNOWPACK DISCUSSION

Avalanche Problem #1

Wind Slab

We have abundant soft snow available for wind transport. West – southwest winds at 15 – 25 mph Wednesday afternoon through Thursday transported a lot of snow.  Wind slabs and pillows formed on northeast and east aspects near ridgetops.  These locations should be identified and avoided.

 

 

 


 

Avalanche Problem #2 

Loose Dry

We have abundant very soft snow deposited from the February 10 – 12 storm event.  Much more snow (12”– 20”) is in the forecast in the next few days.  Release of this unconsolidated snow is usually harmless to people.  However, larger sluffs can carry people into terrain traps (gullies, cliffs, rocks).  Avoid travelling above terrain traps when Loose Dry avalanches are likely. 

 

 

 TREND:  Very HEAVY storm loading (12”- 20”) in the forecast through Sunday.  We expect HIGH wind transport (SW 17- 22mph) of available snow Friday through Sunday.  Temperatures (day time) are forecasted to be just above freezing and night time in mid 20s F through Sunday.  The trend is for avalanche hazard to increase through this period. 

 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is CONSIDERABLE.  This means that dangerous avalanche conditions exist on many terrain features, such as steep, unanchored slopes.  Natural avalanches are possible and human triggered avalanches are likely.  Backcountry travelers should evaluate snow and terrain carefully, exercise caution in route finding, and be conservative in decision making. West – southwest winds transported snow in the last 24 hours.  Wind slabs and pillows overlay weak surface layers from our arctic weather of a week ago.  Wind deposits should be identified and avoided.

 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

 

Kootenai National Forest Advisory – 2/11/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Feb. 11, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Friday, February 14, 2014 by Jon Jeresek.


MOUNTAIN WEATHER 

WeatherGraphic

Since the Friday (February 7th) advisory, light snow has fallen at most Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake). Poorman Creek is the exception with 0.9″ of SWE since yesterday morning. Winds have been light out of the east with little or NO snow transport.  All temperatures at all sites have been below freezing for the last four days, with overnight lows ranging from 0’ to -5’F.  There is abundant soft snow available for wind transport.

FORECAST:  Mostly cloudy skies Tuesday through Thursday.  All temperatures are forecasted to be below freezing, with none breaking the freezing mark.  Winds will be out of the west/southwest at 9 – 27 mph with HIGH probability of snow transport through Wednesday.  Chance of snow is 100% Tuesday AM through Wednesday AM, and 80% Wednesday PM into Thursday, with 17- 30” accumulations forecasted.


 

RECENT OBSERVATIONS

RecentObservationsGraphic

We traveled to Poorman Basin 5,500’ in the East Cabinets located 18 air miles south of Libby on February 10th.  80” to 85” of snow was encountered on southeast aspects above 5,500’ elevation.  Abundant very soft snow (13”) sits atop a 4” soft slab (4 finger) and a 5” hard slab (1 finger).  These described layers release easily and cleanly on a pencil hard crust layer.  Our benchmark layer in the snowpack is the wind event of January 11th that deposited needles and moss.  Below these surface layers are hard slabs which release cleanly with hard force.  There is a significant temperature gradient in the snowpack from the surface (-4’C) down 4” (-8’C) to drive change processes. 

Enroute to pit sites, I photographed a soft slab crown fracture from last weekend below 5,500’ elevation on a steep north aspect.  It appears to have been triggered by a point release sluff from just above the crown, estimate 75-100’ upslope distance.  While digging a data pit, I heard a muffled “rumble” that I thought may have been ridge top winds.  It was snowing lightly (1/2”/hour), so visibility was poor.  As I traveled out of the basin, I looked more closely and found the “rumble” source.  It was a soft snow sluff that traveled several hundred yards on a steep north aspect just east of the crown fracture I photographed.   

 

Depth hoar +4mm. 2/10/2014.

Depth hoar +4mm. 2/10/2014.

Poorman 005

Cable Mtn 6,860’ guarding the entrance to Poorman Basin. 2/10/2014.

Cable Mtn 6,860’ guarding the entrance to Poorman Basin. 2/10/2014.

 

Investigating the depth hoar formation below the November 19th rain crust. 2/10/2014.

