Winter Weather Advisory issued December 18 at 2:34AM MST until December 19 at 5:00PM MST by NWS Missoula MT

…ATMOSPHERIC RIVER TO BRING SIGNIFICANT MOUNTAIN SNOW…

.A plume of subtropical moisture associated with an atmospheric
river will bring significant mountain snow Thursday into Friday.
Snow levels will rise above 5,000 feet Thursday night before quickly
dropping Friday morning as strong cold front passes. The heaviest
snow accumulations will impact higher elevations above 6,000 feet,
especially across the Clearwater and Bitterroot Mountains.

* WHAT…Snow expected above 6500 feet. There is a likelihood of
moderate to isolated major winter weather impacts. Total snow
accumulations between 10 and 20 inches. Winds gusting as high as
55 mph.

* WHERE…Williams Creek Summit.

* WHEN…From 1 PM this afternoon to 5 PM MST Friday.

* IMPACTS…For MODERATE winter weather impacts, expect disruptions
to normal activities. Hazardous traveling conditions. Use extra
caution while driving. Closures and disruptions to infrastructure
may occur.
Slow down and use caution while traveling. The latest road
conditions for the state you are calling from can be obtained by
calling 5 1 1.