
Kootenai

Cold temperatures have locked the upper snowpack together following Thursdays' warm and wet weather. Generally stable snowpack conditions will exist on Friday with the potential to find isolated pockets of wind slab at upper elevations on leeward terrain. Expect windslabs and stormslabs to increase in size and sensitivity going into the weekend.
Kootenai
How to read the advisory
Cold temperatures have locked the upper snowpack together following Thursdays' warm and wet weather. Generally stable snowpack conditions will exist on Friday with the potential to find isolated pockets of wind slab at upper elevations on leeward terrain. Expect windslabs and stormslabs to increase in size and sensitivity going into the weekend.

2. Moderate
?
Above Treeline
2. Moderate
?
Near Treeline
2. Moderate
?
Below Treeline
-
Type ?
-
Aspect/Elevation ?
-
Likelihood ?CertainVery LikelyLikelyPossibleUnlikely
-
Size ?HistoricVery LargeLargeSmall
On Thursday night a cold front pushed out the rain and warm air with high winds and a trace of new snow. Area snotel sites recorded 1-3" of new snow with Hawkins Lake Snotel finally scoring a win at 5" of new snow accumulation. This new snow snow should bond relatively quickly to the warm and moist surface of the existing snowpack. The NWS mountain forecast for the area is calling for 2-3" of snow Friday night and 5-7" Saturday with more southwesterly winds. This will increase the size and sensitivity of these slabs moving into the weekend.
-
Type ?
-
Aspect/Elevation ?
-
Likelihood ?CertainVery LikelyLikelyPossibleUnlikely
-
Size ?HistoricVery LargeLargeSmall
With forecast calling for up to 10" of new snow in the mountains on Friday night and Saturday we can expect the development of small storm slabs by Saturday morning. Take the time to observe and assess the bonding strength of this new snow on steep slopes before committing. It is difficult to predict at this point what the potential will be on Saturday. The potential for a storm slab problem and its sensitivity will vary, much of this will depend on the temperatures during the next storm and the variable surfaces that the new snow is landing on. At lower elevations this new snow is likely to fall on Thursdays slick melt-freeze crust. Again, best to assess individual slopes on Saturday before committing to steep terrain.
Yesterday we toured into the Cabinet Mountains to test out the water resistance of our ski gear. At 6,000' in elevation we finally found the rain-snow transition line, I believe the operative word used by my partner was "yuck". We travelled as high as 7,600' where we found new snow amounts of 3-4" that were extremely wet and sticky. We performed stability tests on a northeast aspect at 6,800' and the snowpack had no failures or propagation. At this location we were unable to find evidence of the surface hoar that has been prevalent in sheltered locations 10-14" below the surface. We also reaffirmed our theory that at this elevation the February 4th rain crust disappears. The most important observations taken from the day were the amount of moisture being absorbed by the upper 12" of snow, even at elevations above the rain line the top foot of snow is very wet. We also observed two "loose-wet" slides that released on a north aspect at 7,000' yesterday. This thawing and rain, followed by the cold temperatures that moved in on Friday morning will have the snowpack "locked-up" and relatively stable through Friday. Much of the forecast is based on the potential for new snow and strong southwesterly winds predicted for Friday night and Saturday. As I mentioned in the "Problems" section, there are multiple variables that will affect the potential of the storm slab problem on Saturday. Use caution on each aspect and elevation change until you have verified the bonding strength of the new snow Saturday.
Backcountry Forecast from NWS Missoula issued: 350 AM MDT Fri Mar 23 2018 DISCUSSION: In the wake of last night's cold front, temperatures have trended cooler and a few lingering snow showers will be possible throughout today. However, only light accumulations are expected. Another cold front will begin pushing into north-central Idaho and western Montana by late tonight into Saturday. Snow showers and gusty west-southwest winds will be on the increase, and showers could be locally heavy at times overnight into Saturday. Snow total accumulations in the terrain of northwest Montana could reach 6-10 inches (locally higher). Saturday's max temperatures will struggle to get above freezing for most of the mountains. Northwest flow will set up Sunday and into next week, leading to a few light showers and a gradual warming trend. Kootenai: --------------------------- 5000-7000 FT ---------------------------- Today Tonight Sat Cloud Cover 50% 85% 85% Hi/Lo Temps 30 to 38 20 to 27 27 to 35 Winds(mph) SW 18G37 S 10G25 SW 18G61 Precip Chc 40 70 100 Precip Type sno/shr sno/shr sno/shr Liquid Amt 0.02 0.14 0.33 Snow Ratio(SLR) 16:1 15:1 15:1 Snow Amt(in) 0 2-3 5-7 Snow Level 1500 2500 2000
Avalanche conditions change for better or worse continually. Backcountry travelers should be prepared to assess current conditions for themselves, plan their routes of travel accordingly, and never travel alone. Backcountry travelers can reduce their exposure to avalanche hazards by utilizing timbered trails and ridge routes and by avoiding open and exposed terrain with slope angles of 30 degrees or more. Backcountry travelers should carry the necessary avalanche rescue equipment such as a shovel, avalanche probe or probe ski poles, a rescue beacon and a well-equipped first aid kit. For a recorded version of the Avalanche Advisory call (208)765-7323.
This website is owned and maintained by the Friends of the Idaho Panhandle Avalanche Center. Some of the content is updated by the USDA avalanche forecasters including the forecasts and some observational data. The USDA is not responsible for any advertising, fund-raising events/information, or sponsorship information, or other content not related to the forecasts and the data pertaining to the forecasts.