Investigating the depth hoar formation below the November 19th rain crust. 2/10/2014.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 SNOWPACK DISCUSSION

Avalanche Problem #1

Wind Slab

We have abundant soft snow available for wind transport.  More HEAVY storm loading (17 – 30”) is in the forecast.  West/southwest winds forecasted at 14 – 27 mph Tuesday through Wednesday will transport snow.  Wind slabs and pillows will form on northeast and east aspects near ridgetops.  These locations should be identified and avoided.

 

 

 


 

Avalanche Problem #2 

Loose Dry

We have abundant very soft snow deposited from the January 29th-30th storm event.  Much more snow (17 – 30”) is in the forecast.  Release of this unconsolidated snow is usually harmless to people.  However, larger sluffs can carry people into terrain traps (gullies, cliffs, rocks).  Avoid travelling above terrain traps when Loose Dry avalanches are likely. 

 

 

 

 

TREND:  Very HEAVY storm loading in the forecast through Thursday.  We expect a lot of wind transport of available snow Tuesday through Wednesday.  All temperatures (day and night) are forecasted to be below freezing through Thursday.  The trend is for the avalanche hazard to rise through this period. 

 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is MODERATE this morning and could easily rise to CONSIDERABLE today. This means that heightened avalanche conditions exist on specific terrain features, such as steep unanchored slopes, but could rise to dangerous avalanche conditions if forecasted snow amounts come to fruition.

SPECIAL NOTE:  We have abundant very soft snow available for wind transport.  We have a lot more snow in the forecast (17– 30”) along with transport winds (SW 14 – 27mph).  Conditions will change rapidly – stay alert, be conservative in your decision making. 

 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

 

Kootenai National Forest Avalanche Advisory – 2/7/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Feb. 7, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Tuesday, February 11, 2014. 


MOUNTAIN WEATHER 

WeatherGraphic

Since the Tuesday AM (February 4th) advisory, NO snow (0.0” SWE) has fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).  Winds have been light out of the east with little or NO snow transport.  All temperatures at all sites have been below 0’F for the last three days, with overnight lows ranging from -15’ to -21’F.  There is an abundant amount of soft snow available for wind transport.

FORECAST:  Mostly cloudy skies Friday through Sunday.  All temperatures are forecasted to be above zero, but with none breaking the freezing mark (A VIRTUAL HEAT WAVE!).  Winds will be out of the east at 2 – 4 mph then switching to the west with NO probability of snow transport through Sunday.  Chance of snow is 40% Friday AM, and 30% Saturday PM into Sunday AM, with 1-2” accumulations forecasted.


 

RECENT OBSERVATIONS

RecentObservationsGraphic

We traveled to Whoopee Basin 6,000’ in the West Cabinets located 19 air miles southwest of Libby on February 6th.  75” to 80” of snow was encountered on east aspects above 6,000’ elevation.  Abundant very soft snow (12”) sits atop a 2” soft slab (4 finger).  These described layers release easily but NOT cleanly.  Our benchmark layer in the snowpack is the wind event of January 11th that deposited needles, moss, and pink clay dust scoured off the Palousse in Idaho.  Below these surface layers are hard slabs which release cleanly with hard force.  There is a VERY significant temperature gradient in the snowpack from the surface (-22’C) down 12” (-12’C) to drive change processes.

Report from a snowmobiler riding in the West Cabinets:  4 ski bikes made staggered diagonal ascending cuts across the steep open face of Benning Mountain without incident.  This is the first activity on this terrain feature this year. 

Spar Peak on way to Whoopee Basin in West Cabinets. 2/6/2014.

Spar Peak on way to Whoopee Basin in West Cabinets. 2/6/2014.

 

Snowshoe and A Peak in the East Cabinets as seen from Whoopee Basin. 2/6/2014.

Snowshoe and A Peak in the East Cabinets 2/6/2014.

 

Greatest temperature gradient I have observed in a snowpack since 1987 (ten degrees over 8” depth). 2/6/2014.

Temperature Gradient. 2/6/2014.

 

 

 

 

 

 

 

 


 

 SNOWPACK DISCUSSION

Avalanche Problem #1

Persistent Slab

We have been tracking this hard slab in the upper third of the snowpack for several weeks now.  It usually releases with moderate force and cleanly on large angular blocks.   As this slab gets buried under successive storms, we expect this slab to be problematic in a tricky way.

