A prolonged period of high pressure helped to strengthen temperature inversions across northwest Montana by the end of November. This allowed for cold pools to develop while temperatures in the higher elevations were able to warm into the 30's and even 40's in a few locations. The upper level flow became more northwesterly allowing for Pacific moisture to sneak around the ridge by Nov. 29th. This created a setup for freezing rain which caused slick roads, and other surfaces including sidewalks across northwest Montana.

Winter Weather in KOOTENAI/CABINET REGION, MONTANA
From 29-NOV-13 22:00:00 to 29-NOV-13 23:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A weather spotter in Troy reported freezing rain. They believed that the ice was forming on nearby roads making for slick conditions.

Winter Weather in POTOMAC / SEELEY LAKE REGION, MONTANA
From 29-NOV-13 17:00:00 to 30-NOV-13 11:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The trained weather spotter one mile south of Condon reported 1/8th of an inch of ice from freezing rain Friday evening, November 29 through Saturday morning, November 30.

Winter Weather in FLATHEAD/MISSION VALLEYS, MONTANA
From 29-NOV-13 02:00:00 to 30-NOV-13 23:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The MTDOT section between Kalispell and Whitefish, reported a layer of glaze that caused road surfaces to be slick during the early morning hours from 4 to 7 am MST on Nov. 29. A weather spotter from Columbia Falls reported freezing drizzle during the morning of Nov. 29 precipitating out of fog.  This spotter overheard multiple reports of vehicles spinning out due to the slick roads. A weather spotter located just west of Kalispell reported that mist developed during the early morning hours of Nov. 29 that caused sidewalks to become slick.  Light snow fell from 4 to 6:30 pm MST on Nov. 29 in the Kalispell area. The Flathead County 911 dispatch indicated that the combination of snow on top of icy conditions caused a few accidents and slide-offs. The Lake County 911 dispatch reported icy roads at Terrace Lake in the Ronan area at 9 am MST on Nov. 30. A spotter 8 mi. northwest of St. Ignatius reported freezing rain that caused the sidewalks to become icy during the late morning hours of Nov. 30. At 11:01 pm MST on Nov. 30, a spotter located in Columbia Falls tweeted that roads were solid sheets of ice due to freezing rain and were treacherous. They reportedly drove down East Tamarack Hill sideways.

Winter Weather in LOWER CLARK FORK REGION, MONTANA
From 29-NOV-13 14:53:00 to 30-NOV-13 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The MTDOT reported freezing rain at Lookout Pass on Interstate 90 at 2:25 am MST on Nov. 30. The Mineral County sheriff office in Superior reported freezing rain, slick conditions on I-90 and multiple reports of accidents.

Dense Fog in FLATHEAD/MISSION VALLEYS, MONTANA
From 26-NOV-13 20:35:00 to 27-NOV-13 15:15:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

As a NWS employee drove north on US-93 on Nov. 27, they encountered dense freezing fog with visibilities less than one quarter mile from the animal's bridge north for 5 miles and also from Ronan north to Pablo. In Ronan they interviewed a salesman at the Chevrolet dealer, who reported that a light dusting of snow fell when the fog moved in from the north earlier in the morning.  In Pablo, they reported light freezing drizzle creating a glaze on untreated surfaces near the People's Center museum. The Ronan Airport AWOS sensor, located 2.6 miles north of Ronan, reported visibility at or below one-half mile from the late evening of Nov. 26 through the afternoon on Nov. 27. The one-quarter mile visibility was observed from 8:55 am MST through 2:35 pm MST on Nov. 27.