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.
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.
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.
Avalanche Problem #1
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
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.
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.
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.