 

 

 


 

Avalanche Problem #2 

Loose Dry

We have abundant very soft snow deposited from the January 29th-30th storm event.  Release of this unconsolidated snow is usually harmless to people.  However, larger sluffs can carry people into terrain traps (gullies, cliffs, rocks).  Avoid travelling above terrain traps when Loose Dry avalanches are likely. 

 

 

 

TREND:  NO storm loading in the forecast through Sunday.  We expect NO wind transport of available snow Friday through Sunday.  All temperatures (day and night) are forecasted to be above zero through Sunday.  The trend is for risk to decrease by the end of this period.

 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is MODERATE.  This means that heightened avalanche conditions exist on specific terrain features, such as steep unanchored slopes.  Natural avalanches are unlikely, however human triggered avalanches are possible.  Backcountry travelers should evaluate snow and terrain carefully, and identify features of concern.

SPECIAL NOTE:  The wind transport that was forecasted Tuesday through Thursday did not materialize.  Bitterly cold temperatures came in Monday PM and will persist through Friday PM.  These cold temperatures complicate all issues you will deal with outdoors. 

 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

 

Kootenai National Forest Avalanche Advisory – 2/4/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Feb. 4, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Friday, February 7, 2014. 


MOUNTAIN WEATHER 

WeatherGraphic

Since the Friday AM (January 31st) advisory, light snow (0.1” – 0.3” SWE) has fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).  Most of this snowfall came Sunday afternoon through Monday morning.  Winds have been light out of the north and east with no snow transport.  All temperatures at all sites have been below freezing, with a high of 21’F at the Poorman site.  There is an abundant amount of soft snow available for wind transport.

FORECAST:  Mostly cloudy Tuesday trending to mostly clear skies Thursday.  Temperatures will be VERY  FRIGID with daytime highs just above zero.  Winds will be out of the east at 11 – 18 mph with HIGH probability of snow transport through Thursday.  Chance of snow is 0% through Thursday, with NO accumulations forecasted.


 

RECENT OBSERVATIONS

RecentObservationsGraphicWe traveled to Banfield Mountain 6,100’ in the Purcells located 12 air miles north of Libby on February 3rd.  50” to 55” of snow was encountered on south aspects above 6,000’ elevation.  Abundant very soft snow (8”) sits atop a 3” pencil/knife hard crust.  These described layers release easily but NOT cleanly.  Our benchmark layer in the snowpack is the wind event of January 11th that deposited needles, moss, etc.  However, at this site I did NOT find any pink clay dust scoured off the Palousse in Idaho.  Below these surface layers are hard slabs which release cleanly with hard force.  There is a significant temperature gradient in the snowpack from the surface (-8.5’C) down 8” (-5’C) to drive change processes

 

Snow pit profile showing abundant soft snow atop the January 11th wind event. 2/3/2014.

Snow pit profile showing abundant soft snow atop the January 11th wind event. 2/3/2014.


Banfield Mtn snotel site at 5,600’ (snow pillow, snow depth sensor, precip guage, instrument shelter, antenna tower. 2/3/2014.

Banfield Mtn snotel site at 5,600’ (snow pillow, snow depth sensor, precip guage, instrument shelter, antenna tower. 2/3/2014.


Lake Koocanusa as seen from Banfield Mtn 6,100’. 2/3/2014.

Lake Koocanusa as seen from Banfield Mtn 6,100’. 2/3/2014.

 

 

 

 

 

 

 

 

 


 SNOWPACK DISCUSSION

Avalanche Problem #1

Wind Slab

Our storm event of January 29-30th deposited abundant very soft snow.  This snow is available for wind transport.  Wind transport is forecasted for Tuesday through Thursday with easterly winds of 11- 18 mph.  Leeward slope loading on the WEST SIDE of ridges is an unusual event for us. 

 

 

 


 

Avalanche Problem #2 

Persistent Slab

We have been tracking this hard slab in the upper third of the snowpack for several weeks now.  It usually releases with moderate force and cleanly on large angular blocks.   As this slab gets buried under successive storms, we expect this slab to be problematic in a tricky way.

