THIS SNOWPACK SUMMARY EXPIRED ON February 18, 2017 @ 11:25 amSnowpack Summary published on February 17, 2017 @ 6:25 pm
Issued by
Ben Bernall - Kootenai National Forest
Avalanche Character 1: Loose Wet
Loose Wet avalanches occur when water is running through the snowpack, and release at or below the trigger point. Avoid very steep slopes and terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
Although we are dealing with a relatively stable snowpack we are entering that time of year when we are experiencing rapid changes in temperature from day to day. Rising temperatures will have the potential to cause loose wet slides on aspects that are receiving intense afternoon sun.
The best way to manage this potential hazard is to avoid steep slopes that are recieving intense, afternoon sun. Plan your travels accordingly and pay close attention to the slopes that you may have to cross at the end of the day.
Avalanche Character 2: Persistent Slab
Persistent Slab avalanches can be triggered days to weeks after the last storm. They often propagate across and beyond terrain features that would otherwise confine Wind and Storm Slab avalanches. In some cases they can be triggered remotely, from low-angle terrain or adjacent slopes. Give yourself a wide safety buffer to address the uncertainty.
There are multiple rain crusts in the snowpack that are not currently reactive in stability tests; but, these layers provide the opportunity for avalanches that could be triggered by sun or the previously mentioned wet slides.
Again, the best option for dealing with these potential weaknesses is to avoid steep, sunny aspects in the afternoon and pay close attention to signs of a warming snowpack.
recent observations
Today (Friday, February 17th) we traveled into the Cabinet Mountain Wilderness near the Smearl Creek drainage. We found evidence of both loose wet slides and some small slab avalanches that appeared to have released during Thursdays rain event. The rain left its mark as high as we could see on the highest peaks of the Cabinets (over 8,000"). As the rain left and the temperatures dropped the snowpack has stabilized significantly. Stability test results showed a stable snowpack on a north aspect at 6,500'. Southerly aspects were taking on alot of sun and some roller activity was picking up but no slides were observed during the afternoon sun.
If you are riding near the Idaho line check out the Panhandle Forecast by clicking the link below:
http://www.idahopanhandleavalanche.org/current-advisory.html
Weather and CURRENT CONDITIONS
weather summary
Backcountry Forecast from NWS Missoula issued:
230 PM MST Fri Feb 17 2017
DISCUSSION:
Southwest flow will persist over the Northern Rockies for the next
couple of days with subtle disturbances making their way through
the flow. Snow levels will be fluctuating between 3000 to 5000
feet. This active weather pattern will persist through at least
mid next week.
Kootenai:
--------------------------- 5000-7000 FT ----------------------------
Tonight Sat Sat Night Sun
Cloud Cover 60% 95% 95% 80%
Hi/Lo Temps 21 to 25 31 to 34 23 to 28 31 to 36
Winds(mph) E 7G21 SE 7 SW 7 SW 7
Precip Chc 0 80 100 60
Precip Type none sno/shr sno/shr sno/shr
Liquid Amt 0.00 0.17 0.16 0.06
Snow Ratio(SLR) 0 14:1 15:1 16:1
Snow Amt(in) 0 1 1-2 1
Snow Level 3500 3000 2500 2500
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 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.
