A stationary front fed by a rich plume of Pacific moisture followed by the passage of a  surface low pressure brought heavy snow to the mountains and valleys of north Idaho beginning on the 28th of December and continuing through the 30th. As the surface low pressure approached a tongue of warm air aloft produced freezing rain in addition to snow in the Coeur D'Alene area. The warm front never migrated any farther north and the mountains and valleys of the northern Idaho Panhandle received heavy snow until the storm ended. South of the warm front, over the Idaho Palouse region and the valleys of the central Panhandle heavy rain fell with St. Maries reporting 1.26 inches of rain, Potlatch receiving 2.21 inches and Lewiston 1.33 inches. This rainfall combined with melting low elevation snow triggered mudslides and debris flows as well as forcing Paradise Creek near Moscow briefly above Flood Stage.

Flood in LATAH, IDAHO
From 29-DEC-17 20:45:00 to 29-DEC-17 23:00:00 (PST-8)
Location: MOSCOW
Flood cause: Heavy Rain / Snow Melt
Property damage: 0.50K
Crop damage: 0.00K
Reported by: River/Stream Gage

The USGS river gage at Paradise Creek in Moscow recorded a sharp rise above the Flood Stage of 9.2 feet at 8:45 PM December 29th. The creek quickly crested at 9.7 feet by 9:00 PM and then receded back below Flood Stage by 11:00 PM. No damage was reported with this minor flood.

Debris Flow in LEWIS, IDAHO
From 30-DEC-17 06:00:00 to 30-DEC-17 12:00:00 (PST-8)
Location: KAMIAH
Flood cause: Heavy Rain / Snow Melt
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy rain and snow melt saturated the ground and caused a Debris Flow near Kamiah. The mudslide cut and temporarily closed Idaho Highway 64 between Nez Perce and Kamiah.

Debris Flow in NEZ PERCE, IDAHO
From 30-DEC-17 07:00:00 to 30-DEC-17 09:00:00 (PST-8)
Location: PECK
Flood cause: Heavy Rain / Snow Melt
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy rain and snow melt saturated the ground and caused a Debris Flow near Peck. The mudslide was reported to be 3 to 4 feet deep and about 30 feet wide across Sunnyside Bench Road.

Heavy Snow in NORTHERN PANHANDLE, IDAHO
From 28-DEC-17 23:00:00 to 30-DEC-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 3 miles north of Clark Fork reported 34.5 inches of new snow accumulation over the previous 3 days.

Heavy Snow in NORTHERN PANHANDLE, IDAHO
From 28-DEC-17 23:00:00 to 30-DEC-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A member of the public in Sandpoint reported 12.0 inches of new snow accumulation.

Heavy Snow in NORTHERN PANHANDLE, IDAHO
From 28-DEC-17 23:00:00 to 30-DEC-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A member of the public near Colburn reported 10.0 inches of new snow accumulation.

Heavy Snow in COEUR D'ALENE AREA, IDAHO
From 29-DEC-17 05:00:00 to 29-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter in Coeur D'Alene reported 8.0 inches of new snow accumulation.

Heavy Snow in COEUR D'ALENE AREA, IDAHO
From 29-DEC-17 05:00:00 to 29-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A member of the public in Rathdrum reported 6.0 inches of new snow accumulation.

Heavy Snow in NORTHERN PANHANDLE, IDAHO
From 28-DEC-17 23:00:00 to 30-DEC-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter 9 miles south of Elmira reported 9.8 inches of new snow accumulation.

Heavy Snow in CENTRAL PANHANDLE MOUNTAINS, IDAHO
From 28-DEC-17 12:00:00 to 30-DEC-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A member of the public in Pinehurst reported 16.0 inches of new snow accumulation.

Heavy Snow in COEUR D'ALENE AREA, IDAHO
From 29-DEC-17 05:00:00 to 29-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A member of the public in Post Falls 4.0 inches of new snow accumulation.

Heavy Snow in CENTRAL PANHANDLE MOUNTAINS, IDAHO
From 28-DEC-17 12:00:00 to 30-DEC-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A member of the public in Wallace reported 12.0 inches of new snow accumulation.

Heavy Snow in NORTHERN PANHANDLE, IDAHO
From 28-DEC-17 23:00:00 to 30-DEC-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer in Bonners Ferry reported 16.3 inches of storm total snow accumulation over the past 2 days.

Ice Storm in COEUR D'ALENE AREA, IDAHO
From 29-DEC-17 18:00:00 to 29-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

As the winter storm ended snow turned over to freezing rain mainly in the Coeur D'Alene area. A spotter noted about 1 inch of ice accumulation with scattered power outages and downed trees during the late evening hours.

Ice Storm in COEUR D'ALENE AREA, IDAHO
From 29-DEC-17 18:00:00 to 29-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter near Athol reported 6 to 8 inches of snow during the day, with a change over to freezing rain around 6:00 PM with about 0.25 inch of ice accumulation.

Heavy Snow in NORTHERN PANHANDLE, IDAHO
From 28-DEC-17 23:00:00 to 30-DEC-17 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The Schweitzer Mountain ski resort reported 20 inches of new snow from this storm.

Heavy Snow in CENTRAL PANHANDLE MOUNTAINS, IDAHO
From 28-DEC-17 12:00:00 to 30-DEC-17 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The lookout Pass ski resort reported a storm total of 50 inches of snow at the summit from this storm system.