 

 

 

We expect wind transport of available snow Tuesday through Thursday.  Daytime high temperatures are forecasted to be just above zero through Thursday.  The trend is for avalanche hazard to increase by the end of this period. 

 


  BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is MODERATE.  This means that heightened avalanche conditions exist on specific terrain features, such as steep unanchored slopes.  Natural avalanches are unlikely, however human triggered avalanches are possible.  Backcountry travelers should evaluate snow and terrain carefully, and identify features of concern.

SPECIAL NOTE:  We experienced significant storm loading at all sites late last week.  Abundant soft snow is available for wind transport.  Wind transport is forecasted Tuesday through Thursday.  Watch the weather and avoid recently wind loaded slopes.

 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

 

Kootenai National Forest Avalanche Advisory – 1/31/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED

Issued: Jan. 31, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Tuesday, February 4, 2014. 


MOUNTAIN WEATHER 

WeatherGraphic

Since the Tuesday AM (January 28th) advisory, moderate to heavy snow (0.6” – 1.2” SWE) has fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).  Snowfall started Wednesday AM and continues through Friday.  Winds have been very light out of the southwest with NO snow transport.  Forecasted transport winds for Thursday did not arrive.  All temperatures at all sites have been below freezing.  This most recent storm event came in semi warm and finished cold.

FORECAST:  Partly cloudy trending to mostly cloudy skies Friday through Sunday.  Temperatures will be below freezing and drop to low teens at night.  Winds will be out of the southwest at 2 – 5 mph with NO probability of snow transport through Sunday.  Chance of snow is 30% Friday and 50% Sunday with NO accumulations forecasted.


 

RECENT OBSERVATIONS

RecentObservationsGraphicWe traveled to Bear Creek Basin 5,500’ in the East Cabinets located 15 air miles south of Libby on January 30th.  70” to 75” of snow was encountered on south aspects above 5,500’ elevation.  The most recent storm came in warm and finished cold.  A three inch soft slab formed at the front end of this storm and was topped with another seven inches of very soft snow.  These two layers sit atop a one inch surface hoar layer that developed over several nights during our mountain fog cycle last week.  These snow layers release very easily with clean shear planes.  Our new benchmark layer in the snowpack is the wind event of January 11th that deposited needles, etc and pink clay dust scoured off the Palousse in Idaho.  Below these surface layers are hard slabs which release cleanly with hard force.  There is NO significant temperature gradient in the snowpack to drive change processes. 

 Bear Basin 005a

The persistent slab shear plane and block.  Do you see the January 11th wind event above it? 1/30/2014.

The persistent slab shear plane and block. Do you see the January 11th wind event above it? 1/30/2014.


Our new snowpack benchmark layer, the January 11th wind event just below my snow saw. 1/30/2014.

Our new snowpack benchmark layer, the January 11th wind event just below my snow saw. 1/30/2014.


Bear Creek Meadows south aspect in a snow drought year. 1/30/2014.

Bear Creek Meadows south aspect in a snow drought year. 1/30/2014.


Bear Basin north aspect in a snow drought year. 1/30/2014.

Bear Basin north aspect in a snow drought year.
1/30/2014.

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 SNOWPACK DISCUSSION

Avalanche Problem #1

Storm Snow

Our storm event of January 29-30th, came in warm and finished cold.  A soft slab formed at the front end of the storm and was topped over by 6”- 9” of very soft snow.  This recent snow fell on the 1” layer of surface hoar that formed during our mountain fog cycle of last week.  Releases of this layer are easy and clean. 

 

 

 


 

Avalanche Problem #2 

Persistent Slab

We have been tracking this hard slab in the upper third of the snowpack for several weeks now.  It usually releases with moderate force and cleanly on large angular blocks.   As this slab gets buried under successive storms, we expect this slab to be problematic in a tricky way.            

 

 

 

TREND:  We expect storm loading to subside Friday.  Wind transport of available snow is NOT forecasted through Sunday with southwest winds at 2 – 5 mph.  Daytime high temperatures are forecasted to be below freezing through Sunday.  The trend is for hazard to stabilize by the end of this period. 

 


 

 BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range is MODERATE.  This means that heightened avalanche conditions exist on specific terrain features, such as steep unanchored slopes.  Natural avalanches are unlikely, however human triggered avalanches are possible.  Backcountry travelers should evaluate snow and terrain carefully, and identify features of concern.

