Current NW Montana Avalanche Advisory

INTRODUCTION:
This is Stan Bones with the backcountry avalanche advisory issued by the U.S. Forest Service Glacier Country Avalanche Center at 6:30 AM, Friday, February 5th, 2010, for the GlacierParkand Flathead and KootenaiNational Forestareas.

WEATHER ANALYSIS:
This past week much of NW Montana endured another spell of mostly dry, mild weather. Variable degrees of high pressure defended much of the region from any significant storm activity. The N'ern Swan Range and the Mission Range appear to be the only exceptions as they picked up 1-1.5 inches of snow water equivalent total in two storms Sunday and Tuesday. Since Wednesday dry air has returned. Winds over the last week have generally be light to non-existent. Air temperatures at many mtn locations have been mild with daytime highs often hovering around freezing and nighttime lows down into the mid to low 20's F. Wednesday saw the biggest push above freezing as daytime clearing developed over much of the region. The heating however was short lived, peaking rapidly around noon.

A poling of the snotel stations around the region are currently showing the Kootenai River Basin at 73% of average snow water equivalent, while the Flathead River Basin registers 77% of average. Moss Peak above Finely Point in the Missions and Noisy Basin in the Jewel Basin area of the N Swans appear to be the only locations nearing normal. Many of the other higher and lower elevations sites swarm in the 70-90% range. Pike Creek near Marias Pass on the the Continental Divide has the lowest reading at 44% of average.

SNOWPACK ANALYSIS:
Our backcountry observations on Thursday were in the Lost Johnny Creek area on the east slope of the N'ern Swan Range , NE of Bigfork, and on Baree Mtn in the East Cabinet Range south of Libby on the Kootenai. On Wednesday we received a report on conditions near Snow Slip in the John Stevens Canyon area along the S'ern edge of Glacier Park.

In our backcountry tours and snowpit investigations and the report we received, we're continuing to see a snowpack that is strengthening as it settles and consolidates. The mid pack weaknesses we were tracking earlier appear to be abating. The basal weakness is slowly gaining strength and for the most part appears to be bridged over currently by the strength of the snow layers above. The most significant weaknesses are concentrated near the surface and these are causing minimal concern currently. They bear minding however, as one watches future storms develop.

We are not seeing, nor have we received any reports of recent slab avalanche activity. There has been some minor loose, point releases on S and W aspects with the recent solar warming.

AVALANCHE - INSTABILITY DESCRIPTION:
We're currently rating the avalanche danger between the elevations of 5,500 and 7,500 ft. as MODERATE on all large, steep, open slopes lacking vegetative and terrain anchors. Unstable deep slab layers are possible. Natural avalanches are unlikely, but human triggered avalanches remain possible. Backcountry travelers should use caution in big, steep, open terrain on all aspects. Watch particularly during period of thaw.

On anchored slopes below 7,500 ft. and all slopes, all aspects, below 5,500 ft., we're rating the avalanche danger as LOW. The anchored or shallow snow there is generally stable with only isolated areas of instability. Natural avalanches are very unlikely, while human triggered avalanches are unlikely. Backcountry travel is generally safe. Normal caution is advised. Backcountry travelers need to always realize that LOW avalanche danger is not the same as NO avalanche danger.

WEATHER FORECAST & AVALANCHE OUTLOOK:

The weather forecast is for a weak warm front to push across NW Montana Friday. Snowfall amounts are expected to be light at only an inch or two, and that mostly confined to the higher elevations. Winds are forecasted Friday to be light from the SE, while air temperatures are expected to be in the upper 20's and lower 30's. Over the weekend an even weaker disturbance is forecasted. This should keep cloudiness over the region with some very light snow showers Saturday and Sunday. Winds should remain light and temperatures mild. A lack of significant weather activity will maintain the avalanche danger near current levels.

Backcountry travelers need to maintain suspicion of large, steep, open slopes on all aspects. Continue to practice safe route selection and travel techniques. Always carry and know how to use avalanche safety equipment.

 

The beacon park located atop Big Mountain, is up and running. Just west of the Chair One terminal, it is in a convenient location for hopping off of your snowmobile or shuffling out of the Summit House and practicing a transceiver search. The Big Mountain Ski Patrol will assist anyone having questions, so make time to go and practice.

This evening, Friday, Feb. 5, Glacier Country Avalanche Center will be hosting a talk by Sam Kavanagh and a showing of the film A Dozen More Turns. This program is a fund raiser for GCAC and will be at the Glacier Discovery Square in Columbia Falls beginning at 7:00 PM. Cost is $5 at the door. Check the GCAC website (www.glacieravalanche.org) for more information about this very informative and inspiring presentation.

Our next regular update of this advisory message will be Tuesday, February 9th.

Flathead Valley & Outside Montana  -- 406-257-8402
Toll-free Within Montana -- 1-800-526-5329

Report your avalanche observations and incidents here

In an effort to improve our service to the public we are attempting to define the users of this advisory message. Please contact us with a message listing your backcountry interests. Are you a snowmobiler, snowboarder, mountaineer, snowshoer, or skier? Also let us know where you reside.
 

Thank you for your continuing support of Northwestern Montana's Glacier Country Avalanche Center.