?
Above 6500 ft.
?
5000-6500 ft.
?
3500-5000 ft.
Since Wednesday remote weather stations in the Swan Range have shown fairly warm temperatures and a shrinking snowpack. I would expect to find dust on crust conditions throughout the range today. Exercise safe travel protocol and travel one at a time through avalanche terrain.
It is clear that previous snowfall from Dec 9th glanced the northern part of the forecast zone and left the rest of the area mostly high and dry. Stahl Peak picked up a whopping 1.6 inches of snow water equivielent (SWE) and Flattop in Glacier National Park picked up 1.2 inches of SWE. Though some of this precipitation likely fell as rain, I would still expect to find roughly 8 to 12 inches of new snow in favored areas.
A rider in the northern Whitefish Range found about 8 inches of snow yesterday. Meanwhile, Blase found a meager 1 to 2 inches at Big Mountain and I found similar accumulations in the Flathead Range. There is uncertainty about how far south this storm system tracked and whether the Lake McDonald area received any noteworthy accumulations.
The reason I bring all of this up is to stress the importance of paying attention to snow depths in the specific area you are traveling. If you are only finding 1 to 2 inches of new snow, expect low hazard conditions. These areas will likely include the southern Whitefish Range, Flathead Range, Swan Range, and the south end of Glacier. If you do decide to go powder chasing up north, which I think would be the most fun, you will find more snow, and thus more of an avalanche hazard. If you find more than 8 inches of new snow under your feet or machine, watch for shooting cracks in recently wind drifted snow. Manage your sluff in wind-sheltered terrain since it will slide easily on the recently buried crust.
There is still uncertainty about where surface hoar and near-surface facets were preserved and buried underneath the new snow. In the southern part of the Whitefish Range, Blase and our friends at WMR found surface hoar preserved under the few inches of snow that fell. Other areas reported no signs of this weak layer. Much of it likely got destroyed by sun, wind, and rain. The biggest hazard right now would be if it got preserved where 8 or more inches of new snow fell. This would make for a more dangerous hazard since avalanches could propagate long distances. If you feel whumpfing collapses or find a grey looking stripe at the new/old snow interface, seek out terrain with slope angles less than roughly 30 degrees. Your observations are incredibly helpful.
The beacon park is set up and ready for use at Whitefish Mountain Resort. A big thanks to all that helped set it up for our community.
Today expect mild conditions before heading into a more active pattern. Winds will be light out of the east with temperatures in the low to mid 20s. No precipitation is expected until this evening with a possible trace to 2 inches overnight.
| Friday | Friday Night | Saturday | |
|---|---|---|---|
| Cloud Cover: | Mostly Cloudy | Mostly Cloudy | Partly Cloudy |
| Temperatures: | 20 to 25 deg. F. | 11 to 15 deg. F. | 18 to 23 deg. F. |
| Wind Direction: | East | East | West |
| Wind Speed: | 5 to 10 | 9 | 9 |
| Snowfall: | 0" in. | 1" to 2" in. | 0" in. |
| Snow Line: | 1000' | 1000' | 1000' |
This forecast applies only to backcountry areas outside established ski area boundaries. The forecast describes general avalanche conditions and local variations always occur. This forecast expires at midnight on the posted day unless otherwise noted. The information in this forecast is provided by the USDA Forest Service who is solely responsible for its content.