SPECIAL NOTE:  We experienced significant storm loading at all sites in the last two days.  Forecasted winds to transport abundant available snow has yet to arrive. Watch the weather and avoid recently wind loaded slopes.

 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

 

 

Kootenai National Forest Avalanche Advisory – 1/28/2014

The avalanche information for the Kootenai National Forest is provided by Kootenai National Forest personnel. The Flathead Avalanche Center hosts this information on its website for the Kootenai National Forest.

THIS ADVISORY HAS EXPIRED.

Issued: Jan. 28, 2014 at 7:00 a.m. by Jon Jeresek
Expires: 11:59 p.m. of issue date

This advisory applies only to backcountry areas outside established ski area boundaries. The next scheduled advisory for the Kootenai National Forest area will be Friday, January 30, 2014. 


MOUNTAIN WEATHER 

WeatherGraphic

Since the Friday AM (January 24th) advisory, NO snow has fallen at Kootenai snotel sites (Banfield Mtn, Bear Mtn, Hawkins Lake, Poorman Cr).   Valley and mountain fog have been common.  The fog did NOT lift, temperatures below the fog remained below freezing.  Peaks that poked through the fog enjoyed daytime highs in the mid to upper 30s.  By Monday noon, skies have cleared over the region.  Winds have been very light out of the southwest with NO snow transport.

FORECAST:  The snow drought  MAY end!  Mostly cloudy skies Tuesday PM through Thursday.  Temperatures will be below freezing and drop to teens/low 20s at night.  Winds will be out of the southwest at 4 – 6 mph with a NO probability of snow transport through Thursday.  Chance of snow is 80-100% through Thursday, with accumulations of 10-15” forecasted.


 

RECENT OBSERVATIONS

RecentObservationsGraphicWe traveled to the Burnt Peak 6,300’ in the West Cabinets located 27 air miles west of Libby on January 27th.  70” to 80” of snow was encountered on northeast aspects above 6,000’ elevation.  After 15 days without storm/wind loading and near freezing day time high temperatures, all snowpacks continue to settle.  Near surface snow is topped with an inch plus of surface hoar that has developed over several nights.  Eight inches below the surface is a pink clay dust layer that the January 11th winds scoured off the Palousse in Idaho.  Below these surface layers are hard slabs which release cleanly with moderate force.  There is a very significant temperature gradient in the snowpack (surface -13 °C and -6 °C eight inches below) to drive change processes. 

Surface hoar thick enough to support a pencil.

Surface hoar thick enough to support a pencil.

 

The 1-11-2014 wind event that deposited the Palousse dust in our snowpack.

The 1-11-2014 wind event that deposited the Palousse dust in our snowpack.

 

East Cabinets from Burnt Peak.

East Cabinets from Burnt Peak.

   

 

 

 

 

 

 

 

 


 SNOWPACK DISCUSSION

Avalanche Problem #1

Wind Slab16 days ago heavy storm loading followed by the January 11th and 13th wind transport have developed wind deposits overlaying a sensitive snowpack.  Back country travelers should identify and avoid these wind deposition areas.

 

 

 


 

Avalanche Problem #2 

Persistent Slab

We have been tracking this hard slab in the upper third of the snowpack for several weeks now.  It usually releases easily and cleanly on small sized facets.  When our current snow drought ends, we expect this slab to be problematic in a tricky way            

 

 

 

TREND:  We expect significant storm loading Tuesday afternoon through Thursday. Daytime high temperatures are forecasted to be below freezing through Thursday.  The trend is for avalanche hazard to increase by the end of this period because of heavy additional load on top of near surface weak layers.

 


 

 BOTTOM LINE

The avalanche hazard in the West Cabinets, East Cabinets and Purcell Range for today is MODERATE.  This means that heightened avalanche conditions exist on specific terrain features, such as steep unanchored slopes.  Natural avalanches are unlikely, however human triggered avalanches are possible.  Backcountry travelers should evaluate snow and terrain carefully, and identify features of concern.

SPECIAL NOTE:  We continue to advise backcountry travelers to avoid the easterly aspects near ridgelines, as a result of the westerly wind events of January 11 and 13th.

 


 DISCLAIMER

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 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.