On December 19th a very moist surface low pressure tracked through eastern Washington and north Idaho along a warm front. The Columbia Basin was mainly south of the warm front with mostly rain, although the northern margin of the basin including the Spokane area received 2 to 4 inches of heavy wet snow before changing to rain during the day as the warm front passed through and stalled just to the north. The mountains and valleys north of the basin and the Cascades remained in the cold air mass north of the stalled warm front and received a prolonged period of heavy snow from this storm. In addition to travel difficulties, heavy wet snow caused numerous power outages for the residents of valley communities in these mountainous zones.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The observer at Holden Village recorded 23.9 inches of storm total snow.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The observer at Mazama recorded 12.6 inches of storm total snow.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The observer at Plain recorded 8.1 inches of storm total snow.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The observer at Stehekin recorded 9.0 inches of storm total snow.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 5 miles south of Peshastin reported 10.3 inches of new snow.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer in Leavenworth reported 7.1 inches of new snow.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Ardenvior reported 5.9 inches of new snow.

Heavy Snow in EAST SLOPES NORTHERN CASCADES, WASHINGTON
From 18-DEC-17 20:00:00 to 19-DEC-17 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 7 miles northwest of Winthrop reported 10.3 inches of new snow.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 21:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

An observer in Republic recorded 6.0 inches of storm total snow.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer in Colville recorded 8.4 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer at Newport recorded 11.0 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer at Newport recorded 6.5 inches of storm total snow accumulation.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The 49 North ski resort reported 30 inches of storm total snow.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Evans reported 4.5 inches of new snow.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Clayton reported 7.0 inches of new snow.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer near Elk reported 8.0 inches of new snow.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 21:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 7 miles north of Republic reported 6.5 inches of new snow.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 21:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer 7 miles north of Republic reported 6.5 inches of new snow.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A citizen near Rice reported 12.1 inches of new snow.

Heavy Snow in OKANOGAN HIGHLANDS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 21:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

An observer at Boyds reported 11.9 inches of storm total snow.

Heavy Snow in NORTHEAST MOUNTAINS, WASHINGTON
From 18-DEC-17 22:00:00 to 19-DEC-17 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter near Diamond Lake reported 12.8 inches of new snow.